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f757855e | 1 | <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
8f7a3c14 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2010 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
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11 | under the terms of the GNU Lesser General Public License as published by |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
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13 | (at your option) any later version. |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 18 | Lesser General Public License for more details. |
8f7a3c14 | 19 | |
5430f7f2 | 20 | You should have received a copy of the GNU Lesser General Public License |
8f7a3c14 LP |
21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
22 | --> | |
23 | ||
dfdebb1b | 24 | <refentry id="systemd-nspawn" |
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25 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
26 | ||
27 | <refentryinfo> | |
28 | <title>systemd-nspawn</title> | |
29 | <productname>systemd</productname> | |
30 | ||
31 | <authorgroup> | |
32 | <author> | |
33 | <contrib>Developer</contrib> | |
34 | <firstname>Lennart</firstname> | |
35 | <surname>Poettering</surname> | |
36 | <email>lennart@poettering.net</email> | |
37 | </author> | |
38 | </authorgroup> | |
39 | </refentryinfo> | |
40 | ||
41 | <refmeta> | |
42 | <refentrytitle>systemd-nspawn</refentrytitle> | |
43 | <manvolnum>1</manvolnum> | |
44 | </refmeta> | |
45 | ||
46 | <refnamediv> | |
47 | <refname>systemd-nspawn</refname> | |
48 | <refpurpose>Spawn a namespace container for debugging, testing and building</refpurpose> | |
49 | </refnamediv> | |
50 | ||
51 | <refsynopsisdiv> | |
52 | <cmdsynopsis> | |
53 | <command>systemd-nspawn</command> | |
54 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
55 | <arg choice="opt"><replaceable>COMMAND</replaceable> | |
56 | <arg choice="opt" rep="repeat">ARGS</arg> | |
57 | </arg> | |
58 | </cmdsynopsis> | |
59 | <cmdsynopsis> | |
60 | <command>systemd-nspawn</command> | |
4447e799 | 61 | <arg choice="plain">--boot</arg> |
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62 | <arg choice="opt" rep="repeat">OPTIONS</arg> |
63 | <arg choice="opt" rep="repeat">ARGS</arg> | |
64 | </cmdsynopsis> | |
65 | </refsynopsisdiv> | |
66 | ||
67 | <refsect1> | |
68 | <title>Description</title> | |
69 | ||
70 | <para><command>systemd-nspawn</command> may be used to run a | |
71 | command or OS in a light-weight namespace container. In many ways | |
72 | it is similar to | |
73 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
74 | but more powerful since it fully virtualizes the file system | |
75 | hierarchy, as well as the process tree, the various IPC subsystems | |
76 | and the host and domain name.</para> | |
77 | ||
78 | <para><command>systemd-nspawn</command> limits access to various | |
79 | kernel interfaces in the container to read-only, such as | |
80 | <filename>/sys</filename>, <filename>/proc/sys</filename> or | |
81 | <filename>/sys/fs/selinux</filename>. Network interfaces and the | |
82 | system clock may not be changed from within the container. Device | |
83 | nodes may not be created. The host system cannot be rebooted and | |
84 | kernel modules may not be loaded from within the container.</para> | |
85 | ||
86 | <para>Note that even though these security precautions are taken | |
7de7ee62 | 87 | <command>systemd-nspawn</command> is not suitable for fully secure |
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88 | container setups. Many of the security features may be |
89 | circumvented and are hence primarily useful to avoid accidental | |
7de7ee62 | 90 | changes to the host system from the container.</para> |
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91 | |
92 | <para>In contrast to | |
93 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command> | |
94 | may be used to boot full Linux-based operating systems in a | |
95 | container.</para> | |
96 | ||
97 | <para>Use a tool like | |
98 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
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99 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
100 | or | |
101 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
102 | to set up an OS directory tree suitable as file system hierarchy | |
103 | for <command>systemd-nspawn</command> containers.</para> | |
104 | ||
105 | <para>Note that <command>systemd-nspawn</command> will mount file | |
106 | systems private to the container to <filename>/dev</filename>, | |
107 | <filename>/run</filename> and similar. These will not be visible | |
