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514094f9 | 1 | <?xml version='1.0'?> |
3a54a157 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
7a8aa0ec | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [ |
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4 | <!ENTITY % entities SYSTEM "custom-entities.ent" > |
5 | %entities; | |
7a8aa0ec | 6 | ]> |
db9ecf05 | 7 | <!-- SPDX-License-Identifier: LGPL-2.1-or-later --> |
8f7a3c14 | 8 | |
dfdebb1b | 9 | <refentry id="systemd-nspawn" |
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10 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
11 | ||
12 | <refentryinfo> | |
13 | <title>systemd-nspawn</title> | |
14 | <productname>systemd</productname> | |
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15 | </refentryinfo> |
16 | ||
17 | <refmeta> | |
18 | <refentrytitle>systemd-nspawn</refentrytitle> | |
19 | <manvolnum>1</manvolnum> | |
20 | </refmeta> | |
21 | ||
22 | <refnamediv> | |
23 | <refname>systemd-nspawn</refname> | |
a7e2e50d | 24 | <refpurpose>Spawn a command or OS in a light-weight container</refpurpose> |
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25 | </refnamediv> |
26 | ||
27 | <refsynopsisdiv> | |
28 | <cmdsynopsis> | |
29 | <command>systemd-nspawn</command> | |
30 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
31 | <arg choice="opt"><replaceable>COMMAND</replaceable> | |
32 | <arg choice="opt" rep="repeat">ARGS</arg> | |
33 | </arg> | |
34 | </cmdsynopsis> | |
35 | <cmdsynopsis> | |
36 | <command>systemd-nspawn</command> | |
4447e799 | 37 | <arg choice="plain">--boot</arg> |
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38 | <arg choice="opt" rep="repeat">OPTIONS</arg> |
39 | <arg choice="opt" rep="repeat">ARGS</arg> | |
40 | </cmdsynopsis> | |
41 | </refsynopsisdiv> | |
42 | ||
43 | <refsect1> | |
44 | <title>Description</title> | |
45 | ||
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46 | <para><command>systemd-nspawn</command> may be used to run a command or OS in a light-weight namespace |
47 | container. In many ways it is similar to <citerefentry | |
48 | project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, but more powerful | |
49 | since it fully virtualizes the file system hierarchy, as well as the process tree, the various IPC subsystems and | |
50 | the host and domain name.</para> | |
51 | ||
5164c3b4 | 52 | <para><command>systemd-nspawn</command> may be invoked on any directory tree containing an operating system tree, |
b09c0bba | 53 | using the <option>--directory=</option> command line option. By using the <option>--machine=</option> option an OS |
5164c3b4 | 54 | tree is automatically searched for in a couple of locations, most importantly in |
3b121157 | 55 | <filename>/var/lib/machines/</filename>, the suggested directory to place OS container images installed on the |
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56 | system.</para> |
57 | ||
58 | <para>In contrast to <citerefentry | |
59 | project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command> | |
60 | may be used to boot full Linux-based operating systems in a container.</para> | |
61 | ||
62 | <para><command>systemd-nspawn</command> limits access to various kernel interfaces in the container to read-only, | |
3b121157 | 63 | such as <filename>/sys/</filename>, <filename>/proc/sys/</filename> or <filename>/sys/fs/selinux/</filename>. The |
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64 | host's network interfaces and the system clock may not be changed from within the container. Device nodes may not |
65 | be created. The host system cannot be rebooted and kernel modules may not be loaded from within the | |
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66 | container.</para> |
67 | ||
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68 | <para>Use a tool like <citerefentry |
69 | project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry | |
70 | project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or | |
71 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> to | |
72 | set up an OS directory tree suitable as file system hierarchy for <command>systemd-nspawn</command> containers. See | |
73 | the Examples section below for details on suitable invocation of these commands.</para> | |
74 | ||
75 | <para>As a safety check <command>systemd-nspawn</command> will verify the existence of | |
76 | <filename>/usr/lib/os-release</filename> or <filename>/etc/os-release</filename> in the container tree before | |
926f2a04 | 77 | booting a container (see |
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78 | <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). It might be |
79 | necessary to add this file to the container tree manually if the OS of the container is too old to contain this | |
798d3a52 | 80 | file out-of-the-box.</para> |
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81 | |
82 | <para><command>systemd-nspawn</command> may be invoked directly from the interactive command line or run as system | |
83 | service in the background. In this mode each container instance runs as its own service instance; a default | |
84 | template unit file <filename>systemd-nspawn@.service</filename> is provided to make this easy, taking the container | |
85 | name as instance identifier. Note that different default options apply when <command>systemd-nspawn</command> is | |
6dd6a9c4 | 86 | invoked by the template unit file than interactively on the command line. Most importantly the template unit file |
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87 | makes use of the <option>--boot</option> option which is not the default in case <command>systemd-nspawn</command> |
88 | is invoked from the interactive command line. Further differences with the defaults are documented along with the | |
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89 | various supported options below.</para> |
90 | ||
91 | <para>The <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> tool may | |
92 | be used to execute a number of operations on containers. In particular it provides easy-to-use commands to run | |
93 | containers as system services using the <filename>systemd-nspawn@.service</filename> template unit | |
94 | file.</para> | |
95 | ||
96 | <para>Along with each container a settings file with the <filename>.nspawn</filename> suffix may exist, containing | |
97 | additional settings to apply when running the container. See | |
98 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry> for | |
99 | details. Settings files override the default options used by the <filename>systemd-nspawn@.service</filename> | |
100 | template unit file, making it usually unnecessary to alter this template file directly.</para> | |
101 | ||
102 | <para>Note that <command>systemd-nspawn</command> will mount file systems private to the container to | |
3b121157 | 103 | <filename>/dev/</filename>, <filename>/run/</filename> and similar. These will not be visible outside of the |
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104 | container, and their contents will be lost when the container exits.</para> |
105 | ||
106 | <para>Note that running two <command>systemd-nspawn</command> containers from the same directory tree will not make | |
107 | processes in them see each other. The PID namespace separation of the two containers is complete and the containers | |
3a9d9f2a | 108 | will share very few runtime objects except for the underlying file system. Rather use |
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109 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s |
110 | <command>login</command> or <command>shell</command> commands to request an additional login session in a running | |
111 | container.</para> | |
112 | ||
113 | <para><command>systemd-nspawn</command> implements the <ulink | |
53dc5fbc | 114 | url="https://systemd.io/CONTAINER_INTERFACE">Container Interface</ulink> specification.</para> |
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115 | |
116 | <para>While running, containers invoked with <command>systemd-nspawn</command> are registered with the | |
117 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> service that | |
118 | keeps track of running containers, and provides programming interfaces to interact with them.</para> | |
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119 | </refsect1> |
120 | ||
121 | <refsect1> | |
122 | <title>Options</title> | |
123 | ||
b47013fd | 124 | <para>If option <option>--boot</option> is specified, the arguments |
3f2d1365 | 125 | are used as arguments for the init program. Otherwise, |
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126 | <replaceable>COMMAND</replaceable> specifies the program to launch |
127 | in the container, and the remaining arguments are used as | |
b09c0bba | 128 | arguments for this program. If <option>--boot</option> is not used and |
ff9b60f3 | 129 | no arguments are specified, a shell is launched in the |
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130 | container.</para> |
131 | ||
132 | <para>The following options are understood:</para> | |
133 | ||
134 | <variablelist> | |
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135 | |
136 | <varlistentry> | |
137 | <term><option>-q</option></term> | |
138 | <term><option>--quiet</option></term> | |
139 | ||
140 | <listitem><para>Turns off any status output by the tool | |
141 | itself. When this switch is used, the only output from nspawn | |
142 | will be the console output of the container OS | |
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143 | itself.</para> |
144 | ||
145 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
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146 | </varlistentry> |
147 | ||
148 | <varlistentry> | |
149 | <term><option>--settings=</option><replaceable>MODE</replaceable></term> | |
150 | ||
151 | <listitem><para>Controls whether | |
152 | <command>systemd-nspawn</command> shall search for and use | |
153 | additional per-container settings from | |
154 | <filename>.nspawn</filename> files. Takes a boolean or the | |
155 | special values <option>override</option> or | |
156 | <option>trusted</option>.</para> | |
157 | ||
158 | <para>If enabled (the default), a settings file named after the | |
159 | machine (as specified with the <option>--machine=</option> | |
160 | setting, or derived from the directory or image file name) | |
161 | with the suffix <filename>.nspawn</filename> is searched in | |
162 | <filename>/etc/systemd/nspawn/</filename> and | |
163 | <filename>/run/systemd/nspawn/</filename>. If it is found | |
164 | there, its settings are read and used. If it is not found | |
165 | there, it is subsequently searched in the same directory as the | |
166 | image file or in the immediate parent of the root directory of | |
167 | the container. In this case, if the file is found, its settings | |
168 | will be also read and used, but potentially unsafe settings | |
169 | are ignored. Note that in both these cases, settings on the | |
170 | command line take precedence over the corresponding settings | |
171 | from loaded <filename>.nspawn</filename> files, if both are | |
172 | specified. Unsafe settings are considered all settings that | |
173 | elevate the container's privileges or grant access to | |
174 | additional resources such as files or directories of the | |
175 | host. For details about the format and contents of | |
176 | <filename>.nspawn</filename> files, consult | |
177 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> | |
178 | ||
179 | <para>If this option is set to <option>override</option>, the | |
180 | file is searched, read and used the same way, however, the order of | |
181 | precedence is reversed: settings read from the | |
182 | <filename>.nspawn</filename> file will take precedence over | |
183 | the corresponding command line options, if both are | |
184 | specified.</para> | |
185 | ||
186 | <para>If this option is set to <option>trusted</option>, the | |
187 | file is searched, read and used the same way, but regardless | |
188 | of being found in <filename>/etc/systemd/nspawn/</filename>, | |
189 | <filename>/run/systemd/nspawn/</filename> or next to the image | |
190 | file or container root directory, all settings will take | |
191 | effect, however, command line arguments still take precedence | |
192 | over corresponding settings.</para> | |
193 | ||
194 | <para>If disabled, no <filename>.nspawn</filename> file is read | |
195 | and no settings except the ones on the command line are in | |
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196 | effect.</para> |
197 | ||
198 | <xi:include href="version-info.xml" xpointer="v226"/></listitem> | |
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199 | </varlistentry> |
200 | ||
201 | </variablelist> | |
202 | ||
203 | <refsect2> | |
204 | <title>Image Options</title> | |
205 | ||
206 | <variablelist> | |
207 | ||
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208 | <varlistentry> |
209 | <term><option>-D</option></term> | |
210 | <term><option>--directory=</option></term> | |
211 | ||
212 | <listitem><para>Directory to use as file system root for the | |
213 | container.</para> | |
214 | ||
215 | <para>If neither <option>--directory=</option>, nor | |
216 | <option>--image=</option> is specified the directory is | |
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217 | determined by searching for a directory named the same as the |
218 | machine name specified with <option>--machine=</option>. See | |
219 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
220 | section "Files and Directories" for the precise search path.</para> | |
221 | ||
222 | <para>If neither <option>--directory=</option>, | |
223 | <option>--image=</option>, nor <option>--machine=</option> | |
224 | are specified, the current directory will | |
225 | be used. May not be specified together with | |
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226 | <option>--image=</option>.</para></listitem> |
227 | </varlistentry> | |
228 | ||
229 | <varlistentry> | |
230 | <term><option>--template=</option></term> | |
231 | ||
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232 | <listitem><para>Directory or <literal>btrfs</literal> subvolume to use as template for the |
233 | container's root directory. If this is specified and the container's root directory (as configured by | |
234 | <option>--directory=</option>) does not yet exist it is created as <literal>btrfs</literal> snapshot | |
235 | (if supported) or plain directory (otherwise) and populated from this template tree. Ideally, the | |
236 | specified template path refers to the root of a <literal>btrfs</literal> subvolume, in which case a | |
237 | simple copy-on-write snapshot is taken, and populating the root directory is instant. If the | |
238 | specified template path does not refer to the root of a <literal>btrfs</literal> subvolume (or not | |
239 | even to a <literal>btrfs</literal> file system at all), the tree is copied (though possibly in a | |
240 | 'reflink' copy-on-write scheme — if the file system supports that), which can be substantially more | |
241 | time-consuming. Note that the snapshot taken is of the specified directory or subvolume, including | |
242 | all subdirectories and subvolumes below it, but excluding any sub-mounts. May not be specified | |
243 | together with <option>--image=</option> or <option>--ephemeral</option>.</para> | |
3fe22bb4 | 244 | |
38b38500 | 245 | <para>Note that this switch leaves hostname, machine ID and |
3fe22bb4 | 246 | all other settings that could identify the instance |
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247 | unmodified.</para> |
248 | ||
249 | <xi:include href="version-info.xml" xpointer="v219"/></listitem> | |