108 | outside of the container, and their contents will be lost when the | |
109 | container exits.</para> | |
110 | ||
111 | <para>Note that running two <command>systemd-nspawn</command> | |
112 | containers from the same directory tree will not make processes in | |
113 | them see each other. The PID namespace separation of the two | |
114 | containers is complete and the containers will share very few | |
115 | runtime objects except for the underlying file system. Use | |
116 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s | |
117 | <command>login</command> command to request an additional login | |
118 | prompt in a running container.</para> | |
119 | ||
120 | <para><command>systemd-nspawn</command> implements the | |
121 | <ulink | |
122 | url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container | |
123 | Interface</ulink> specification.</para> | |
124 | ||
125 | <para>As a safety check <command>systemd-nspawn</command> will | |
126 | verify the existence of <filename>/usr/lib/os-release</filename> | |
127 | or <filename>/etc/os-release</filename> in the container tree | |
128 | before starting the container (see | |
129 | <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). | |
130 | It might be necessary to add this file to the container tree | |
131 | manually if the OS of the container is too old to contain this | |
132 | file out-of-the-box.</para> | |
133 | </refsect1> | |
134 | ||
135 | <refsect1> | |
136 | <title>Options</title> | |
137 | ||
138 | <para>If option <option>-b</option> is specified, the arguments | |
139 | are used as arguments for the init binary. Otherwise, | |
140 | <replaceable>COMMAND</replaceable> specifies the program to launch | |
141 | in the container, and the remaining arguments are used as | |
142 | arguments for this program. If <option>-b</option> is not used and | |
ff9b60f3 | 143 | no arguments are specified, a shell is launched in the |
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144 | container.</para> |
145 | ||
146 | <para>The following options are understood:</para> | |
147 | ||
148 | <variablelist> | |
149 | <varlistentry> | |
150 | <term><option>-D</option></term> | |
151 | <term><option>--directory=</option></term> | |
152 | ||
153 | <listitem><para>Directory to use as file system root for the | |
154 | container.</para> | |
155 | ||
156 | <para>If neither <option>--directory=</option>, nor | |
157 | <option>--image=</option> is specified the directory is | |
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158 | determined by searching for a directory named the same as the |
159 | machine name specified with <option>--machine=</option>. See | |
160 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
161 | section "Files and Directories" for the precise search path.</para> | |
162 | ||
163 | <para>If neither <option>--directory=</option>, | |
164 | <option>--image=</option>, nor <option>--machine=</option> | |
165 | are specified, the current directory will | |
166 | be used. May not be specified together with | |
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167 | <option>--image=</option>.</para></listitem> |
168 | </varlistentry> | |
169 | ||
170 | <varlistentry> | |
171 | <term><option>--template=</option></term> | |
172 | ||
173 | <listitem><para>Directory or <literal>btrfs</literal> | |
174 | subvolume to use as template for the container's root | |
175 | directory. If this is specified and the container's root | |
176 | directory (as configured by <option>--directory=</option>) | |
177 | does not yet exist it is created as <literal>btrfs</literal> | |
178 | subvolume and populated from this template tree. Ideally, the | |
179 | specified template path refers to the root of a | |
180 | <literal>btrfs</literal> subvolume, in which case a simple | |
181 | copy-on-write snapshot is taken, and populating the root | |
182 | directory is instant. If the specified template path does not | |
183 | refer to the root of a <literal>btrfs</literal> subvolume (or | |
184 | not even to a <literal>btrfs</literal> file system at all), | |
185 | the tree is copied, which can be substantially more | |
186 | time-consuming. Note that if this option is used the | |
187 | container's root directory (in contrast to the template | |
188 | directory!) must be located on a <literal>btrfs</literal> file | |
189 | system, so that the <literal>btrfs</literal> subvolume may be | |
190 | created. May not be specified together with | |
191 | <option>--image=</option> or | |
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192 | <option>--ephemeral</option>.</para> |
193 | ||