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250 | </varlistentry> |
251 | ||
252 | <varlistentry> | |
253 | <term><option>-x</option></term> | |
254 | <term><option>--ephemeral</option></term> | |
255 | ||
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256 | <listitem><para>If specified, the container is run with a temporary snapshot of its file system that is removed |
257 | immediately when the container terminates. May not be specified together with | |
3fe22bb4 | 258 | <option>--template=</option>.</para> |
38b38500 | 259 | <para>Note that this switch leaves hostname, machine ID and all other settings that could identify |
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260 | the instance unmodified. Please note that — as with <option>--template=</option> — taking the |
261 | temporary snapshot is more efficient on file systems that support subvolume snapshots or 'reflinks' | |
262 | natively (<literal>btrfs</literal> or new <literal>xfs</literal>) than on more traditional file | |
263 | systems that do not (<literal>ext4</literal>). Note that the snapshot taken is of the specified | |
264 | directory or subvolume, including all subdirectories and subvolumes below it, but excluding any | |
265 | sub-mounts.</para> | |
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266 | |
267 | <para>With this option no modifications of the container image are retained. Use | |
268 | <option>--volatile=</option> (described below) for other mechanisms to restrict persistency of | |
269 | container images during runtime.</para> | |
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270 | |
271 | <xi:include href="version-info.xml" xpointer="v219"/> | |
b23f1628 | 272 | </listitem> |
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273 | </varlistentry> |
274 | ||
275 | <varlistentry> | |
276 | <term><option>-i</option></term> | |
277 | <term><option>--image=</option></term> | |
278 | ||
279 | <listitem><para>Disk image to mount the root directory for the | |
280 | container from. Takes a path to a regular file or to a block | |
281 | device node. The file or block device must contain | |
282 | either:</para> | |
283 | ||
284 | <itemizedlist> | |
285 | <listitem><para>An MBR partition table with a single | |
286 | partition of type 0x83 that is marked | |
287 | bootable.</para></listitem> | |
288 | ||
289 | <listitem><para>A GUID partition table (GPT) with a single | |
290 | partition of type | |
291 | 0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem> | |
292 | ||
293 | <listitem><para>A GUID partition table (GPT) with a marked | |
294 | root partition which is mounted as the root directory of the | |
295 | container. Optionally, GPT images may contain a home and/or | |
296 | a server data partition which are mounted to the appropriate | |
297 | places in the container. All these partitions must be | |
298 | identified by the partition types defined by the <ulink | |
db811444 | 299 | url="https://uapi-group.org/specifications/specs/discoverable_partitions_specification">Discoverable |
798d3a52 | 300 | Partitions Specification</ulink>.</para></listitem> |
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301 | |
302 | <listitem><para>No partition table, and a single file system spanning the whole image.</para></listitem> | |
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303 | </itemizedlist> |
304 | ||
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305 | <para>On GPT images, if an EFI System Partition (ESP) is discovered, it is automatically mounted to |
306 | <filename>/efi</filename> (or <filename>/boot</filename> as fallback) in case a directory by this name exists | |
307 | and is empty.</para> | |
308 | ||
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309 | <para>Partitions encrypted with LUKS are automatically decrypted. Also, on GPT images dm-verity data integrity |
310 | hash partitions are set up if the root hash for them is specified using the <option>--root-hash=</option> | |
311 | option.</para> | |
312 | ||
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313 | <para>Single file system images (i.e. file systems without a surrounding partition table) can be opened using |
314 | dm-verity if the integrity data is passed using the <option>--root-hash=</option> and | |
c2923fdc | 315 | <option>--verity-data=</option> (and optionally <option>--root-hash-sig=</option>) options.</para> |
e7cbe5cb | 316 | |
0f3be6ca | 317 | <para>Any other partitions, such as foreign partitions or swap partitions are not mounted. May not be specified |
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318 | together with <option>--directory=</option>, <option>--template=</option>.</para> |
319 | ||
320 | <xi:include href="version-info.xml" xpointer="v211"/></listitem> | |
798d3a52 | 321 | </varlistentry> |
58abb66f | 322 | |
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323 | <varlistentry> |
324 | <term><option>--image-policy=<replaceable>policy</replaceable></option></term> | |
325 | ||
326 | <listitem><para>Takes an image policy string as argument, as per | |
327 | <citerefentry><refentrytitle>systemd.image-policy</refentrytitle><manvolnum>7</manvolnum></citerefentry>. The | |
328 | policy is enforced when operating on the disk image specified via <option>--image=</option>, see | |
329 | above. If not specified defaults to | |
330 | <literal>root=verity+signed+encrypted+unprotected+absent:usr=verity+signed+encrypted+unprotected+absent:home=encrypted+unprotected+absent:srv=encrypted+unprotected+absent:esp=unprotected+absent:xbootldr=unprotected+absent:tmp=encrypted+unprotected+absent:var=encrypted+unprotected+absent</literal>, | |
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331 | i.e. all recognized file systems in the image are used, but not the swap partition.</para> |
332 | ||
333 | <xi:include href="version-info.xml" xpointer="v254"/></listitem> | |
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334 | </varlistentry> |
335 | ||
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336 | <varlistentry> |
337 | <term><option>--oci-bundle=</option></term> | |
338 | ||
339 | <listitem><para>Takes the path to an OCI runtime bundle to invoke, as specified in the <ulink | |
340 | url="https://github.com/opencontainers/runtime-spec/blob/master/spec.md">OCI Runtime Specification</ulink>. In | |
341 | this case no <filename>.nspawn</filename> file is loaded, and the root directory and various settings are read | |
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342 | from the OCI runtime JSON data (but data passed on the command line takes precedence).</para> |
343 | ||
344 | <xi:include href="version-info.xml" xpointer="v242"/></listitem> | |
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345 | </varlistentry> |
346 | ||
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347 | <varlistentry> |
348 | <term><option>--read-only</option></term> | |
349 | ||
350 | <listitem><para>Mount the container's root file system (and any other file systems container in the container | |
351 | image) read-only. This has no effect on additional mounts made with <option>--bind=</option>, | |
352 | <option>--tmpfs=</option> and similar options. This mode is implied if the container image file or directory is | |
353 | marked read-only itself. It is also implied if <option>--volatile=</option> is used. In this case the container | |
354 | image on disk is strictly read-only, while changes are permitted but kept non-persistently in memory only. For | |
355 | further details, see below.</para></listitem> | |
356 | </varlistentry> | |
357 | ||
358 | <varlistentry> | |
359 | <term><option>--volatile</option></term> | |
360 | <term><option>--volatile=</option><replaceable>MODE</replaceable></term> | |
361 | ||
362 | <listitem><para>Boots the container in volatile mode. When no mode parameter is passed or when mode is | |
363 | specified as <option>yes</option>, full volatile mode is enabled. This means the root directory is mounted as a | |
364 | mostly unpopulated <literal>tmpfs</literal> instance, and <filename>/usr/</filename> from the OS tree is | |
365 | mounted into it in read-only mode (the system thus starts up with read-only OS image, but pristine state and | |
366 | configuration, any changes are lost on shutdown). When the mode parameter is specified as | |
367 | <option>state</option>, the OS tree is mounted read-only, but <filename>/var/</filename> is mounted as a | |
368 | writable <literal>tmpfs</literal> instance into it (the system thus starts up with read-only OS resources and | |
369 | configuration, but pristine state, and any changes to the latter are lost on shutdown). When the mode parameter | |
370 | is specified as <option>overlay</option> the read-only root file system is combined with a writable | |
371 | <filename>tmpfs</filename> instance through <literal>overlayfs</literal>, so that it appears at it normally | |
372 | would, but any changes are applied to the temporary file system only and lost when the container is | |
373 | terminated. When the mode parameter is specified as <option>no</option> (the default), the whole OS tree is | |
374 | made available writable (unless <option>--read-only</option> is specified, see above).</para> | |
375 | ||
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376 | <para>Note that if one of the volatile modes is chosen, its effect is limited to the root file system |
377 | (or <filename>/var/</filename> in case of <option>state</option>), and any other mounts placed in the | |
378 | hierarchy are unaffected — regardless if they are established automatically (e.g. the EFI system | |
379 | partition that might be mounted to <filename>/efi/</filename> or <filename>/boot/</filename>) or | |
380 | explicitly (e.g. through an additional command line option such as <option>--bind=</option>, see | |
381 | below). This means, even if <option>--volatile=overlay</option> is used changes to | |
382 | <filename>/efi/</filename> or <filename>/boot/</filename> are prohibited in case such a partition | |
383 | exists in the container image operated on, and even if <option>--volatile=state</option> is used the | |
384 | hypothetical file <filename index="false">/etc/foobar</filename> is potentially writable if | |
385 | <option>--bind=/etc/foobar</option> if used to mount it from outside the read-only container | |
3b121157 | 386 | <filename>/etc/</filename> directory.</para> |
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387 | |
388 | <para>The <option>--ephemeral</option> option is closely related to this setting, and provides similar | |
389 | behaviour by making a temporary, ephemeral copy of the whole OS image and executing that. For further details, | |
390 | see above.</para> | |
391 | ||
392 | <para>The <option>--tmpfs=</option> and <option>--overlay=</option> options provide similar functionality, but | |
393 | for specific sub-directories of the OS image only. For details, see below.</para> | |
394 | ||
395 | <para>This option provides similar functionality for containers as the <literal>systemd.volatile=</literal> | |
396 | kernel command line switch provides for host systems. See | |
397 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry> for | |
398 | details.</para> | |
399 | ||
2e542f4e LP |
400 | <para>Note that setting this option to <option>yes</option> or <option>state</option> will only work |
401 | correctly with operating systems in the container that can boot up with only | |
402 | <filename>/usr/</filename> mounted, and are able to automatically populate <filename>/var/</filename> | |
403 | (and <filename>/etc/</filename> in case of <literal>--volatile=yes</literal>). Specifically, this | |
404 | means that operating systems that follow the historic split of <filename>/bin/</filename> and | |
405 | <filename>/lib/</filename> (and related directories) from <filename>/usr/</filename> (i.e. where the | |
406 | former are not symlinks into the latter) are not supported by <literal>--volatile=yes</literal> as | |
407 | container payload. The <option>overlay</option> option does not require any particular preparations | |
408 | in the OS, but do note that <literal>overlayfs</literal> behaviour differs from regular file systems | |
aefdc112 AK |
409 | in a number of ways, and hence compatibility is limited.</para> |
410 | ||
411 | <xi:include href="version-info.xml" xpointer="v216"/></listitem> | |
d99058c9 LP |
412 | </varlistentry> |
413 | ||
58abb66f LP |
414 | <varlistentry> |
415 | <term><option>--root-hash=</option></term> | |
416 | ||
417 | <listitem><para>Takes a data integrity (dm-verity) root hash specified in hexadecimal. This option enables data | |
418 | integrity checks using dm-verity, if the used image contains the appropriate integrity data (see above). The | |
ef3116b5 | 419 | specified hash must match the root hash of integrity data, and is usually at least 256 bits (and hence 64 |
41488e1f LP |
420 | formatted hexadecimal characters) long (in case of SHA256 for example). If this option is not specified, but |
421 | the image file carries the <literal>user.verity.roothash</literal> extended file attribute (see <citerefentry | |
422 | project='man-pages'><refentrytitle>xattr</refentrytitle><manvolnum>7</manvolnum></citerefentry>), then the root | |
423 | hash is read from it, also as formatted hexadecimal characters. If the extended file attribute is not found (or | |
ef3116b5 | 424 | is not supported by the underlying file system), but a file with the <filename>.roothash</filename> suffix is |
e7cbe5cb LB |
425 | found next to the image file, bearing otherwise the same name (except if the image has the |
426 | <filename>.raw</filename> suffix, in which case the root hash file must not have it in its name), the root hash | |
329cde79 LP |
427 | is read from it and automatically used, also as formatted hexadecimal characters.</para> |
428 | ||
429 | <para>Note that this configures the root hash for the root file system. Disk images may also contain | |
430 | separate file systems for the <filename>/usr/</filename> hierarchy, which may be Verity protected as | |
431 | well. The root hash for this protection may be configured via the | |
432 | <literal>user.verity.usrhash</literal> extended file attribute or via a <filename>.usrhash</filename> | |
433 | file adjacent to the disk image, following the same format and logic as for the root hash for the | |
434 | root file system described here. Note that there's currently no switch to configure the root hash for | |
9e7600cf ZJS |
435 | the <filename>/usr/</filename> from the command line.</para> |
436 | ||
437 | <para>Also see the <varname>RootHash=</varname> option in | |
438 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> | |
aefdc112 AK |
439 | |
440 | <xi:include href="version-info.xml" xpointer="v233"/> | |
9e7600cf | 441 | </listitem> |
e7cbe5cb LB |
442 | </varlistentry> |
443 | ||
c2923fdc LB |
444 | <varlistentry> |
445 | <term><option>--root-hash-sig=</option></term> | |
446 | ||
9e7600cf ZJS |
447 | <listitem><para>Takes a PKCS7 signature of the <option>--root-hash=</option> option. |
448 | The semantics are the same as for the <varname>RootHashSignature=</varname> option, see | |
449 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
ec07c3c8 AK |
450 | </para> |
451 | ||
452 | <xi:include href="version-info.xml" xpointer="v246"/></listitem> | |
c2923fdc LB |
453 | </varlistentry> |
454 | ||
e7cbe5cb LB |
455 | <varlistentry> |
456 | <term><option>--verity-data=</option></term> | |
457 | ||
458 | <listitem><para>Takes the path to a data integrity (dm-verity) file. This option enables data integrity checks | |
fe0bdcac | 459 | using dm-verity, if a root-hash is passed and if the used image itself does not contain the integrity data. |
e7cbe5cb LB |