194 | <para>Note that this switch leaves host name, machine ID and | |
195 | all other settings that could identify the instance | |
196 | unmodified.</para></listitem> | |
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197 | </varlistentry> |
198 | ||
199 | <varlistentry> | |
200 | <term><option>-x</option></term> | |
201 | <term><option>--ephemeral</option></term> | |
202 | ||
203 | <listitem><para>If specified, the container is run with a | |
204 | temporary <literal>btrfs</literal> snapshot of its root | |
205 | directory (as configured with <option>--directory=</option>), | |
206 | that is removed immediately when the container terminates. | |
207 | This option is only supported if the root file system is | |
208 | <literal>btrfs</literal>. May not be specified together with | |
209 | <option>--image=</option> or | |
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210 | <option>--template=</option>.</para> |
211 | <para>Note that this switch leaves host name, machine ID and | |
212 | all other settings that could identify the instance | |
213 | unmodified.</para></listitem> | |
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214 | </varlistentry> |
215 | ||
216 | <varlistentry> | |
217 | <term><option>-i</option></term> | |
218 | <term><option>--image=</option></term> | |
219 | ||
220 | <listitem><para>Disk image to mount the root directory for the | |
221 | container from. Takes a path to a regular file or to a block | |
222 | device node. The file or block device must contain | |
223 | either:</para> | |
224 | ||
225 | <itemizedlist> | |
226 | <listitem><para>An MBR partition table with a single | |
227 | partition of type 0x83 that is marked | |
228 | bootable.</para></listitem> | |
229 | ||
230 | <listitem><para>A GUID partition table (GPT) with a single | |
231 | partition of type | |
232 | 0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem> | |
233 | ||
234 | <listitem><para>A GUID partition table (GPT) with a marked | |
235 | root partition which is mounted as the root directory of the | |
236 | container. Optionally, GPT images may contain a home and/or | |
237 | a server data partition which are mounted to the appropriate | |
238 | places in the container. All these partitions must be | |
239 | identified by the partition types defined by the <ulink | |
240 | url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable | |
241 | Partitions Specification</ulink>.</para></listitem> | |
242 | </itemizedlist> | |
243 | ||
244 | <para>Any other partitions, such as foreign partitions, swap | |
245 | partitions or EFI system partitions are not mounted. May not | |
246 | be specified together with <option>--directory=</option>, | |
247 | <option>--template=</option> or | |
248 | <option>--ephemeral</option>.</para></listitem> | |
249 | </varlistentry> | |
250 | ||
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251 | <varlistentry> |
252 | <term><option>-a</option></term> | |
253 | <term><option>--as-pid2</option></term> | |
254 | ||
255 | <listitem><para>Invoke the shell or specified program as process ID (PID) 2 instead of PID 1 (init). By | |
256 | default, if neither this option nor <option>--boot</option> is used, the selected binary is run as process with | |
257 | PID 1, a mode only suitable for programs that are aware of the special semantics that the process with PID 1 | |
258 | has on UNIX. For example, it needs to reap all processes reparented to it, and should implement | |
259 | <command>sysvinit</command> compatible signal handling (specifically: it needs to reboot on SIGINT, reexecute | |
260 | on SIGTERM, reload configuration on SIGHUP, and so on). With <option>--as-pid2</option> a minimal stub init | |
261 | process is run as PID 1 and the selected binary is executed as PID 2 (and hence does not need to implement any | |
262 | special semantics). The stub init process will reap processes as necessary and react appropriately to | |
263 | signals. It is recommended to use this mode to invoke arbitrary commands in containers, unless they have been | |
264 | modified to run correctly as PID 1. Or in other words: this switch should be used for pretty much all commands, | |
265 | except when the command refers to an init or shell implementation, as these are generally capable of running | |
4447e799 | 266 | correctly as PID 1. This option may not be combined with <option>--boot</option> or |
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267 | <option>--share-system</option>.</para> |
268 | </listitem> | |
269 | </varlistentry> | |
270 | ||
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271 | <varlistentry> |
272 | <term><option>-b</option></term> | |
273 | <term><option>--boot</option></term> | |
274 | ||
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275 | <listitem><para>Automatically search for an init binary and invoke it as PID 1, instead of a shell or a user |
276 | supplied program. If this option is used, arguments specified on the command line are used as arguments for the | |
277 | init binary. This option may not be combined with <option>--as-pid2</option> or | |
278 | <option>--share-system</option>.</para> | |
279 | ||
280 | <para>The following table explains the different modes of invocation and relationship to | |
281 | <option>--as-pid2</option> (see above):</para> | |
282 | ||
283 | <table> | |
284 | <title>Invocation Mode</title> | |
285 | <tgroup cols='2' align='left' colsep='1' rowsep='1'> | |
286 | <colspec colname="switch" /> | |
287 | <colspec colname="explanation" /> | |
288 | <thead> | |
289 | <row> | |
290 | <entry>Switch</entry> | |
291 | <entry>Explanation</entry> | |
292 | </row> | |
293 | </thead> | |
294 | <tbody> | |
295 | <row> | |
296 | <entry>Neither <option>--as-pid2</option> nor <option>--boot</option> specified</entry> | |
4447e799 | 297 | <entry>The passed parameters are interpreted as the command line, which is executed as PID 1 in the container.</entry> |
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298 | </row> |
299 | ||
300 | <row> | |
301 | <entry><option>--as-pid2</option> specified</entry> | |
4447e799 | 302 | <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> |
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303 | </row> |
304 | ||
305 | <row> | |
306 | <entry><option>--boot</option> specified</entry> | |
307 | <entry>An init binary as automatically searched and run as PID 1 in the container. The passed parameters are used as invocation parameters for this process.</entry> | |
308 | </row> | |
309 | ||
310 | </tbody> | |
311 | </tgroup> | |
312 | </table> | |
313 | </listitem> | |
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314 | </varlistentry> |
315 | ||
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316 | <varlistentry> |
317 | <term><option>--chdir=</option></term> | |
318 | ||
319 | <listitem><para>Change to the specified working directory before invoking the process in the container. Expects | |
320 | an absolute path in the container's file system namespace.</para></listitem> | |
321 | </varlistentry> | |
322 | ||
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323 | <varlistentry> |
324 | <term><option>-u</option></term> | |
325 | <term><option>--user=</option></term> | |
326 | ||
327 | <listitem><para>After transitioning into the container, change | |
328 | to the specified user-defined in the container's user | |
329 | database. Like all other systemd-nspawn features, this is not | |
330 | a security feature and provides protection against accidental | |
331 | destructive operations only.</para></listitem> | |
332 | </varlistentry> | |
333 | ||
334 | <varlistentry> | |
335 | <term><option>-M</option></term> | |
336 | <term><option>--machine=</option></term> | |
337 | ||
338 | <listitem><para>Sets the machine name for this container. This | |
339 | name may be used to identify this container during its runtime | |
340 | (for example in tools like | |
341 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
342 | and similar), and is used to initialize the container's | |
343 | hostname (which the container can choose to override, | |
344 | however). If not specified, the last component of the root | |
345 | directory path of the container is used, possibly suffixed | |
346 | with a random identifier in case <option>--ephemeral</option> | |
347 | mode is selected. If the root directory selected is the host's | |
348 | root directory the host's hostname is used as default | |
349 | instead.</para></listitem> | |
350 | </varlistentry> | |
351 | ||
352 | <varlistentry> | |
353 | <term><option>--uuid=</option></term> | |
354 | ||
355 | <listitem><para>Set the specified UUID for the container. The | |
356 | init system will initialize | |
357 | <filename>/etc/machine-id</filename> from this if this file is | |
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358 | not set yet. Note that this option takes effect only if |
359 | <filename>/etc/machine-id</filename> in the container is | |
360 | unpopulated.</para></listitem> | |
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361 | </varlistentry> |
362 | ||
363 | <varlistentry> | |
364 | <term><option>--slice=</option></term> | |
365 | ||
366 | <listitem><para>Make the container part of the specified | |
367 | slice, instead of the default | |