460 | The integrity data must be matched by the root hash. If this option is not specified, but a file with the |
461 | <filename>.verity</filename> suffix is found next to the image file, bearing otherwise the same name (except if | |
462 | the image has the <filename>.raw</filename> suffix, in which case the verity data file must not have it in its name), | |
ec07c3c8 AK |
463 | the verity data is read from it and automatically used.</para> |
464 | ||
465 | <xi:include href="version-info.xml" xpointer="v246"/></listitem> | |
58abb66f | 466 | </varlistentry> |
798d3a52 | 467 | |
d99058c9 LP |
468 | <varlistentry> |
469 | <term><option>--pivot-root=</option></term> | |
470 | ||
471 | <listitem><para>Pivot the specified directory to <filename>/</filename> inside the container, and either unmount the | |
472 | container's old root, or pivot it to another specified directory. Takes one of: a path argument — in which case the | |
473 | specified path will be pivoted to <filename>/</filename> and the old root will be unmounted; or a colon-separated pair | |
474 | of new root path and pivot destination for the old root. The new root path will be pivoted to <filename>/</filename>, | |
475 | and the old <filename>/</filename> will be pivoted to the other directory. Both paths must be absolute, and are resolved | |
476 | in the container's file system namespace.</para> | |
477 | ||
478 | <para>This is for containers which have several bootable directories in them; for example, several | |
b66a6e1a ZJS |
479 | <ulink url="https://ostree.readthedocs.io/en/latest/">OSTree</ulink> deployments. It emulates the |
480 | behavior of the boot loader and the initrd which normally select which directory to mount as the root | |
aefdc112 AK |
481 | and start the container's PID 1 in.</para> |
482 | ||
483 | <xi:include href="version-info.xml" xpointer="v233"/></listitem> | |
d99058c9 LP |
484 | </varlistentry> |
485 | </variablelist> | |
486 | ||
487 | </refsect2><refsect2> | |
488 | <title>Execution Options</title> | |
489 | ||
490 | <variablelist> | |
7732f92b LP |
491 | <varlistentry> |
492 | <term><option>-a</option></term> | |
493 | <term><option>--as-pid2</option></term> | |
494 | ||
495 | <listitem><para>Invoke the shell or specified program as process ID (PID) 2 instead of PID 1 (init). By | |
3f2d1365 AJ |
496 | default, if neither this option nor <option>--boot</option> is used, the selected program is run as the process |
497 | with PID 1, a mode only suitable for programs that are aware of the special semantics that the process with | |
498 | PID 1 has on UNIX. For example, it needs to reap all processes reparented to it, and should implement | |
7732f92b LP |
499 | <command>sysvinit</command> compatible signal handling (specifically: it needs to reboot on SIGINT, reexecute |
500 | on SIGTERM, reload configuration on SIGHUP, and so on). With <option>--as-pid2</option> a minimal stub init | |
3f2d1365 | 501 | process is run as PID 1 and the selected program is executed as PID 2 (and hence does not need to implement any |
7732f92b LP |
502 | special semantics). The stub init process will reap processes as necessary and react appropriately to |
503 | signals. It is recommended to use this mode to invoke arbitrary commands in containers, unless they have been | |
504 | modified to run correctly as PID 1. Or in other words: this switch should be used for pretty much all commands, | |
505 | except when the command refers to an init or shell implementation, as these are generally capable of running | |
a6b5216c | 506 | correctly as PID 1. This option may not be combined with <option>--boot</option>.</para> |
aefdc112 AK |
507 | |
508 | <xi:include href="version-info.xml" xpointer="v229"/> | |
7732f92b LP |
509 | </listitem> |
510 | </varlistentry> | |
511 | ||
798d3a52 ZJS |
512 | <varlistentry> |
513 | <term><option>-b</option></term> | |
514 | <term><option>--boot</option></term> | |
515 | ||
3f2d1365 | 516 | <listitem><para>Automatically search for an init program and invoke it as PID 1, instead of a shell or a user |
7732f92b | 517 | supplied program. If this option is used, arguments specified on the command line are used as arguments for the |
3f2d1365 | 518 | init program. This option may not be combined with <option>--as-pid2</option>.</para> |
7732f92b LP |
519 | |
520 | <para>The following table explains the different modes of invocation and relationship to | |
521 | <option>--as-pid2</option> (see above):</para> | |
522 | ||
523 | <table> | |
524 | <title>Invocation Mode</title> | |
525 | <tgroup cols='2' align='left' colsep='1' rowsep='1'> | |
526 | <colspec colname="switch" /> | |
527 | <colspec colname="explanation" /> | |
528 | <thead> | |
529 | <row> | |
530 | <entry>Switch</entry> | |
531 | <entry>Explanation</entry> | |
532 | </row> | |
533 | </thead> | |
534 | <tbody> | |
535 | <row> | |
536 | <entry>Neither <option>--as-pid2</option> nor <option>--boot</option> specified</entry> | |
4447e799 | 537 | <entry>The passed parameters are interpreted as the command line, which is executed as PID 1 in the container.</entry> |
7732f92b LP |
538 | </row> |
539 | ||
540 | <row> | |
541 | <entry><option>--as-pid2</option> specified</entry> | |
4447e799 | 542 | <entry>The passed parameters are interpreted as the command line, which is executed as PID 2 in the container. A stub init process is run as PID 1.</entry> |
7732f92b LP |
543 | </row> |
544 | ||
545 | <row> | |
546 | <entry><option>--boot</option> specified</entry> | |
3f2d1365 | 547 | <entry>An init program is automatically searched for and run as PID 1 in the container. The passed parameters are used as invocation parameters for this process.</entry> |
7732f92b LP |
548 | </row> |
549 | ||
550 | </tbody> | |
551 | </tgroup> | |
552 | </table> | |
b09c0bba LP |
553 | |
554 | <para>Note that <option>--boot</option> is the default mode of operation if the | |
555 | <filename>systemd-nspawn@.service</filename> template unit file is used.</para> | |
7732f92b | 556 | </listitem> |
798d3a52 ZJS |
557 | </varlistentry> |
558 | ||
5f932eb9 LP |
559 | <varlistentry> |
560 | <term><option>--chdir=</option></term> | |
561 | ||
562 | <listitem><para>Change to the specified working directory before invoking the process in the container. Expects | |
aefdc112 AK |
563 | an absolute path in the container's file system namespace.</para> |
564 | ||
565 | <xi:include href="version-info.xml" xpointer="v229"/></listitem> | |
5f932eb9 LP |
566 | </varlistentry> |
567 | ||
b53ede69 | 568 | <varlistentry> |
0d2a0179 ZJS |
569 | <term><option>-E <replaceable>NAME</replaceable>[=<replaceable>VALUE</replaceable>]</option></term> |
570 | <term><option>--setenv=<replaceable>NAME</replaceable>[=<replaceable>VALUE</replaceable>]</option></term> | |
571 | ||
572 | <listitem><para>Specifies an environment variable to pass to the init process in the container. This | |
573 | may be used to override the default variables or to set additional variables. It may be used more | |
574 | than once to set multiple variables. When <literal>=</literal> and <replaceable>VALUE</replaceable> | |
575 | are omitted, the value of the variable with the same name in the program environment will be used. | |
ec07c3c8 AK |
576 | </para> |
577 | ||
aefdc112 | 578 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> |
b53ede69 PW |
579 | </varlistentry> |
580 | ||
798d3a52 ZJS |
581 | <varlistentry> |
582 | <term><option>-u</option></term> | |
583 | <term><option>--user=</option></term> | |
584 | ||
e9dd6984 ZJS |
585 | <listitem><para>After transitioning into the container, change to the specified user defined in the |
586 | container's user database. Like all other systemd-nspawn features, this is not a security feature and | |
587 | provides protection against accidental destructive operations only.</para></listitem> | |
798d3a52 ZJS |
588 | </varlistentry> |
589 | ||
d99058c9 LP |
590 | <varlistentry> |
591 | <term><option>--kill-signal=</option></term> | |
592 | ||
593 | <listitem><para>Specify the process signal to send to the container's PID 1 when nspawn itself receives | |
594 | <constant>SIGTERM</constant>, in order to trigger an orderly shutdown of the container. Defaults to | |
595 | <constant>SIGRTMIN+3</constant> if <option>--boot</option> is used (on systemd-compatible init systems | |
596 | <constant>SIGRTMIN+3</constant> triggers an orderly shutdown). If <option>--boot</option> is not used and this | |
597 | option is not specified the container's processes are terminated abruptly via <constant>SIGKILL</constant>. For | |
598 | a list of valid signals, see <citerefentry | |
aefdc112 AK |
599 | project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> |
600 | ||
601 | <xi:include href="version-info.xml" xpointer="v220"/></listitem> | |
d99058c9 LP |
602 | </varlistentry> |
603 | ||
604 | <varlistentry> | |
605 | <term><option>--notify-ready=</option></term> | |
606 | ||
607 | <listitem><para>Configures support for notifications from the container's init process. | |
608 | <option>--notify-ready=</option> takes a boolean (<option>no</option> and <option>yes</option>). | |
609 | With option <option>no</option> systemd-nspawn notifies systemd | |
610 | with a <literal>READY=1</literal> message when the init process is created. | |
611 | With option <option>yes</option> systemd-nspawn waits for the | |
612 | <literal>READY=1</literal> message from the init process in the container | |
613 | before sending its own to systemd. For more details about notifications | |
aefdc112 AK |
614 | see <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> |
615 | ||
616 | <xi:include href="version-info.xml" xpointer="v231"/></listitem> | |
d99058c9 | 617 | </varlistentry> |
4a4654e0 LP |
618 | |
619 | <varlistentry> | |
620 | <term><option>--suppress-sync=</option></term> | |
621 | ||
622 | <listitem><para>Expects a boolean argument. If true, turns off any form of on-disk file system | |
623 | synchronization for the container payload. This means all system calls such as <citerefentry | |
624 | project='man-pages'><refentrytitle>sync</refentrytitle><manvolnum>2</manvolnum></citerefentry>, | |
625 | <function>fsync()</function>, <function>syncfs()</function>, … will execute no operation, and the | |
626 | <constant>O_SYNC</constant>/<constant>O_DSYNC</constant> flags to <citerefentry | |
627 | project='man-pages'><refentrytitle>open</refentrytitle><manvolnum>2</manvolnum></citerefentry> and | |
628 | related calls will be made unavailable. This is potentially dangerous, as assumed data integrity | |
629 | guarantees to the container payload are not actually enforced (i.e. data assumed to have been written | |
630 | to disk might be lost if the system is shut down abnormally). However, this can dramatically improve | |
631 | container runtime performance – as long as these guarantees are not required or desirable, for | |
632 | example because any data written by the container is of temporary, redundant nature, or just an | |
633 | intermediary artifact that will be further processed and finalized by a later step in a | |
ec07c3c8 AK |
634 | pipeline. Defaults to false.</para> |
635 | ||
636 | <xi:include href="version-info.xml" xpointer="v250"/></listitem> | |
4a4654e0 | 637 | </varlistentry> |
d99058c9 LP |
638 | </variablelist> |
639 | ||
640 | </refsect2><refsect2> | |
641 | <title>System Identity Options</title> | |
642 | ||
643 | <variablelist> | |
798d3a52 ZJS |
644 | <varlistentry> |
645 | <term><option>-M</option></term> | |
646 | <term><option>--machine=</option></term> | |
647 | ||
648 | <listitem><para>Sets the machine name for this container. This | |
649 | name may be used to identify this container during its runtime | |
650 | (for example in tools like | |
651 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
652 | and similar), and is used to initialize the container's | |
653 | hostname (which the container can choose to override, | |
654 | however). If not specified, the last component of the root | |
655 | directory path of the container is used, possibly suffixed | |
656 | with a random identifier in case <option>--ephemeral</option> | |
657 | mode is selected. If the root directory selected is the host's | |
658 | root directory the host's hostname is used as default | |
aefdc112 AK |
659 | instead.</para> |
660 | ||
661 | <xi:include href="version-info.xml" xpointer="v202"/></listitem> | |
798d3a52 ZJS |
662 | </varlistentry> |
663 | ||
3a9530e5 LP |
664 | <varlistentry> |
665 | <term><option>--hostname=</option></term> | |
666 | ||
667 | <listitem><para>Controls the hostname to set within the container, if different from the machine name. Expects | |
668 | a valid hostname as argument. If this option is used, the kernel hostname of the container will be set to this | |
669 | value, otherwise it will be initialized to the machine name as controlled by the <option>--machine=</option> | |
670 | option described above. The machine name is used for various aspect of identification of the container from the | |
671 | outside, the kernel hostname configurable with this option is useful for the container to identify itself from | |
672 | the inside. It is usually a good idea to keep both forms of identification synchronized, in order to avoid | |
673 | confusion. It is hence recommended to avoid usage of this option, and use <option>--machine=</option> | |
674 | exclusively. Note that regardless whether the container's hostname is initialized from the name set with | |
675 | <option>--hostname=</option> or the one set with <option>--machine=</option>, the container can later override | |
676 | its kernel hostname freely on its own as well.</para> | |
aefdc112 AK |
677 | |
678 | <xi:include href="version-info.xml" xpointer="v239"/> | |
3a9530e5 LP |
679 | </listitem> |
680 | </varlistentry> | |
681 | ||
798d3a52 ZJS |
682 | <varlistentry> |
683 | <term><option>--uuid=</option></term> | |
684 | ||
685 | <listitem><para>Set the specified UUID for the container. The | |
686 | init system will initialize | |
687 | <filename>/etc/machine-id</filename> from this if this file is | |
e01ff70a MS |
688 | not set yet. Note that this option takes effect only if |
689 | <filename>/etc/machine-id</filename> in the container is | |
690 | unpopulated.</para></listitem> | |
798d3a52 | 691 | </varlistentry> |
d99058c9 | 692 | </variablelist> |
798d3a52 | 693 | |
d99058c9 LP |
694 | </refsect2><refsect2> |
695 | <title>Property Options</title> | |
696 | ||
697 | <variablelist> | |
798d3a52 | 698 | <varlistentry> |
4deb5503 | 699 | <term><option>-S</option></term> |
798d3a52 ZJS |
700 | <term><option>--slice=</option></term> |
701 | ||
cd2dfc6f LP |
702 | <listitem><para>Make the container part of the specified slice, instead of the default |
703 | <filename>machine.slice</filename>. This applies only if the machine is run in its own scope unit, i.e. if | |
704 | <option>--keep-unit</option> isn't used.</para> | |
aefdc112 AK |
705 | |
706 | <xi:include href="version-info.xml" xpointer="v206"/> | |
f36933fe LP |
707 | </listitem> |
708 | </varlistentry> | |
709 | ||
710 | <varlistentry> | |
711 | <term><option>--property=</option></term> | |
712 | ||
cd2dfc6f LP |
713 | <listitem><para>Set a unit property on the scope unit to register for the machine. This applies only if the |
714 | machine is run in its own scope unit, i.e. if <option>--keep-unit</option> isn't used. Takes unit property | |
715 | assignments in the same format as <command>systemctl set-property</command>. This is useful to set memory | |
15102ced | 716 | limits and similar for the container.</para> |
aefdc112 AK |
717 | |
718 | <xi:include href="version-info.xml" xpointer="v220"/> | |
798d3a52 ZJS |
719 | </listitem> |
720 | </varlistentry> | |
721 | ||
d99058c9 LP |
722 | <varlistentry> |
723 | <term><option>--register=</option></term> | |
724 | ||
725 | <listitem><para>Controls whether the container is registered with | |
726 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Takes a | |
727 | boolean argument, which defaults to <literal>yes</literal>. This option should be enabled when the container | |
728 | runs a full Operating System (more specifically: a system and service manager as PID 1), and is useful to | |
729 | ensure that the container is accessible via | |
730 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> and shown by | |
731 | tools such as <citerefentry | |
732 | project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. If the container | |
733 | does not run a service manager, it is recommended to set this option to | |
aefdc112 AK |
734 | <literal>no</literal>.</para> |
735 | ||
736 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
d99058c9 LP |
737 | </varlistentry> |
738 | ||
739 | <varlistentry> | |
740 | <term><option>--keep-unit</option></term> | |
741 | ||
742 | <listitem><para>Instead of creating a transient scope unit to run the container in, simply use the service or | |
743 | scope unit <command>systemd-nspawn</command> has been invoked in. If <option>--register=yes</option> is set | |
744 | this unit is registered with | |
745 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This | |
746 | switch should be used if <command>systemd-nspawn</command> is invoked from within a service unit, and the | |
747 | service unit's sole purpose is to run a single <command>systemd-nspawn</command> container. This option is not | |
748 | available if run from a user session.</para> | |
749 | <para>Note that passing <option>--keep-unit</option> disables the effect of <option>--slice=</option> and | |
750 | <option>--property=</option>. Use <option>--keep-unit</option> and <option>--register=no</option> in | |
751 | combination to disable any kind of unit allocation or registration with | |
aefdc112 AK |
752 | <command>systemd-machined</command>.</para> |
753 | ||
754 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
d99058c9 LP |
755 | </varlistentry> |
756 | </variablelist> | |
757 | ||
758 | </refsect2><refsect2> | |
759 | <title>User Namespacing Options</title> | |
760 | ||
761 | <variablelist> | |
03cfe0d5 LP |
762 | <varlistentry> |
763 | <term><option>--private-users=</option></term> | |
764 | ||
d2e5535f LP |
765 | <listitem><para>Controls user namespacing. If enabled, the container will run with its own private set of UNIX |
766 | user and group ids (UIDs and GIDs). This involves mapping the private UIDs/GIDs used in the container (starting | |
767 | with the container's root user 0 and up) to a range of UIDs/GIDs on the host that are not used for other | |
768 | purposes (usually in the range beyond the host's UID/GID 65536). The parameter may be specified as follows:</para> | |
769 | ||
770 | <orderedlist> | |
2dd67817 | 771 | <listitem><para>If one or two colon-separated numbers are specified, user namespacing is turned on. The first |
ae209204 ZJS |
772 | parameter specifies the first host UID/GID to assign to the container, the second parameter specifies the |
773 | number of host UIDs/GIDs to assign to the container. If the second parameter is omitted, 65536 UIDs/GIDs are | |
774 | assigned.</para></listitem> | |
775 | ||
22326f15 LP |
776 | <listitem><para>If the parameter is <literal>yes</literal>, user namespacing is turned on. The |
777 | UID/GID range to use is determined automatically from the file ownership of the root directory of | |
778 | the container's directory tree. To use this option, make sure to prepare the directory tree in | |
779 | advance, and ensure that all files and directories in it are owned by UIDs/GIDs in the range you'd | |
780 | like to use. Also, make sure that used file ACLs exclusively reference UIDs/GIDs in the appropriate | |
781 | range. In this mode, the number of UIDs/GIDs assigned to the container is 65536, and the owner | |
782 | UID/GID of the root directory must be a multiple of 65536.</para></listitem> | |
783 | ||
784 | <listitem><para>If the parameter is <literal>no</literal>, user namespacing is turned off. This is | |
785 | the default.</para> | |
ae209204 ZJS |
786 | </listitem> |
787 | ||
22326f15 LP |
788 | <listitem><para>If the parameter is <literal>identity</literal>, user namespacing is employed with |
789 | an identity mapping for the first 65536 UIDs/GIDs. This is mostly equivalent to | |
790 | <option>--private-users=0:65536</option>. While it does not provide UID/GID isolation, since all | |
791 | host and container UIDs/GIDs are chosen identically it does provide process capability isolation, | |
792 | and hence is often a good choice if proper user namespacing with distinct UID maps is not | |
793 | appropriate.</para></listitem> | |
794 | ||
795 | <listitem><para>The special value <literal>pick</literal> turns on user namespacing. In this case | |
796 | the UID/GID range is automatically chosen. As first step, the file owner UID/GID of the root | |
797 | directory of the container's directory tree is read, and it is checked that no other container is | |
798 | currently using it. If this check is successful, the UID/GID range determined this way is used, | |
15102ced ZJS |
799 | similarly to the behavior if <literal>yes</literal> is specified. If the check is not successful |
800 | (and thus the UID/GID range indicated in the root directory's file owner is already used elsewhere) | |
801 | a new – currently unused – UID/GID range of 65536 UIDs/GIDs is randomly chosen between the host | |
22326f15 LP |
802 | UID/GIDs of 524288 and 1878982656, always starting at a multiple of 65536, and, if possible, |
803 | consistently hashed from the machine name. This setting implies | |
804 | <option>--private-users-ownership=auto</option> (see below), which possibly has the effect that the | |
805 | files and directories in the container's directory tree will be owned by the appropriate users of | |
806 | the range picked. Using this option makes user namespace behavior fully automatic. Note that the | |
807 | first invocation of a previously unused container image might result in picking a new UID/GID range | |
808 | for it, and thus in the (possibly expensive) file ownership adjustment operation. However, | |
809 | subsequent invocations of the container will be cheap (unless of course the picked UID/GID range is | |
810 | assigned to a different use by then).</para></listitem> | |
d2e5535f LP |
811 | </orderedlist> |
812 | ||
813 | <para>It is recommended to assign at least 65536 UIDs/GIDs to each container, so that the usable UID/GID range in the | |
814 | container covers 16 bit. For best security, do not assign overlapping UID/GID ranges to multiple containers. It is | |
815 | hence a good idea to use the upper 16 bit of the host 32-bit UIDs/GIDs as container identifier, while the lower 16 | |
2dd67817 | 816 | bit encode the container UID/GID used. This is in fact the behavior enforced by the |
d2e5535f LP |
817 | <option>--private-users=pick</option> option.</para> |
818 | ||
819 | <para>When user namespaces are used, the GID range assigned to each container is always chosen identical to the | |
820 | UID range.</para> | |
821 | ||
822 | <para>In most cases, using <option>--private-users=pick</option> is the recommended option as it enhances | |
823 | container security massively and operates fully automatically in most cases.</para> | |
824 | ||
825 | <para>Note that the picked UID/GID range is not written to <filename>/etc/passwd</filename> or | |
826 | <filename>/etc/group</filename>. In fact, the allocation of the range is not stored persistently anywhere, | |
aa10469e LP |
827 | except in the file ownership of the files and directories of the container.</para> |
828 | ||
829 | <para>Note that when user namespacing is used file ownership on disk reflects this, and all of the container's | |
830 | files and directories are owned by the container's effective user and group IDs. This means that copying files | |
831 | from and to the container image requires correction of the numeric UID/GID values, according to the UID/GID | |
aefdc112 AK |
832 | shift applied.</para> |
833 | ||
834 | <xi:include href="version-info.xml" xpointer="v220"/></listitem> | |
03cfe0d5 LP |
835 | </varlistentry> |
836 | ||
d2e5535f | 837 | <varlistentry> |
22326f15 LP |
838 | <term><option>--private-users-ownership=</option></term> |
839 | ||
840 | <listitem><para>Controls how to adjust the container image's UIDs and GIDs to match the UID/GID range | |
841 | chosen with <option>--private-users=</option>, see above. Takes one of <literal>off</literal> (to | |
842 | leave the image as is), <literal>chown</literal> (to recursively <function>chown()</function> the | |
843 | container's directory tree as needed), <literal>map</literal> (in order to use transparent ID mapping | |
844 | mounts) or <literal>auto</literal> for automatically using <literal>map</literal> where available and | |
845 | <literal>chown</literal> where not.</para> | |
846 | ||
847 | <para>If <literal>chown</literal> is selected, all files and directories in the container's directory | |
848 | tree will be adjusted so that they are owned by the appropriate UIDs/GIDs selected for the container | |
849 | (see above). This operation is potentially expensive, as it involves iterating through the full | |
850 | directory tree of the container. Besides actual file ownership, file ACLs are adjusted as | |
851 | well.</para> | |
852 | ||
853 | <para>Typically <literal>map</literal> is the best choice, since it transparently maps UIDs/GIDs in | |
854 | memory as needed without modifying the image, and without requiring an expensive recursive adjustment | |
855 | operation. However, it is not available for all file systems, currently.</para> | |
856 | ||
857 | <para>The <option>--private-users-ownership=auto</option> option is implied if | |
858 | <option>--private-users=pick</option> is used. This option has no effect if user namespacing is not | |
ec07c3c8 AK |
859 | used.</para> |
860 | ||
aefdc112 | 861 | <xi:include href="version-info.xml" xpointer="v230"/></listitem> |
d2e5535f | 862 | </varlistentry> |
03cfe0d5 | 863 | |
6265bde2 ZJS |
864 | <varlistentry> |
865 | <term><option>-U</option></term> | |
866 | ||
867 | <listitem><para>If the kernel supports the user namespaces feature, equivalent to | |
22326f15 | 868 | <option>--private-users=pick --private-users-ownership=auto</option>, otherwise equivalent to |
6265bde2 ZJS |
869 | <option>--private-users=no</option>.</para> |
870 | ||
871 | <para>Note that <option>-U</option> is the default if the | |
872 | <filename>systemd-nspawn@.service</filename> template unit file is used.</para> | |
873 | ||
22326f15 | 874 | <para>Note: it is possible to undo the effect of <option>--private-users-ownership=chown</option> (or |
6265bde2 ZJS |
875 | <option>-U</option>) on the file system by redoing the operation with the first UID of 0:</para> |
876 | ||
22326f15 | 877 | <programlisting>systemd-nspawn … --private-users=0 --private-users-ownership=chown</programlisting> |
aefdc112 AK |
878 | |
879 | <xi:include href="version-info.xml" xpointer="v230"/> | |
6265bde2 ZJS |
880 | </listitem> |
881 | </varlistentry> | |
882 | ||
d99058c9 LP |
883 | </variablelist> |
884 | ||
885 | </refsect2><refsect2> | |
886 | <title>Networking Options</title> | |
887 | ||
888 | <variablelist> | |
889 | ||
798d3a52 ZJS |
890 | <varlistentry> |
891 | <term><option>--private-network</option></term> | |
892 | ||
893 | <listitem><para>Disconnect networking of the container from | |
894 | the host. This makes all network interfaces unavailable in the | |
895 | container, with the exception of the loopback device and those | |
896 | specified with <option>--network-interface=</option> and | |
897 | configured with <option>--network-veth</option>. If this | |
ec562515 | 898 | option is specified, the <constant>CAP_NET_ADMIN</constant> capability will be |
798d3a52 | 899 | added to the set of capabilities the container retains. The |
bc96c63c ZJS |
900 | latter may be disabled by using <option>--drop-capability=</option>. |
901 | If this option is not specified (or implied by one of the options | |
902 | listed below), the container will have full access to the host network. | |
903 | </para></listitem> | |
798d3a52 ZJS |
904 | </varlistentry> |
905 | ||
906 | <varlistentry> | |
907 | <term><option>--network-interface=</option></term> | |
908 | ||
2f091b1b TM |
909 | <listitem><para>Assign the specified network interface to the container. Either takes a single |
910 | interface name, referencing the name on the host, or a colon-separated pair of interfaces, in which | |
911 | case the first one references the name on the host, and the second one the name in the container. | |
912 | When the container terminates, the interface is moved back to the calling namespace and renamed to | |
913 | its original name. Note that <option>--network-interface=</option> implies | |
914 | <option>--private-network</option>. This option may be used more than once to add multiple network | |
915 | interfaces to the container.</para> | |
44a8ad7a LP |
916 | |
917 | <para>Note that any network interface specified this way must already exist at the time the container | |
918 | is started. If the container shall be started automatically at boot via a | |
919 | <filename>systemd-nspawn@.service</filename> unit file instance, it might hence make sense to add a | |
920 | unit file drop-in to the service instance | |
921 | (e.g. <filename>/etc/systemd/system/systemd-nspawn@foobar.service.d/50-network.conf</filename>) with | |
922 | contents like the following:</para> | |
923 | ||
924 | <programlisting>[Unit] | |
925 | Wants=sys-subsystem-net-devices-ens1.device | |
926 | After=sys-subsystem-net-devices-ens1.device</programlisting> | |
927 | ||
928 | <para>This will make sure that activation of the container service will be delayed until the | |
929 | <literal>ens1</literal> network interface has shown up. This is required since hardware probing is | |
930 | fully asynchronous, and network interfaces might be discovered only later during the boot process, | |
931 | after the container would normally be started without these explicit dependencies.</para> | |
aefdc112 AK |
932 | |
933 | <xi:include href="version-info.xml" xpointer="v209"/> | |
44a8ad7a | 934 | </listitem> |
798d3a52 ZJS |
935 | </varlistentry> |
936 | ||
937 | <varlistentry> | |
938 | <term><option>--network-macvlan=</option></term> | |
939 | ||
44a8ad7a | 940 | <listitem><para>Create a <literal>macvlan</literal> interface of the specified Ethernet network |
2f091b1b TM |
941 | interface and add it to the container. Either takes a single interface name, referencing the name |
942 | on the host, or a colon-separated pair of interfaces, in which case the first one references the name | |
943 | on the host, and the second one the name in the container. A <literal>macvlan</literal> interface is | |
944 | a virtual interface that adds a second MAC address to an existing physical Ethernet link. If the | |
945 | container interface name is not defined, the interface in the container will be named after the | |
946 | interface on the host, prefixed with <literal>mv-</literal>. Note that | |
44a8ad7a LP |
947 | <option>--network-macvlan=</option> implies <option>--private-network</option>. This option may be |
948 | used more than once to add multiple network interfaces to the container.</para> | |
949 | ||
950 | <para>As with <option>--network-interface=</option>, the underlying Ethernet network interface must | |
951 | already exist at the time the container is started, and thus similar unit file drop-ins as described | |
aefdc112 AK |
952 | above might be useful.</para> |
953 | ||