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368 | <filename>machine.slice</filename>. This is only applies if |
369 | the machine is run in its own scope unit, i.e. if | |
370 | <option>--keep-unit</option> is not used.</para> | |
371 | </listitem> | |
372 | </varlistentry> | |
373 | ||
374 | <varlistentry> | |
375 | <term><option>--property=</option></term> | |
376 | ||
377 | <listitem><para>Set a unit property on the scope unit to | |
378 | register for the machine. This only applies if the machine is | |
379 | run in its own scope unit, i.e. if | |
380 | <option>--keep-unit</option> is not used. Takes unit property | |
381 | assignments in the same format as <command>systemctl | |
382 | set-property</command>. This is useful to set memory limits | |
383 | and similar for machines.</para> | |
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384 | </listitem> |
385 | </varlistentry> | |
386 | ||
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387 | <varlistentry> |
388 | <term><option>--private-users=</option></term> | |
389 | ||
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390 | <listitem><para>Controls user namespacing. If enabled, the container will run with its own private set of UNIX |
391 | user and group ids (UIDs and GIDs). This involves mapping the private UIDs/GIDs used in the container (starting | |
392 | with the container's root user 0 and up) to a range of UIDs/GIDs on the host that are not used for other | |
393 | purposes (usually in the range beyond the host's UID/GID 65536). The parameter may be specified as follows:</para> | |
394 | ||
395 | <orderedlist> | |
396 | <listitem><para>The value <literal>no</literal> turns off user namespacing. This is the default.</para></listitem> | |
397 | ||
398 | <listitem><para>The value <literal>yes</literal> (or the omission of a parameter) turns on user | |
399 | namespacing. The UID/GID range to use is determined automatically from the file ownership of the root | |
400 | directory of the container's directory tree. To use this option, make sure to prepare the directory tree in | |
401 | advance, and ensure that all files and directories in it are owned by UIDs/GIDs in the range you'd like to | |
402 | use. Also, make sure that used file ACLs exclusively reference UIDs/GIDs in the appropriate range. If this | |
403 | mode is used the number of UIDs/GIDs assigned to the container for use is 65536, and the UID/GID of the | |
404 | root directory must be a multiple of 65536.</para></listitem> | |
405 | ||
406 | <listitem><para>The value "pick" turns on user namespacing. In this case the UID/GID range is automatically | |
407 | chosen. As first step, the file owner of the root directory of the container's directory tree is read, and it | |
408 | is checked that it is currently not used by the system otherwise (in particular, that no other container is | |
409 | using it). If this check is successful, the UID/GID range determined this way is used, similar to the | |
410 | behaviour if "yes" is specified. If the check is not successful (and thus the UID/GID range indicated in the | |
411 | root directory's file owner is already used elsewhere) a new – currently unused – UID/GID range of 65536 | |
412 | UIDs/GIDs is randomly chosen between the host UID/GIDs of 524288 and 1878982656, always starting at a | |
413 | multiple of 65536. This setting implies <option>--private-users-chown</option> (see below), which has the | |
414 | effect that the files and directories in the container's directory tree will be owned by the appropriate | |
415 | users of the range picked. Using this option makes user namespace behaviour fully automatic. Note that the | |
416 | first invocation of a previously unused container image might result in picking a new UID/GID range for it, | |
417 | and thus in the (possibly expensive) file ownership adjustment operation. However, subsequent invocations of | |
418 | the container will be cheap (unless of course the picked UID/GID range is assigned to a different use by | |
419 | then).</para></listitem> | |
420 | ||
421 | <listitem><para>Finally if one or two colon-separated numeric parameters are specified, user namespacing is | |
422 | turned on, too. The first parameter specifies the first host UID/GID to assign to the container, the second | |
423 | parameter specifies the number of host UIDs/GIDs to assign to the container. If the second parameter is | |
424 | omitted, 65536 UIDs/GIDs are assigned.</para></listitem> | |
425 | </orderedlist> | |
426 | ||
427 | <para>It is recommended to assign at least 65536 UIDs/GIDs to each container, so that the usable UID/GID range in the | |
428 | container covers 16 bit. For best security, do not assign overlapping UID/GID ranges to multiple containers. It is | |
429 | hence a good idea to use the upper 16 bit of the host 32-bit UIDs/GIDs as container identifier, while the lower 16 | |
430 | bit encode the container UID/GID used. This is in fact the behaviour enforced by the | |
431 | <option>--private-users=pick</option> option.</para> | |
432 | ||
433 | <para>When user namespaces are used, the GID range assigned to each container is always chosen identical to the | |
434 | UID range.</para> | |
435 | ||
436 | <para>In most cases, using <option>--private-users=pick</option> is the recommended option as it enhances | |
437 | container security massively and operates fully automatically in most cases.</para> | |
438 | ||
439 | <para>Note that the picked UID/GID range is not written to <filename>/etc/passwd</filename> or | |
440 | <filename>/etc/group</filename>. In fact, the allocation of the range is not stored persistently anywhere, | |
441 | except in the file ownership of the files and directories of the container.</para></listitem> | |
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442 | </varlistentry> |
443 | ||
d2e5535f LP |
444 | <varlistentry> |
445 | <term><option>-U</option></term> | |
446 | ||
ccabee0d LP |
447 | <listitem><para>If the kernel supports the user namespaces feature, equivalent to |
448 | <option>--private-users=pick</option>, otherwise equivalent to | |
449 | <option>--private-users=no</option>.</para></listitem> | |
d2e5535f LP |
450 | </varlistentry> |
451 | ||
452 | <varlistentry> | |
453 | <term><option>--private-users-chown</option></term> | |
454 | ||
455 | <listitem><para>If specified, all files and directories in the container's directory tree will adjusted so that | |
456 | they are owned to the appropriate UIDs/GIDs selected for the container (see above). This operation is | |
457 | potentially expensive, as it involves descending and iterating through the full directory tree of the | |
458 | container. Besides actual file ownership, file ACLs are adjusted as well.</para> | |
459 | ||
460 | <para>This option is implied if <option>--private-users=pick</option> is used. This option has no effect if | |
461 | user namespacing is not used.</para></listitem> | |
462 | </varlistentry> | |
03cfe0d5 | 463 | |
798d3a52 ZJS |
464 | <varlistentry> |
465 | <term><option>--private-network</option></term> | |
466 | ||
467 | <listitem><para>Disconnect networking of the container from | |
468 | the host. This makes all network interfaces unavailable in the | |
469 | container, with the exception of the loopback device and those | |
470 | specified with <option>--network-interface=</option> and | |
471 | configured with <option>--network-veth</option>. If this | |
472 | option is specified, the CAP_NET_ADMIN capability will be | |
473 | added to the set of capabilities the container retains. The | |
474 | latter may be disabled by using | |
475 | <option>--drop-capability=</option>.</para></listitem> | |
476 | </varlistentry> | |
477 | ||
478 | <varlistentry> | |
479 | <term><option>--network-interface=</option></term> | |
480 | ||
481 | <listitem><para>Assign the specified network interface to the | |
482 | container. This will remove the specified interface from the | |
483 | calling namespace and place it in the container. When the | |
484 | container terminates, it is moved back to the host namespace. | |
485 | Note that <option>--network-interface=</option> implies | |
486 | <option>--private-network</option>. This option may be used | |
487 | more than once to add multiple network interfaces to the | |
488 | container.</para></listitem> | |
489 | </varlistentry> | |
490 | ||
491 | <varlistentry> | |
492 | <term><option>--network-macvlan=</option></term> | |
493 | ||
494 | <listitem><para>Create a <literal>macvlan</literal> interface | |
495 | of the specified Ethernet network interface and add it to the | |
496 | container. A <literal>macvlan</literal> interface is a virtual | |
497 | interface that adds a second MAC address to an existing | |
498 | physical Ethernet link. The interface in the container will be | |
499 | named after the interface on the host, prefixed with | |
500 | <literal>mv-</literal>. Note that | |
501 | <option>--network-macvlan=</option> implies | |
502 | <option>--private-network</option>. This option may be used | |
503 | more than once to add multiple network interfaces to the | |
504 | container.</para></listitem> | |
505 | </varlistentry> | |
506 | ||
507 | <varlistentry> | |
508 | <term><option>--network-ipvlan=</option></term> | |
509 | ||
510 | <listitem><para>Create an <literal>ipvlan</literal> interface | |