954 | <xi:include href="version-info.xml" xpointer="v211"/></listitem> | |
798d3a52 ZJS |
955 | </varlistentry> |
956 | ||
957 | <varlistentry> | |
958 | <term><option>--network-ipvlan=</option></term> | |
959 | ||
44a8ad7a | 960 | <listitem><para>Create an <literal>ipvlan</literal> interface of the specified Ethernet network |
2f091b1b TM |
961 | interface and add it to the container. Either takes a single interface name, referencing the name on |
962 | the host, or a colon-separated pair of interfaces, in which case the first one references the name | |
963 | on the host, and the second one the name in the container. An <literal>ipvlan</literal> interface is | |
964 | a virtual interface, | |
44a8ad7a | 965 | similar to a <literal>macvlan</literal> interface, which uses the same MAC address as the underlying |
2f091b1b TM |
966 | interface. If the container interface name is not defined, the interface in the container will be |
967 | named after the interface on the host, prefixed | |
44a8ad7a LP |
968 | with <literal>iv-</literal>. Note that <option>--network-ipvlan=</option> implies |
969 | <option>--private-network</option>. This option may be used more than once to add multiple network | |
970 | interfaces to the container.</para> | |
971 | ||
972 | <para>As with <option>--network-interface=</option>, the underlying Ethernet network interface must | |
973 | already exist at the time the container is started, and thus similar unit file drop-ins as described | |
aefdc112 AK |
974 | above might be useful.</para> |
975 | ||
976 | <xi:include href="version-info.xml" xpointer="v219"/></listitem> | |
798d3a52 ZJS |
977 | </varlistentry> |
978 | ||
979 | <varlistentry> | |
980 | <term><option>-n</option></term> | |
981 | <term><option>--network-veth</option></term> | |
982 | ||
5e7423ff LP |
983 | <listitem><para>Create a virtual Ethernet link (<literal>veth</literal>) between host and container. The host |
984 | side of the Ethernet link will be available as a network interface named after the container's name (as | |
985 | specified with <option>--machine=</option>), prefixed with <literal>ve-</literal>. The container side of the | |
986 | Ethernet link will be named <literal>host0</literal>. The <option>--network-veth</option> option implies | |
987 | <option>--private-network</option>.</para> | |
988 | ||
989 | <para>Note that | |
990 | <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
991 | includes by default a network file <filename>/usr/lib/systemd/network/80-container-ve.network</filename> | |
992 | matching the host-side interfaces created this way, which contains settings to enable automatic address | |
993 | provisioning on the created virtual link via DHCP, as well as automatic IP routing onto the host's external | |
994 | network interfaces. It also contains <filename>/usr/lib/systemd/network/80-container-host0.network</filename> | |
995 | matching the container-side interface created this way, containing settings to enable client side address | |
996 | assignment via DHCP. In case <filename>systemd-networkd</filename> is running on both the host and inside the | |
997 | container, automatic IP communication from the container to the host is thus available, with further | |
998 | connectivity to the external network.</para> | |
b09c0bba LP |
999 | |
1000 | <para>Note that <option>--network-veth</option> is the default if the | |
1001 | <filename>systemd-nspawn@.service</filename> template unit file is used.</para> | |
6cc68362 LP |
1002 | |
1003 | <para>Note that on Linux network interface names may have a length of 15 characters at maximum, while | |
1004 | container names may have a length up to 64 characters. As this option derives the host-side interface | |
1005 | name from the container name the name is possibly truncated. Thus, care needs to be taken to ensure | |
1006 | that interface names remain unique in this case, or even better container names are generally not | |
bc5ea049 KK |
1007 | chosen longer than 12 characters, to avoid the truncation. If the name is truncated, |
1008 | <command>systemd-nspawn</command> will automatically append a 4-digit hash value to the name to | |
1009 | reduce the chance of collisions. However, the hash algorithm is not collision-free. (See | |
1010 | <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
1011 | for details on older naming algorithms for this interface). Alternatively, the | |
6cc68362 LP |
1012 | <option>--network-veth-extra=</option> option may be used, which allows free configuration of the |
1013 | host-side interface name independently of the container name — but might require a bit more | |
1014 | additional configuration in case bridging in a fashion similar to <option>--network-bridge=</option> | |
1015 | is desired.</para> | |
aefdc112 AK |
1016 | |
1017 | <xi:include href="version-info.xml" xpointer="v209"/> | |
5e7423ff | 1018 | </listitem> |
798d3a52 ZJS |
1019 | </varlistentry> |
1020 | ||
f6d6bad1 LP |
1021 | <varlistentry> |
1022 | <term><option>--network-veth-extra=</option></term> | |
1023 | ||
1024 | <listitem><para>Adds an additional virtual Ethernet link | |
1025 | between host and container. Takes a colon-separated pair of | |
1026 | host interface name and container interface name. The latter | |
1027 | may be omitted in which case the container and host sides will | |
1028 | be assigned the same name. This switch is independent of | |
ccddd104 | 1029 | <option>--network-veth</option>, and — in contrast — may be |
f6d6bad1 LP |
1030 | used multiple times, and allows configuration of the network |
1031 | interface names. Note that <option>--network-bridge=</option> | |
1032 | has no effect on interfaces created with | |
aefdc112 AK |
1033 | <option>--network-veth-extra=</option>.</para> |
1034 | ||
1035 | <xi:include href="version-info.xml" xpointer="v228"/></listitem> | |
f6d6bad1 LP |
1036 | </varlistentry> |
1037 | ||
798d3a52 ZJS |
1038 | <varlistentry> |
1039 | <term><option>--network-bridge=</option></term> | |
1040 | ||
6cc68362 LP |
1041 | <listitem><para>Adds the host side of the Ethernet link created with <option>--network-veth</option> |
1042 | to the specified Ethernet bridge interface. Expects a valid network interface name of a bridge device | |
1043 | as argument. Note that <option>--network-bridge=</option> implies <option>--network-veth</option>. If | |
1044 | this option is used, the host side of the Ethernet link will use the <literal>vb-</literal> prefix | |
1045 | instead of <literal>ve-</literal>. Regardless of the used naming prefix the same network interface | |
1046 | name length limits imposed by Linux apply, along with the complications this creates (for details see | |
44a8ad7a LP |
1047 | above).</para> |
1048 | ||
1049 | <para>As with <option>--network-interface=</option>, the underlying bridge network interface must | |
1050 | already exist at the time the container is started, and thus similar unit file drop-ins as described | |
aefdc112 AK |
1051 | above might be useful.</para> |
1052 | ||
1053 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
798d3a52 ZJS |
1054 | </varlistentry> |
1055 | ||
938d2579 LP |
1056 | <varlistentry> |
1057 | <term><option>--network-zone=</option></term> | |
1058 | ||
1059 | <listitem><para>Creates a virtual Ethernet link (<literal>veth</literal>) to the container and adds it to an | |
1060 | automatically managed Ethernet bridge interface. The bridge interface is named after the passed argument, | |
1061 | prefixed with <literal>vz-</literal>. The bridge interface is automatically created when the first container | |
1062 | configured for its name is started, and is automatically removed when the last container configured for its | |
1063 | name exits. Hence, each bridge interface configured this way exists only as long as there's at least one | |
1064 | container referencing it running. This option is very similar to <option>--network-bridge=</option>, besides | |
1065 | this automatic creation/removal of the bridge device.</para> | |
1066 | ||
1067 | <para>This setting makes it easy to place multiple related containers on a common, virtual Ethernet-based | |
1068 | broadcast domain, here called a "zone". Each container may only be part of one zone, but each zone may contain | |
1069 | any number of containers. Each zone is referenced by its name. Names may be chosen freely (as long as they form | |
1070 | valid network interface names when prefixed with <literal>vz-</literal>), and it is sufficient to pass the same | |
cf917c27 | 1071 | name to the <option>--network-zone=</option> switch of the various concurrently running containers to join |
938d2579 LP |
1072 | them in one zone.</para> |
1073 | ||
1074 | <para>Note that | |
1075 | <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1076 | includes by default a network file <filename>/usr/lib/systemd/network/80-container-vz.network</filename> | |
1077 | matching the bridge interfaces created this way, which contains settings to enable automatic address | |
1078 | provisioning on the created virtual network via DHCP, as well as automatic IP routing onto the host's external | |
1079 | network interfaces. Using <option>--network-zone=</option> is hence in most cases fully automatic and | |
1080 | sufficient to connect multiple local containers in a joined broadcast domain to the host, with further | |
1081 | connectivity to the external network.</para> | |
aefdc112 AK |
1082 | |
1083 | <xi:include href="version-info.xml" xpointer="v230"/> | |
938d2579 LP |
1084 | </listitem> |
1085 | </varlistentry> | |
1086 | ||
798d3a52 | 1087 | <varlistentry> |
d99058c9 | 1088 | <term><option>--network-namespace-path=</option></term> |
798d3a52 | 1089 | |
d99058c9 LP |
1090 | <listitem><para>Takes the path to a file representing a kernel |
1091 | network namespace that the container shall run in. The specified path | |
1092 | should refer to a (possibly bind-mounted) network namespace file, as | |
1093 | exposed by the kernel below <filename>/proc/$PID/ns/net</filename>. | |
1094 | This makes the container enter the given network namespace. One of the | |
1095 | typical use cases is to give a network namespace under | |
1096 | <filename>/run/netns</filename> created by <citerefentry | |
1097 | project='man-pages'><refentrytitle>ip-netns</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
1098 | for example, <option>--network-namespace-path=/run/netns/foo</option>. | |
1099 | Note that this option cannot be used together with other | |
1100 | network-related options, such as <option>--private-network</option> | |
aefdc112 AK |
1101 | or <option>--network-interface=</option>.</para> |
1102 | ||
1103 | <xi:include href="version-info.xml" xpointer="v236"/></listitem> | |
d99058c9 LP |
1104 | </varlistentry> |
1105 | ||
1106 | <varlistentry> | |
1107 | <term><option>-p</option></term> | |
1108 | <term><option>--port=</option></term> | |
1109 | ||
1110 | <listitem><para>If private networking is enabled, maps an IP | |
1111 | port on the host onto an IP port on the container. Takes a | |
1112 | protocol specifier (either <literal>tcp</literal> or | |
798d3a52 ZJS |
1113 | <literal>udp</literal>), separated by a colon from a host port |
1114 | number in the range 1 to 65535, separated by a colon from a | |
1115 | container port number in the range from 1 to 65535. The | |
1116 | protocol specifier and its separating colon may be omitted, in | |
1117 | which case <literal>tcp</literal> is assumed. The container | |
7c918141 | 1118 | port number and its colon may be omitted, in which case the |
798d3a52 | 1119 | same port as the host port is implied. This option is only |
a8eaaee7 | 1120 | supported if private networking is used, such as with |
938d2579 | 1121 | <option>--network-veth</option>, <option>--network-zone=</option> |
aefdc112 AK |
1122 | <option>--network-bridge=</option>.</para> |
1123 | ||
1124 | <xi:include href="version-info.xml" xpointer="v219"/></listitem> | |
798d3a52 | 1125 | </varlistentry> |
d99058c9 | 1126 | </variablelist> |
798d3a52 | 1127 | |
d99058c9 LP |
1128 | </refsect2><refsect2> |
1129 | <title>Security Options</title> | |
798d3a52 | 1130 | |
d99058c9 | 1131 | <variablelist> |
798d3a52 ZJS |
1132 | <varlistentry> |
1133 | <term><option>--capability=</option></term> | |
1134 | ||
ec562515 ZJS |
1135 | <listitem><para>List one or more additional capabilities to grant the container. Takes a |
1136 | comma-separated list of capability names, see <citerefentry | |
1137 | project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
a30504ed | 1138 | for more information. Note that the following capabilities will be granted in any way: |
ec562515 ZJS |
1139 | <constant>CAP_AUDIT_CONTROL</constant>, <constant>CAP_AUDIT_WRITE</constant>, |
1140 | <constant>CAP_CHOWN</constant>, <constant>CAP_DAC_OVERRIDE</constant>, | |
1141 | <constant>CAP_DAC_READ_SEARCH</constant>, <constant>CAP_FOWNER</constant>, | |
1142 | <constant>CAP_FSETID</constant>, <constant>CAP_IPC_OWNER</constant>, <constant>CAP_KILL</constant>, | |
1143 | <constant>CAP_LEASE</constant>, <constant>CAP_LINUX_IMMUTABLE</constant>, | |
1144 | <constant>CAP_MKNOD</constant>, <constant>CAP_NET_BIND_SERVICE</constant>, | |
1145 | <constant>CAP_NET_BROADCAST</constant>, <constant>CAP_NET_RAW</constant>, | |
1146 | <constant>CAP_SETFCAP</constant>, <constant>CAP_SETGID</constant>, <constant>CAP_SETPCAP</constant>, | |
1147 | <constant>CAP_SETUID</constant>, <constant>CAP_SYS_ADMIN</constant>, | |
1148 | <constant>CAP_SYS_BOOT</constant>, <constant>CAP_SYS_CHROOT</constant>, | |
1149 | <constant>CAP_SYS_NICE</constant>, <constant>CAP_SYS_PTRACE</constant>, | |
1150 | <constant>CAP_SYS_RESOURCE</constant>, <constant>CAP_SYS_TTY_CONFIG</constant>. Also | |
1151 | <constant>CAP_NET_ADMIN</constant> is retained if <option>--private-network</option> is specified. | |
1152 | If the special value <literal>all</literal> is passed, all capabilities are retained.</para> | |
8a99bd0c ZJS |
1153 | |
1154 | <para>If the special value of <literal>help</literal> is passed, the program will print known | |
88fc9c9b TH |
1155 | capability names and exit.</para> |
1156 | ||
1157 | <para>This option sets the bounding set of capabilities which | |
1158 | also limits the ambient capabilities as given with the | |
aefdc112 AK |
1159 | <option>--ambient-capability=</option>.</para> |
1160 | ||
1161 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1162 | </varlistentry> |
1163 | ||
1164 | <varlistentry> | |
1165 | <term><option>--drop-capability=</option></term> | |
1166 | ||
1167 | <listitem><para>Specify one or more additional capabilities to | |
1168 | drop for the container. This allows running the container with | |
1169 | fewer capabilities than the default (see | |
8a99bd0c ZJS |
1170 | above).</para> |
1171 | ||
1172 | <para>If the special value of <literal>help</literal> is passed, the program will print known | |
88fc9c9b TH |
1173 | capability names and exit.</para> |
1174 | ||
1175 | <para>This option sets the bounding set of capabilities which | |
1176 | also limits the ambient capabilities as given with the | |
aefdc112 AK |
1177 | <option>--ambient-capability=</option>.</para> |
1178 | ||
1179 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
88fc9c9b TH |
1180 | </varlistentry> |
1181 | ||
1182 | <varlistentry> | |
1183 | <term><option>--ambient-capability=</option></term> | |
1184 | ||
1185 | <listitem><para>Specify one or more additional capabilities to | |
1186 | pass in the inheritable and ambient set to the program started | |
1187 | within the container. The value <literal>all</literal> is not | |
1188 | supported for this setting.</para> | |
1189 | ||
1190 | <para>All capabilities specified here must be in the set | |
1191 | allowed with the <option>--capability=</option> and | |