511 | of the specified Ethernet network interface and add it to the | |
512 | container. An <literal>ipvlan</literal> interface is a virtual | |
513 | interface, similar to a <literal>macvlan</literal> interface, | |
514 | which uses the same MAC address as the underlying interface. | |
515 | The interface in the container will be named after the | |
516 | interface on the host, prefixed with <literal>iv-</literal>. | |
517 | Note that <option>--network-ipvlan=</option> implies | |
518 | <option>--private-network</option>. This option may be used | |
519 | more than once to add multiple network interfaces to the | |
520 | container.</para></listitem> | |
521 | </varlistentry> | |
522 | ||
523 | <varlistentry> | |
524 | <term><option>-n</option></term> | |
525 | <term><option>--network-veth</option></term> | |
526 | ||
5e7423ff LP |
527 | <listitem><para>Create a virtual Ethernet link (<literal>veth</literal>) between host and container. The host |
528 | side of the Ethernet link will be available as a network interface named after the container's name (as | |
529 | specified with <option>--machine=</option>), prefixed with <literal>ve-</literal>. The container side of the | |
530 | Ethernet link will be named <literal>host0</literal>. The <option>--network-veth</option> option implies | |
531 | <option>--private-network</option>.</para> | |
532 | ||
533 | <para>Note that | |
534 | <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
535 | includes by default a network file <filename>/usr/lib/systemd/network/80-container-ve.network</filename> | |
536 | matching the host-side interfaces created this way, which contains settings to enable automatic address | |
537 | provisioning on the created virtual link via DHCP, as well as automatic IP routing onto the host's external | |
538 | network interfaces. It also contains <filename>/usr/lib/systemd/network/80-container-host0.network</filename> | |
539 | matching the container-side interface created this way, containing settings to enable client side address | |
540 | assignment via DHCP. In case <filename>systemd-networkd</filename> is running on both the host and inside the | |
541 | container, automatic IP communication from the container to the host is thus available, with further | |
542 | connectivity to the external network.</para> | |
543 | </listitem> | |
798d3a52 ZJS |
544 | </varlistentry> |
545 | ||
f6d6bad1 LP |
546 | <varlistentry> |
547 | <term><option>--network-veth-extra=</option></term> | |
548 | ||
549 | <listitem><para>Adds an additional virtual Ethernet link | |
550 | between host and container. Takes a colon-separated pair of | |
551 | host interface name and container interface name. The latter | |
552 | may be omitted in which case the container and host sides will | |
553 | be assigned the same name. This switch is independent of | |
ccddd104 | 554 | <option>--network-veth</option>, and — in contrast — may be |
f6d6bad1 LP |
555 | used multiple times, and allows configuration of the network |
556 | interface names. Note that <option>--network-bridge=</option> | |
557 | has no effect on interfaces created with | |
558 | <option>--network-veth-extra=</option>.</para></listitem> | |
559 | </varlistentry> | |
560 | ||
798d3a52 ZJS |
561 | <varlistentry> |
562 | <term><option>--network-bridge=</option></term> | |
563 | ||
5e7423ff LP |
564 | <listitem><para>Adds the host side of the Ethernet link created with <option>--network-veth</option> to the |
565 | specified Ethernet bridge interface. Expects a valid network interface name of a bridge device as | |
566 | argument. Note that <option>--network-bridge=</option> implies <option>--network-veth</option>. If this option | |
567 | is used, the host side of the Ethernet link will use the <literal>vb-</literal> prefix instead of | |
798d3a52 ZJS |
568 | <literal>ve-</literal>.</para></listitem> |
569 | </varlistentry> | |
570 | ||
938d2579 LP |
571 | <varlistentry> |
572 | <term><option>--network-zone=</option></term> | |
573 | ||
574 | <listitem><para>Creates a virtual Ethernet link (<literal>veth</literal>) to the container and adds it to an | |
575 | automatically managed Ethernet bridge interface. The bridge interface is named after the passed argument, | |
576 | prefixed with <literal>vz-</literal>. The bridge interface is automatically created when the first container | |
577 | configured for its name is started, and is automatically removed when the last container configured for its | |
578 | name exits. Hence, each bridge interface configured this way exists only as long as there's at least one | |
579 | container referencing it running. This option is very similar to <option>--network-bridge=</option>, besides | |