1192 | <option>--drop-capability=</option> options. Otherwise, an | |
1193 | error message will be shown.</para> | |
1194 | ||
1195 | <para>This option cannot be combined with the boot mode of the | |
1196 | container (as requested via <option>--boot</option>).</para> | |
1197 | ||
1198 | <para>If the special value of <literal>help</literal> is | |
1199 | passed, the program will print known capability names and | |
ec07c3c8 AK |
1200 | exit.</para> |
1201 | ||
1202 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
798d3a52 ZJS |
1203 | </varlistentry> |
1204 | ||
66edd963 LP |
1205 | <varlistentry> |
1206 | <term><option>--no-new-privileges=</option></term> | |
1207 | ||
6b000af4 LP |
1208 | <listitem><para>Takes a boolean argument. Specifies the value of the |
1209 | <constant>PR_SET_NO_NEW_PRIVS</constant> flag for the container payload. Defaults to off. When turned | |
1210 | on the payload code of the container cannot acquire new privileges, i.e. the "setuid" file bit as | |
1211 | well as file system capabilities will not have an effect anymore. See <citerefentry | |
1212 | project='man-pages'><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> for | |
aefdc112 AK |
1213 | details about this flag. </para> |
1214 | ||
1215 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
66edd963 LP |
1216 | </varlistentry> |
1217 | ||
960e4569 | 1218 | <varlistentry> |
6b000af4 LP |
1219 | <term><option>--system-call-filter=</option></term> <listitem><para>Alter the system call filter |
1220 | applied to containers. Takes a space-separated list of system call names or group names (the latter | |
1221 | prefixed with <literal>@</literal>, as listed by the <command>syscall-filter</command> command of | |
c7fc3c4c | 1222 | <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>). Passed |
6b000af4 LP |
1223 | system calls will be permitted. The list may optionally be prefixed by <literal>~</literal>, in which |
1224 | case all listed system calls are prohibited. If this command line option is used multiple times the | |
1225 | configured lists are combined. If both a positive and a negative list (that is one system call list | |
1226 | without and one with the <literal>~</literal> prefix) are configured, the negative list takes | |
1227 | precedence over the positive list. Note that <command>systemd-nspawn</command> always implements a | |
1228 | system call allow list (as opposed to a deny list!), and this command line option hence adds or | |
1229 | removes entries from the default allow list, depending on the <literal>~</literal> prefix. Note that | |
1230 | the applied system call filter is also altered implicitly if additional capabilities are passed using | |
aefdc112 AK |
1231 | the <command>--capabilities=</command>.</para> |
1232 | ||
1233 | <xi:include href="version-info.xml" xpointer="v235"/></listitem> | |
960e4569 LP |
1234 | </varlistentry> |
1235 | ||
d99058c9 LP |
1236 | <varlistentry> |
1237 | <term><option>-Z</option></term> | |
1238 | <term><option>--selinux-context=</option></term> | |
1239 | ||
1240 | <listitem><para>Sets the SELinux security context to be used | |
1241 | to label processes in the container.</para> | |
aefdc112 AK |
1242 | |
1243 | <xi:include href="version-info.xml" xpointer="v209"/> | |
d99058c9 LP |
1244 | </listitem> |
1245 | </varlistentry> | |
1246 | ||
1247 | <varlistentry> | |
1248 | <term><option>-L</option></term> | |
1249 | <term><option>--selinux-apifs-context=</option></term> | |
1250 | ||
1251 | <listitem><para>Sets the SELinux security context to be used | |
1252 | to label files in the virtual API file systems in the | |
1253 | container.</para> | |
aefdc112 AK |
1254 | |
1255 | <xi:include href="version-info.xml" xpointer="v209"/> | |
d99058c9 LP |
1256 | </listitem> |
1257 | </varlistentry> | |
1258 | </variablelist> | |
1259 | ||
1260 | </refsect2><refsect2> | |
1261 | <title>Resource Options</title> | |
1262 | ||
1263 | <variablelist> | |
1264 | ||
bf428efb LP |
1265 | <varlistentry> |
1266 | <term><option>--rlimit=</option></term> | |
1267 | ||
1268 | <listitem><para>Sets the specified POSIX resource limit for the container payload. Expects an assignment of the | |
1269 | form | |
1270 | <literal><replaceable>LIMIT</replaceable>=<replaceable>SOFT</replaceable>:<replaceable>HARD</replaceable></literal> | |
1271 | or <literal><replaceable>LIMIT</replaceable>=<replaceable>VALUE</replaceable></literal>, where | |
1272 | <replaceable>LIMIT</replaceable> should refer to a resource limit type, such as | |
1273 | <constant>RLIMIT_NOFILE</constant> or <constant>RLIMIT_NICE</constant>. The <replaceable>SOFT</replaceable> and | |
1274 | <replaceable>HARD</replaceable> fields should refer to the numeric soft and hard resource limit values. If the | |
1b2ad5d9 | 1275 | second form is used, <replaceable>VALUE</replaceable> may specify a value that is used both as soft and hard |
bf428efb LP |
1276 | limit. In place of a numeric value the special string <literal>infinity</literal> may be used to turn off |
1277 | resource limiting for the specific type of resource. This command line option may be used multiple times to | |
1b2ad5d9 | 1278 | control limits on multiple limit types. If used multiple times for the same limit type, the last use |
bf428efb LP |
1279 | wins. For details about resource limits see <citerefentry |
1280 | project='man-pages'><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>. By default | |
1281 | resource limits for the container's init process (PID 1) are set to the same values the Linux kernel originally | |
1282 | passed to the host init system. Note that some resource limits are enforced on resources counted per user, in | |
1283 | particular <constant>RLIMIT_NPROC</constant>. This means that unless user namespacing is deployed | |
1284 | (i.e. <option>--private-users=</option> is used, see above), any limits set will be applied to the resource | |
1285 | usage of the same user on all local containers as well as the host. This means particular care needs to be | |
1286 | taken with these limits as they might be triggered by possibly less trusted code. Example: | |
aefdc112 AK |
1287 | <literal>--rlimit=RLIMIT_NOFILE=8192:16384</literal>.</para> |
1288 | ||
1289 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
bf428efb LP |
1290 | </varlistentry> |
1291 | ||
81f345df LP |
1292 | <varlistentry> |
1293 | <term><option>--oom-score-adjust=</option></term> | |
1294 | ||
1295 | <listitem><para>Changes the OOM ("Out Of Memory") score adjustment value for the container payload. This controls | |
1296 | <filename>/proc/self/oom_score_adj</filename> which influences the preference with which this container is | |
1297 | terminated when memory becomes scarce. For details see <citerefentry | |
1298 | project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Takes an | |
aefdc112 AK |
1299 | integer in the range -1000…1000.</para> |
1300 | ||
1301 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
81f345df LP |
1302 | </varlistentry> |
1303 | ||
d107bb7d LP |
1304 | <varlistentry> |
1305 | <term><option>--cpu-affinity=</option></term> | |
1306 | ||
1307 | <listitem><para>Controls the CPU affinity of the container payload. Takes a comma separated list of CPU numbers | |
1308 | or number ranges (the latter's start and end value separated by dashes). See <citerefentry | |
1309 | project='man-pages'><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry> for | |
aefdc112 AK |
1310 | details.</para> |
1311 | ||
1312 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
d107bb7d LP |
1313 | </varlistentry> |
1314 | ||
c6c8f6e2 | 1315 | <varlistentry> |
d99058c9 | 1316 | <term><option>--personality=</option></term> |
b09c0bba | 1317 | |
d99058c9 LP |
1318 | <listitem><para>Control the architecture ("personality") |
1319 | reported by | |
1320 | <citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
1321 | in the container. Currently, only <literal>x86</literal> and | |
1322 | <literal>x86-64</literal> are supported. This is useful when | |
1323 | running a 32-bit container on a 64-bit host. If this setting | |
1324 | is not used, the personality reported in the container is the | |
aefdc112 AK |
1325 | same as the one reported on the host.</para> |
1326 | ||
1327 | <xi:include href="version-info.xml" xpointer="v209"/></listitem> | |
798d3a52 | 1328 | </varlistentry> |
d99058c9 | 1329 | </variablelist> |
798d3a52 | 1330 | |
d99058c9 LP |
1331 | </refsect2><refsect2> |
1332 | <title>Integration Options</title> | |
798d3a52 | 1333 | |
d99058c9 | 1334 | <variablelist> |
09d423e9 LP |
1335 | <varlistentry> |
1336 | <term><option>--resolv-conf=</option></term> | |
1337 | ||
e309b929 LP |
1338 | <listitem><para>Configures how <filename>/etc/resolv.conf</filename> inside of the container shall be |
1339 | handled (i.e. DNS configuration synchronization from host to container). Takes one of | |
1340 | <literal>off</literal>, <literal>copy-host</literal>, <literal>copy-static</literal>, | |
1341 | <literal>copy-uplink</literal>, <literal>copy-stub</literal>, <literal>replace-host</literal>, | |
1342 | <literal>replace-static</literal>, <literal>replace-uplink</literal>, | |
1343 | <literal>replace-stub</literal>, <literal>bind-host</literal>, <literal>bind-static</literal>, | |
1344 | <literal>bind-uplink</literal>, <literal>bind-stub</literal>, <literal>delete</literal> or | |
1345 | <literal>auto</literal>.</para> | |
1346 | ||
1347 | <para>If set to <literal>off</literal> the <filename>/etc/resolv.conf</filename> file in the | |
1348 | container is left as it is included in the image, and neither modified nor bind mounted over.</para> | |
1349 | ||
1350 | <para>If set to <literal>copy-host</literal>, the <filename>/etc/resolv.conf</filename> file from the | |
1351 | host is copied into the container, unless the file exists already and is not a regular file (e.g. a | |
15102ced ZJS |
1352 | symlink). Similarly, if <literal>replace-host</literal> is used the file is copied, replacing any |
1353 | existing inode, including symlinks. Similarly, if <literal>bind-host</literal> is used, the file is | |
e309b929 LP |
1354 | bind mounted from the host into the container.</para> |
1355 | ||
1356 | <para>If set to <literal>copy-static</literal>, <literal>replace-static</literal> or | |
1357 | <literal>bind-static</literal> the static <filename>resolv.conf</filename> file supplied with | |
1358 | <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1359 | (specifically: <filename>/usr/lib/systemd/resolv.conf</filename>) is copied or bind mounted into the | |
1360 | container.</para> | |
1361 | ||
1362 | <para>If set to <literal>copy-uplink</literal>, <literal>replace-uplink</literal> or | |
1363 | <literal>bind-uplink</literal> the uplink <filename>resolv.conf</filename> file managed by | |
1364 | <filename>systemd-resolved.service</filename> (specifically: | |
1365 | <filename>/run/systemd/resolve/resolv.conf</filename>) is copied or bind mounted into the | |
1366 | container.</para> | |
1367 | ||
1368 | <para>If set to <literal>copy-stub</literal>, <literal>replace-stub</literal> or | |
1369 | <literal>bind-stub</literal> the stub <filename>resolv.conf</filename> file managed by | |
1370 | <filename>systemd-resolved.service</filename> (specifically: | |
1371 | <filename>/run/systemd/resolve/stub-resolv.conf</filename>) is copied or bind mounted into the | |
1372 | container.</para> | |
1373 | ||
1374 | <para>If set to <literal>delete</literal> the <filename>/etc/resolv.conf</filename> file in the | |
1375 | container is deleted if it exists.</para> | |
1376 | ||
1377 | <para>Finally, if set to <literal>auto</literal> the file is left as it is if private networking is | |
1378 | turned on (see <option>--private-network</option>). Otherwise, if | |
e9dd6984 ZJS |
1379 | <filename>systemd-resolved.service</filename> is running its stub <filename>resolv.conf</filename> |
1380 | file is used, and if not the host's <filename>/etc/resolv.conf</filename> file. In the latter cases | |
1381 | the file is copied if the image is writable, and bind mounted otherwise.</para> | |
e309b929 LP |
1382 | |
1383 | <para>It's recommended to use <literal>copy-…</literal> or <literal>replace-…</literal> if the | |
1384 | container shall be able to make changes to the DNS configuration on its own, deviating from the | |
1385 | host's settings. Otherwise <literal>bind</literal> is preferable, as it means direct changes to | |
1386 | <filename>/etc/resolv.conf</filename> in the container are not allowed, as it is a read-only bind | |
1387 | mount (but note that if the container has enough privileges, it might simply go ahead and unmount the | |
1388 | bind mount anyway). Note that both if the file is bind mounted and if it is copied no further | |
1389 | propagation of configuration is generally done after the one-time early initialization (this is | |
1390 | because the file is usually updated through copying and renaming). Defaults to | |
aefdc112 AK |
1391 | <literal>auto</literal>.</para> |
1392 | ||
1393 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
09d423e9 LP |
1394 | </varlistentry> |
1395 | ||
1688841f LP |
1396 | <varlistentry> |
1397 | <term><option>--timezone=</option></term> | |
1398 | ||
e9dd6984 ZJS |
1399 | <listitem><para>Configures how <filename>/etc/localtime</filename> inside of the container |
1400 | (i.e. local timezone synchronization from host to container) shall be handled. Takes one of | |
1401 | <literal>off</literal>, <literal>copy</literal>, <literal>bind</literal>, <literal>symlink</literal>, | |
1402 | <literal>delete</literal> or <literal>auto</literal>. If set to <literal>off</literal> the | |
1403 | <filename>/etc/localtime</filename> file in the container is left as it is included in the image, and | |
1404 | neither modified nor bind mounted over. If set to <literal>copy</literal> the | |
1405 | <filename>/etc/localtime</filename> file of the host is copied into the container. Similarly, if | |
1406 | <literal>bind</literal> is used, the file is bind mounted from the host into the container. If set to | |
1407 | <literal>symlink</literal>, a symlink is created pointing from <filename>/etc/localtime</filename> in | |
1408 | the container to the timezone file in the container that matches the timezone setting on the host. If | |
1409 | set to <literal>delete</literal>, the file in the container is deleted, should it exist. If set to | |
1410 | <literal>auto</literal> and the <filename>/etc/localtime</filename> file of the host is a symlink, | |
1411 | then <literal>symlink</literal> mode is used, and <literal>copy</literal> otherwise, except if the | |
1412 | image is read-only in which case <literal>bind</literal> is used instead. Defaults to | |
aefdc112 AK |
1413 | <literal>auto</literal>.</para> |
1414 | ||
1415 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
1688841f LP |
1416 | </varlistentry> |
1417 | ||
798d3a52 | 1418 | <varlistentry> |
d99058c9 | 1419 | <term><option>--link-journal=</option></term> |
798d3a52 | 1420 | |
d99058c9 LP |
1421 | <listitem><para>Control whether the container's journal shall |
1422 | be made visible to the host system. If enabled, allows viewing | |
1423 | the container's journal files from the host (but not vice | |
1424 | versa). Takes one of <literal>no</literal>, | |
1425 | <literal>host</literal>, <literal>try-host</literal>, | |
1426 | <literal>guest</literal>, <literal>try-guest</literal>, | |
1427 | <literal>auto</literal>. If <literal>no</literal>, the journal | |
1428 | is not linked. If <literal>host</literal>, the journal files | |
1429 | are stored on the host file system (beneath | |
1430 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
1431 | and the subdirectory is bind-mounted into the container at the | |
1432 | same location. If <literal>guest</literal>, the journal files | |
1433 | are stored on the guest file system (beneath | |
1434 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
1435 | and the subdirectory is symlinked into the host at the same | |
1436 | location. <literal>try-host</literal> and | |
1437 | <literal>try-guest</literal> do the same but do not fail if | |
1438 | the host does not have persistent journaling enabled. If | |
1439 | <literal>auto</literal> (the default), and the right | |
1440 | subdirectory of <filename>/var/log/journal</filename> exists, | |
1441 | it will be bind mounted into the container. If the | |
1442 | subdirectory does not exist, no linking is performed. | |
1443 | Effectively, booting a container once with | |
1444 | <literal>guest</literal> or <literal>host</literal> will link | |
1445 | the journal persistently if further on the default of | |
1446 | <literal>auto</literal> is used.</para> | |
1447 | ||
1448 | <para>Note that <option>--link-journal=try-guest</option> is the default if the | |
aefdc112 AK |
1449 | <filename>systemd-nspawn@.service</filename> template unit file is used.</para> |
1450 | ||
1451 | <xi:include href="version-info.xml" xpointer="v187"/></listitem> | |
798d3a52 ZJS |
1452 | </varlistentry> |
1453 | ||
d99058c9 LP |
1454 | <varlistentry> |
1455 | <term><option>-j</option></term> | |
1456 | ||
1457 | <listitem><para>Equivalent to | |
aefdc112 AK |
1458 | <option>--link-journal=try-guest</option>.</para> |
1459 | ||
1460 | <xi:include href="version-info.xml" xpointer="v187"/></listitem> | |
d99058c9 LP |
1461 | </varlistentry> |
1462 | ||
1463 | </variablelist> | |
1464 | ||
1465 | </refsect2><refsect2> | |
1466 | <title>Mount Options</title> | |
1467 | ||
1468 | <variablelist> | |
1469 | ||
798d3a52 ZJS |
1470 | <varlistentry> |
1471 | <term><option>--bind=</option></term> | |
1472 | <term><option>--bind-ro=</option></term> | |
1473 | ||
86c0dd4a | 1474 | <listitem><para>Bind mount a file or directory from the host into the container. Takes one of: a path |
c7a4890c LP |
1475 | argument — in which case the specified path will be mounted from the host to the same path in the container, or |
1476 | a colon-separated pair of paths — in which case the first specified path is the source in the host, and the | |
1477 | second path is the destination in the container, or a colon-separated triple of source path, destination path | |
86c0dd4a | 1478 | and mount options. The source path may optionally be prefixed with a <literal>+</literal> character. If so, the |
c7a4890c LP |
1479 | source path is taken relative to the image's root directory. This permits setting up bind mounts within the |
1480 | container image. The source path may be specified as empty string, in which case a temporary directory below | |
3b121157 | 1481 | the host's <filename>/var/tmp/</filename> directory is used. It is automatically removed when the container is |
448f7377 DDM |
1482 | shut down. If the source path is not absolute, it is resolved relative to the current working directory. |
1483 | The <option>--bind-ro=</option> option creates read-only bind mounts. Backslash escapes are interpreted, | |
c0c8f718 AV |
1484 | so <literal>\:</literal> may be used to embed colons in either path. This option may be specified |
1485 | multiple times for creating multiple independent bind mount points.</para> | |
1486 | ||
1487 | <para>Mount options are comma-separated. <option>rbind</option> and <option>norbind</option> control whether | |
477eac0a | 1488 | to create a recursive or a regular bind mount. Defaults to <option>rbind</option>. <option>noidmap</option>, |
2b2777ed QD |
1489 | <option>idmap</option>, and <option>rootidmap</option> control ID mapping.</para> |
1490 | ||
1491 | <para>Using <option>idmap</option> or <option>rootidmap</option> requires support by the source filesystem | |
477eac0a | 1492 | for user/group ID mapped mounts. Defaults to <option>noidmap</option>. With <option>x</option> being the container's UID range |
2b2777ed QD |
1493 | offset, <option>y</option> being the length of the container's UID range, and <option>p</option> being the |
1494 | owner UID of the bind mount source inode on the host: | |
1495 | ||
1496 | <itemizedlist> | |
1497 | <listitem><para>If <option>noidmap</option> is used, any user <option>z</option> in the range | |
1498 | <option>0 … y</option> seen from inside of the container is mapped to <option>x + z</option> in the | |
8b9f0921 | 1499 | <option>x … x + y</option> range on the host. Other host users are mapped to |
2b2777ed | 1500 | <option>nobody</option> inside the container.</para></listitem> |
8fb35004 | 1501 | |
2b2777ed QD |
1502 | <listitem><para>If <option>idmap</option> is used, any user <option>z</option> in the UID range |
1503 | <option>0 … y</option> as seen from inside the container is mapped to the same <option>z</option> | |
8fb35004 ZJS |
1504 | in the same <option>0 … y</option> range on the host. Other host users are mapped to |
1505 | <option>nobody</option> inside the container.</para></listitem> | |
1506 | ||
2b2777ed | 1507 | <listitem><para>If <option>rootidmap</option> is used, the user <option>0</option> seen from inside |
8fb35004 ZJS |
1508 | of the container is mapped to <option>p</option> on the host. Other host users are mapped to |
1509 | <option>nobody</option> inside the container.</para></listitem> | |
2b2777ed QD |
1510 | </itemizedlist></para> |
1511 | ||
1512 | <para>Whichever ID mapping option is used, the same mapping will be used for users and groups IDs. If | |
a9ba6f8a | 1513 | <option>rootidmap</option> is used, the group owning the bind mounted directory will have no effect.</para> |
994a6364 LP |
1514 | |
1515 | <para>Note that when this option is used in combination with <option>--private-users</option>, the resulting | |
1516 | mount points will be owned by the <constant>nobody</constant> user. That's because the mount and its files and | |
1517 | directories continue to be owned by the relevant host users and groups, which do not exist in the container, | |
1518 | and thus show up under the wildcard UID 65534 (nobody). If such bind mounts are created, it is recommended to | |
c0c8f718 | 1519 | make them read-only, using <option>--bind-ro=</option>. Alternatively you can use the "idmap" mount option to |
aefdc112 AK |
1520 | map the filesystem IDs.</para> |
1521 | ||
1522 | <xi:include href="version-info.xml" xpointer="v198"/></listitem> | |
798d3a52 ZJS |
1523 | </varlistentry> |
1524 | ||
a06c9ac2 LP |
1525 | <varlistentry> |
1526 | <term><option>--bind-user=</option></term> | |
1527 | ||
1528 | <listitem><para>Binds the home directory of the specified user on the host into the container. Takes | |
1529 | the name of an existing user on the host as argument. May be used multiple times to bind multiple | |
1530 | users into the container. This does three things:</para> | |
1531 | ||
1532 | <orderedlist> | |
1533 | <listitem><para>The user's home directory is bind mounted from the host into | |
f39d7d00 | 1534 | <filename>/run/host/home/</filename>.</para></listitem> |
a06c9ac2 LP |
1535 | |
1536 | <listitem><para>An additional UID/GID mapping is added that maps the host user's UID/GID to a | |
1537 | container UID/GID, allocated from the 60514…60577 range.</para></listitem> | |
1538 | ||
1539 | <listitem><para>A JSON user and group record is generated in <filename>/run/userdb/</filename> that | |
1540 | describes the mapped user. It contains a minimized representation of the host's user record, | |
1541 | adjusted to the UID/GID and home directory path assigned to the user in the container. The | |
1542 | <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1543 | glibc NSS module will pick up these records from there and make them available in the container's | |
1544 | user/group databases.</para></listitem> | |
1545 | </orderedlist> | |
1546 | ||
1547 | <para>The combination of the three operations above ensures that it is possible to log into the | |
be0d27ee ZJS |
1548 | container using the same account information as on the host. The user is only mapped transiently, |
1549 | while the container is running, and the mapping itself does not result in persistent changes to the | |
1550 | container (except maybe for log messages generated at login time, and similar). Note that in | |
1551 | particular the UID/GID assignment in the container is not made persistently. If the user is mapped | |
1552 | transiently, it is best to not allow the user to make persistent changes to the container. If the | |
1553 | user leaves files or directories owned by the user, and those UIDs/GIDs are reused during later | |
a06c9ac2 LP |
1554 | container invocations (possibly with a different <option>--bind-user=</option> mapping), those files |
1555 | and directories will be accessible to the "new" user.</para> | |
1556 | ||
1557 | <para>The user/group record mapping only works if the container contains systemd 249 or newer, with | |
1558 | <command>nss-systemd</command> properly configured in <filename>nsswitch.conf</filename>. See | |
1559 | <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry> for | |
1560 | details.</para> | |
1561 | ||
1562 | <para>Note that the user record propagated from the host into the container will contain the UNIX | |
1563 | password hash of the user, so that seamless logins in the container are possible. If the container is | |
1564 | less trusted than the host it's hence important to use a strong UNIX password hash function | |
1565 | (e.g. yescrypt or similar, with the <literal>$y$</literal> hash prefix).</para> | |
1566 | ||
1567 | <para>When binding a user from the host into the container checks are executed to ensure that the | |
1568 | username is not yet known in the container. Moreover, it is checked that the UID/GID allocated for it | |
1569 | is not currently defined in the user/group databases of the container. Both checks directly access | |
1570 | the container's <filename>/etc/passwd</filename> and <filename>/etc/group</filename>, and thus might | |
1571 | not detect existing accounts in other databases.</para> | |
1572 | ||
1573 | <para>This operation is only supported in combination with | |
ec07c3c8 AK |
1574 | <option>--private-users=</option>/<option>-U</option>.</para> |
1575 | ||
1576 | <xi:include href="version-info.xml" xpointer="v249"/></listitem> | |
a06c9ac2 LP |
1577 | </varlistentry> |
1578 | ||
3d6c3675 LP |
1579 | <varlistentry> |
1580 | <term><option>--inaccessible=</option></term> | |
1581 | ||
1582 | <listitem><para>Make the specified path inaccessible in the container. This over-mounts the specified path | |
1583 | (which must exist in the container) with a file node of the same type that is empty and has the most | |
1584 | restrictive access mode supported. This is an effective way to mask files, directories and other file system | |
1585 | objects from the container payload. This option may be used more than once in case all specified paths are | |
ec07c3c8 AK |
1586 | masked.</para> |
1587 | ||
1588 | <xi:include href="version-info.xml" xpointer="v242"/></listitem> | |
3d6c3675 LP |
1589 | </varlistentry> |
1590 | ||
798d3a52 ZJS |
1591 | <varlistentry> |
1592 | <term><option>--tmpfs=</option></term> | |
1593 | ||
b23f1628 LP |
1594 | <listitem><para>Mount a tmpfs file system into the container. Takes a single absolute path argument that |
1595 | specifies where to mount the tmpfs instance to (in which case the directory access mode will be chosen as 0755, | |
1596 | owned by root/root), or optionally a colon-separated pair of path and mount option string that is used for | |
1597 | mounting (in which case the kernel default for access mode and owner will be chosen, unless otherwise | |
1598 | specified). Backslash escapes are interpreted in the path, so <literal>\:</literal> may be used to embed colons | |
1599 | in the path.</para> | |
1600 | ||
1601 | <para>Note that this option cannot be used to replace the root file system of the container with a temporary | |
1602 | file system. However, the <option>--volatile=</option> option described below provides similar | |
aefdc112 AK |
1603 | functionality, with a focus on implementing stateless operating system images.</para> |
1604 | ||
1605 | <xi:include href="version-info.xml" xpointer="v214"/></listitem> | |
798d3a52 ZJS |
1606 | </varlistentry> |
1607 | ||
5a8af538 LP |
1608 | <varlistentry> |
1609 | <term><option>--overlay=</option></term> | |
1610 | <term><option>--overlay-ro=</option></term> | |
1611 | ||
f075e32c DDM |
1612 | <listitem><para>Combine multiple directory trees into one overlay file system and mount it into the |
1613 | container. Takes a list of colon-separated paths to the directory trees to combine and the | |
1614 | destination mount point.</para> | |
1615 | ||
1616 | <para>Backslash escapes are interpreted in the paths, so <literal>\:</literal> may be used to embed | |
1617 | colons in the paths.</para> | |
1618 | ||
1619 | <para>If three or more paths are specified, then the last specified path is the destination mount | |
1620 | point in the container, all paths specified before refer to directory trees on the host and are | |
1621 | combined in the specified order into one overlay file system. The left-most path is hence the lowest | |
1622 | directory tree, the second-to-last path the highest directory tree in the stacking order. If | |
1623 | <option>--overlay-ro=</option> is used instead of <option>--overlay=</option>, a read-only overlay | |
1624 | file system is created. If a writable overlay file system is created, all changes made to it are | |
1625 | written to the highest directory tree in the stacking order, i.e. the second-to-last specified. | |
2eadf91c RM |
1626 | </para> |
1627 | ||
f075e32c DDM |
1628 | <para>If only two paths are specified, then the second specified path is used both as the top-level |
1629 | directory tree in the stacking order as seen from the host, as well as the mount point for the | |
1630 | overlay file system in the container. At least two paths have to be specified.</para> | |
5a8af538 | 1631 | |
3b121157 ZJS |
1632 | <para>The source paths may optionally be prefixed with <literal>+</literal> character. If so they are |
1633 | taken relative to the image's root directory. The uppermost source path may also be specified as an | |
1634 | empty string, in which case a temporary directory below the host's <filename>/var/tmp/</filename> is | |
1635 | used. The directory is removed automatically when the container is shut down. This behaviour is | |
1636 | useful in order to make read-only container directories writable while the container is running. For | |
1637 | example, use <literal>--overlay=+/var::/var</literal> in order to automatically overlay a writable | |
448f7377 DDM |
1638 | temporary directory on a read-only <filename>/var/</filename> directory. If a source path is not |
1639 | absolute, it is resolved relative to the current working directory.</para> | |
86c0dd4a | 1640 | |
5a8af538 | 1641 | <para>For details about overlay file systems, see <ulink |
0e685823 | 1642 | url="https://docs.kernel.org/filesystems/overlayfs.html">Overlay Filesystem</ulink>. |
2f8211c6 ZJS |
1643 | Note that the semantics of overlay file systems are substantially different from normal file systems, |
1644 | in particular regarding reported device and inode information. Device and inode information may | |
1645 | change for a file while it is being written to, and processes might see out-of-date versions of files | |
1646 | at times. Note that this switch automatically derives the <literal>workdir=</literal> mount option | |
1647 | for the overlay file system from the top-level directory tree, making it a sibling of it. It is hence | |
1648 | essential that the top-level directory tree is not a mount point itself (since the working directory | |
1649 | must be on the same file system as the top-most directory tree). Also note that the | |
1650 | <literal>lowerdir=</literal> mount option receives the paths to stack in the opposite order of this | |
1651 | switch.</para> | |
b23f1628 LP |
1652 | |
1653 | <para>Note that this option cannot be used to replace the root file system of the container with an overlay | |
d99058c9 | 1654 | file system. However, the <option>--volatile=</option> option described above provides similar functionality, |
aefdc112 AK |
1655 | with a focus on implementing stateless operating system images.</para> |
1656 | ||
1657 | <xi:include href="version-info.xml" xpointer="v220"/></listitem> | |
5a8af538 | 1658 | </varlistentry> |
d99058c9 | 1659 | </variablelist> |
730bdfed | 1660 | </refsect2> |
5a8af538 | 1661 | |
730bdfed | 1662 | <refsect2> |
d99058c9 | 1663 | <title>Input/Output Options</title> |
798d3a52 | 1664 | |
d99058c9 | 1665 | <variablelist> |
3d6c3675 LP |
1666 | <varlistentry> |
1667 | <term><option>--console=</option><replaceable>MODE</replaceable></term> | |
1668 | ||
7a25ba55 ZJS |
1669 | <listitem><para>Configures how to set up standard input, output and error output for the container |
1670 | payload, as well as the <filename>/dev/console</filename> device for the container. Takes one of | |
10e8a60b LP |
1671 | <option>interactive</option>, <option>read-only</option>, <option>passive</option>, |
1672 | <option>pipe</option> or <option>autopipe</option>. If <option>interactive</option>, a pseudo-TTY is | |
1673 | allocated and made available as <filename>/dev/console</filename> in the container. It is then | |
1674 | bi-directionally connected to the standard input and output passed to | |
1675 | <command>systemd-nspawn</command>. <option>read-only</option> is similar but only the output of the | |
1676 | container is propagated and no input from the caller is read. If <option>passive</option>, a pseudo | |
1677 | TTY is allocated, but it is not connected anywhere. In <option>pipe</option> mode no pseudo TTY is | |
1678 | allocated, but the standard input, output and error output file descriptors passed to | |
1679 | <command>systemd-nspawn</command> are passed on — as they are — to the container payload, see the | |
1680 | following paragraph. Finally, <option>autopipe</option> mode operates like | |
1681 | <option>interactive</option> when <command>systemd-nspawn</command> is invoked on a terminal, and | |
1682 | like <option>pipe</option> otherwise. Defaults to <option>interactive</option> if | |
3d6c3675 | 1683 | <command>systemd-nspawn</command> is invoked from a terminal, and <option>read-only</option> |
7a25ba55 ZJS |
1684 | otherwise.</para> |
1685 | ||
1686 | <para>In <option>pipe</option> mode, <filename>/dev/console</filename> will not exist in the | |
1687 | container. This means that the container payload generally cannot be a full init system as init | |
1688 | systems tend to require <filename>/dev/console</filename> to be available. On the other hand, in this | |
1689 | mode container invocations can be used within shell pipelines. This is because intermediary pseudo | |
1690 | TTYs do not permit independent bidirectional propagation of the end-of-file (EOF) condition, which is | |
1691 | necessary for shell pipelines to work correctly. <emphasis>Note that the <option>pipe</option> mode | |
1692 | should be used carefully</emphasis>, as passing arbitrary file descriptors to less trusted container | |
1693 | payloads might open up unwanted interfaces for access by the container payload. For example, if a | |
1694 | passed file descriptor refers to a TTY of some form, APIs such as <constant>TIOCSTI</constant> may be | |
1695 | used to synthesize input that might be used for escaping the container. Hence <option>pipe</option> | |
1696 | mode should only be used if the payload is sufficiently trusted or when the standard | |
ec07c3c8 AK |
1697 | input/output/error output file descriptors are known safe, for example pipes.</para> |
1698 | ||
1699 | <xi:include href="version-info.xml" xpointer="v242"/></listitem> | |
3d6c3675 LP |
1700 | </varlistentry> |
1701 | ||
1702 | <varlistentry> | |
1703 | <term><option>--pipe</option></term> | |
1704 | <term><option>-P</option></term> | |
1705 | ||
ec07c3c8 AK |
1706 | <listitem><para>Equivalent to <option>--console=pipe</option>.</para> |
1707 | ||
1708 | <xi:include href="version-info.xml" xpointer="v242"/></listitem> | |
3d6c3675 | 1709 | </varlistentry> |
60cc90b9 LP |
1710 | </variablelist> |
1711 | ||
730bdfed ZJS |
1712 | </refsect2> |
1713 | <refsect2> | |
1714 | <title>Credentials</title> | |
1715 | ||
1716 | <variablelist> | |
1717 | <varlistentry> | |
1718 | <term><option>--load-credential=</option><replaceable>ID</replaceable>:<replaceable>PATH</replaceable></term> | |
1719 | <term><option>--set-credential=</option><replaceable>ID</replaceable>:<replaceable>VALUE</replaceable></term> | |
1720 | ||
1721 | <listitem><para>Pass a credential to the container. These two options correspond to the | |
1722 | <varname>LoadCredential=</varname> and <varname>SetCredential=</varname> settings in unit files. See | |
1723 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for | |
1724 | details about these concepts, as well as the syntax of the option's arguments.</para> | |
1725 | ||
1726 | <para>Note: when <command>systemd-nspawn</command> runs as systemd system service it can propagate | |
1727 | the credentials it received via <varname>LoadCredential=</varname>/<varname>SetCredential=</varname> | |
1728 | to the container payload. A systemd service manager running as PID 1 in the container can further | |
1729 | propagate them to the services it itself starts. It is thus possible to easily propagate credentials | |
1730 | from a parent service manager to a container manager service and from there into its payload. This | |
1731 | can even be done recursively.</para> | |
1732 | ||
1733 | <para>In order to embed binary data into the credential data for <option>--set-credential=</option>, | |
1734 | use C-style escaping (i.e. <literal>\n</literal> to embed a newline, or <literal>\x00</literal> to | |
1735 | embed a <constant>NUL</constant> byte). Note that the invoking shell might already apply unescaping | |
1736 | once, hence this might require double escaping!.</para> | |
1737 | ||
1738 | <para>The | |
1739 | <citerefentry><refentrytitle>systemd-sysusers.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1740 | and | |
1741 | <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1742 | services read credentials configured this way for the purpose of configuring the container's root | |
1743 | user's password and shell, as well as system locale, keymap and timezone during the first boot | |
1744 | process of the container. This is particularly useful in combination with | |
1745 | <option>--volatile=yes</option> where every single boot appears as first boot, since configuration | |
1746 | applied to <filename>/etc/</filename> is lost on container reboot cycles. See the respective man | |
1747 | pages for details. Example:</para> | |
1748 | ||
1749 | <programlisting># systemd-nspawn -i image.raw \ | |
1750 | --volatile=yes \ | |
1751 | --set-credential=firstboot.locale:de_DE.UTF-8 \ | |
1752 | --set-credential=passwd.hashed-password.root:'$y$j9T$yAuRJu1o5HioZAGDYPU5d.$F64ni6J2y2nNQve90M/p0ZP0ECP/qqzipNyaY9fjGpC' \ | |
1753 | -b</programlisting> | |
1754 | ||
1755 | <para>The above command line will invoke the specified image file <filename>image.raw</filename> in | |
1756 | volatile mode, i.e. with empty <filename>/etc/</filename> and <filename>/var/</filename>. The | |
1757 | container payload will recognize this as a first boot, and will invoke | |
1758 | <filename>systemd-firstboot.service</filename>, which then reads the two passed credentials to | |
1759 | configure the system's initial locale and root password.</para> | |
ec07c3c8 AK |
1760 | |
1761 | <xi:include href="version-info.xml" xpointer="v247"/> | |
730bdfed | 1762 | </listitem> |
60cc90b9 | 1763 | </varlistentry> |
730bdfed | 1764 | </variablelist> |
60cc90b9 LP |
1765 | |
1766 | </refsect2><refsect2> | |
1767 | <title>Other</title> | |
1768 | ||
1769 | <variablelist> | |
bb068de0 | 1770 | <xi:include href="standard-options.xml" xpointer="no-pager" /> |
798d3a52 ZJS |
1771 | <xi:include href="standard-options.xml" xpointer="help" /> |
1772 | <xi:include href="standard-options.xml" xpointer="version" /> | |
1773 | </variablelist> | |
d99058c9 | 1774 | </refsect2> |
798d3a52 ZJS |
1775 | </refsect1> |
1776 | ||
4ef3ca34 | 1777 | <xi:include href="common-variables.xml" /> |
bb068de0 | 1778 | |
798d3a52 ZJS |
1779 | <refsect1> |
1780 | <title>Examples</title> | |
1781 | ||
1782 | <example> | |
12c4ee0a ZJS |
1783 | <title>Download a |
1784 | <ulink url="https://getfedora.org">Fedora</ulink> image and start a shell in it</title> | |
798d3a52 | 1785 | |
3797fd0a | 1786 | <programlisting># machinectl pull-raw --verify=no \ |
b12a67ae AZ |
1787 | https://download.fedoraproject.org/pub/fedora/linux/releases/&fedora_latest_version;/Cloud/x86_64/images/Fedora-Cloud-Base-&fedora_latest_version;-&fedora_cloud_release;.x86_64.raw.xz \ |
1788 | Fedora-Cloud-Base-&fedora_latest_version;-&fedora_cloud_release;.x86-64 | |
1789 | # systemd-nspawn -M Fedora-Cloud-Base-&fedora_latest_version;-&fedora_cloud_release;.x86-64</programlisting> | |
e0ea94c1 | 1790 | |
798d3a52 ZJS |
1791 | <para>This downloads an image using |
1792 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1793 | and opens a shell in it.</para> | |
1794 | </example> | |
e0ea94c1 | 1795 | |
798d3a52 ZJS |
1796 | <example> |
1797 | <title>Build and boot a minimal Fedora distribution in a container</title> | |
8f7a3c14 | 1798 | |
7a8aa0ec | 1799 | <programlisting># dnf -y --releasever=&fedora_latest_version; --installroot=/var/lib/machines/f&fedora_latest_version; \ |
8c4db562 | 1800 | --repo=fedora --repo=updates --setopt=install_weak_deps=False install \ |
5015b501 | 1801 | passwd dnf fedora-release vim-minimal util-linux systemd systemd-networkd |
7a8aa0ec | 1802 | # systemd-nspawn -bD /var/lib/machines/f&fedora_latest_version;</programlisting> |
8f7a3c14 | 1803 | |
798d3a52 | 1804 | <para>This installs a minimal Fedora distribution into the |
b0343f8c | 1805 | directory <filename index="false">/var/lib/machines/f&fedora_latest_version;</filename> |
e9dd6984 | 1806 | and then boots that OS in a namespace container. Because the installation |
55107232 ZJS |
1807 | is located underneath the standard <filename>/var/lib/machines/</filename> |
1808 | directory, it is also possible to start the machine using | |
7a8aa0ec | 1809 | <command>systemd-nspawn -M f&fedora_latest_version;</command>.</para> |
798d3a52 | 1810 | </example> |
8f7a3c14 | 1811 | |
798d3a52 ZJS |
1812 | <example> |
1813 | <title>Spawn a shell in a container of a minimal Debian unstable distribution</title> | |
8f7a3c14 | 1814 | |
7f8b3d1d | 1815 | <programlisting># debootstrap unstable ~/debian-tree/ |
25f5971b | 1816 | # systemd-nspawn -D ~/debian-tree/</programlisting> |
8f7a3c14 | 1817 | |
798d3a52 ZJS |
1818 | <para>This installs a minimal Debian unstable distribution into |
1819 | the directory <filename>~/debian-tree/</filename> and then | |
e9dd6984 | 1820 | spawns a shell from this image in a namespace container.</para> |
12c4ee0a ZJS |
1821 | |
1822 | <para><command>debootstrap</command> supports | |
1823 | <ulink url="https://www.debian.org">Debian</ulink>, | |
1824 | <ulink url="https://www.ubuntu.com">Ubuntu</ulink>, | |
1825 | and <ulink url="https://www.tanglu.org">Tanglu</ulink> | |
1826 | out of the box, so the same command can be used to install any of those. For other | |
1827 | distributions from the Debian family, a mirror has to be specified, see | |
1828 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
1829 | </para> | |
798d3a52 | 1830 | </example> |
8f7a3c14 | 1831 | |
798d3a52 | 1832 | <example> |
12c4ee0a ZJS |
1833 | <title>Boot a minimal |
1834 | <ulink url="https://www.archlinux.org">Arch Linux</ulink> distribution in a container</title> | |
68562936 | 1835 | |
9a027075 | 1836 | <programlisting># pacstrap -c ~/arch-tree/ base |
68562936 WG |
1837 | # systemd-nspawn -bD ~/arch-tree/</programlisting> |
1838 | ||
ff9b60f3 | 1839 | <para>This installs a minimal Arch Linux distribution into the |
798d3a52 ZJS |
1840 | directory <filename>~/arch-tree/</filename> and then boots an OS |
1841 | in a namespace container in it.</para> | |
1842 | </example> | |
68562936 | 1843 | |
f518ee04 | 1844 | <example> |
12c4ee0a ZJS |
1845 | <title>Install the |
1846 | <ulink url="https://software.opensuse.org/distributions/tumbleweed">OpenSUSE Tumbleweed</ulink> | |
1847 | rolling distribution</title> | |
f518ee04 ZJS |
1848 | |
1849 | <programlisting># zypper --root=/var/lib/machines/tumbleweed ar -c \ | |
1850 | https://download.opensuse.org/tumbleweed/repo/oss tumbleweed | |
1851 | # zypper --root=/var/lib/machines/tumbleweed refresh | |
1852 | # zypper --root=/var/lib/machines/tumbleweed install --no-recommends \ | |
1853 | systemd shadow zypper openSUSE-release vim | |
1854 | # systemd-nspawn -M tumbleweed passwd root | |
1855 | # systemd-nspawn -M tumbleweed -b</programlisting> | |
1856 | </example> | |
1857 | ||
798d3a52 | 1858 | <example> |
17cbb288 | 1859 | <title>Boot into an ephemeral snapshot of the host system</title> |
f9f4dd51 | 1860 | |
798d3a52 | 1861 | <programlisting># systemd-nspawn -D / -xb</programlisting> |
f9f4dd51 | 1862 | |
17cbb288 LP |
1863 | <para>This runs a copy of the host system in a snapshot which is removed immediately when the container |
1864 | exits. All file system changes made during runtime will be lost on shutdown, hence.</para> | |
798d3a52 | 1865 | </example> |
f9f4dd51 | 1866 | |
798d3a52 ZJS |
1867 | <example> |
1868 | <title>Run a container with SELinux sandbox security contexts</title> | |
a8828ed9 | 1869 | |
798d3a52 | 1870 | <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container |
3797fd0a ZJS |
1871 | # systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 \ |
1872 | -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh</programlisting> | |
798d3a52 | 1873 | </example> |
b53ede69 PW |
1874 | |
1875 | <example> | |
1876 | <title>Run a container with an OSTree deployment</title> | |
1877 | ||
3797fd0a ZJS |
1878 | <programlisting># systemd-nspawn -b -i ~/image.raw \ |
1879 | --pivot-root=/ostree/deploy/$OS/deploy/$CHECKSUM:/sysroot \ | |
1880 | --bind=+/sysroot/ostree/deploy/$OS/var:/var</programlisting> | |
b53ede69 | 1881 | </example> |
798d3a52 ZJS |
1882 | </refsect1> |
1883 | ||
1884 | <refsect1> | |
1885 | <title>Exit status</title> | |
1886 | ||
1887 | <para>The exit code of the program executed in the container is | |
1888 | returned.</para> | |
1889 | </refsect1> | |
1890 | ||
1891 | <refsect1> | |
1892 | <title>See Also</title> | |
1893 | <para> | |
1894 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
f757855e | 1895 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
798d3a52 ZJS |
1896 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
1897 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
798d3a52 ZJS |
1898 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
1899 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
f518ee04 | 1900 | <citerefentry project='mankier'><refentrytitle>zypper</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
798d3a52 ZJS |
1901 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
1902 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
be57c176 | 1903 | <citerefentry project='url'><refentrytitle url='https://btrfs.readthedocs.io/en/latest/btrfs.html'>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
798d3a52 ZJS |
1904 | </para> |
1905 | </refsect1> | |
8f7a3c14 LP |
1906 | |
1907 | </refentry> |