580 | this automatic creation/removal of the bridge device.</para> | |
581 | ||
582 | <para>This setting makes it easy to place multiple related containers on a common, virtual Ethernet-based | |
583 | broadcast domain, here called a "zone". Each container may only be part of one zone, but each zone may contain | |
584 | any number of containers. Each zone is referenced by its name. Names may be chosen freely (as long as they form | |
585 | valid network interface names when prefixed with <literal>vz-</literal>), and it is sufficient to pass the same | |
586 | name to the <option>--network-zones=</option> switch of the various concurrently running containers to join | |
587 | them in one zone.</para> | |
588 | ||
589 | <para>Note that | |
590 | <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
591 | includes by default a network file <filename>/usr/lib/systemd/network/80-container-vz.network</filename> | |
592 | matching the bridge interfaces created this way, which contains settings to enable automatic address | |
593 | provisioning on the created virtual network via DHCP, as well as automatic IP routing onto the host's external | |
594 | network interfaces. Using <option>--network-zone=</option> is hence in most cases fully automatic and | |
595 | sufficient to connect multiple local containers in a joined broadcast domain to the host, with further | |
596 | connectivity to the external network.</para> | |
597 | </listitem> | |
598 | </varlistentry> | |
599 | ||
798d3a52 ZJS |
600 | <varlistentry> |
601 | <term><option>-p</option></term> | |
602 | <term><option>--port=</option></term> | |
603 | ||
604 | <listitem><para>If private networking is enabled, maps an IP | |
605 | port on the host onto an IP port on the container. Takes a | |
606 | protocol specifier (either <literal>tcp</literal> or | |
607 | <literal>udp</literal>), separated by a colon from a host port | |
608 | number in the range 1 to 65535, separated by a colon from a | |
609 | container port number in the range from 1 to 65535. The | |
610 | protocol specifier and its separating colon may be omitted, in | |
611 | which case <literal>tcp</literal> is assumed. The container | |
7c918141 | 612 | port number and its colon may be omitted, in which case the |
798d3a52 | 613 | same port as the host port is implied. This option is only |
a8eaaee7 | 614 | supported if private networking is used, such as with |
938d2579 | 615 | <option>--network-veth</option>, <option>--network-zone=</option> |
798d3a52 ZJS |
616 | <option>--network-bridge=</option>.</para></listitem> |
617 | </varlistentry> | |
618 | ||
619 | <varlistentry> | |
620 | <term><option>-Z</option></term> | |
621 | <term><option>--selinux-context=</option></term> | |
622 | ||
623 | <listitem><para>Sets the SELinux security context to be used | |
624 | to label processes in the container.</para> | |
625 | </listitem> | |
626 | </varlistentry> | |
627 | ||
628 | <varlistentry> | |
629 | <term><option>-L</option></term> | |
630 | <term><option>--selinux-apifs-context=</option></term> | |
631 | ||
632 | <listitem><para>Sets the SELinux security context to be used | |
633 | to label files in the virtual API file systems in the | |
634 | container.</para> | |
635 | </listitem> | |
636 | </varlistentry> | |
637 | ||
638 | <varlistentry> | |
639 | <term><option>--capability=</option></term> | |
640 | ||
641 | <listitem><para>List one or more additional capabilities to | |
642 | grant the container. Takes a comma-separated list of | |
643 | capability names, see | |
644 | <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
645 | for more information. Note that the following capabilities | |
646 | will be granted in any way: CAP_CHOWN, CAP_DAC_OVERRIDE, | |
647 | CAP_DAC_READ_SEARCH, CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER, | |
648 | CAP_KILL, CAP_LEASE, CAP_LINUX_IMMUTABLE, | |
649 | CAP_NET_BIND_SERVICE, CAP_NET_BROADCAST, CAP_NET_RAW, | |
650 | CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, CAP_SETUID, | |
651 | CAP_SYS_ADMIN, CAP_SYS_CHROOT, CAP_SYS_NICE, CAP_SYS_PTRACE, | |
652 | CAP_SYS_TTY_CONFIG, CAP_SYS_RESOURCE, CAP_SYS_BOOT, | |
653 | CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN is | |
654 | retained if <option>--private-network</option> is specified. | |
655 | If the special value <literal>all</literal> is passed, all | |
656 | capabilities are retained.</para></listitem> | |
657 | </varlistentry> | |
658 | ||
659 | <varlistentry> | |
660 | <term><option>--drop-capability=</option></term> | |
661 | ||
662 | <listitem><para>Specify one or more additional capabilities to | |
663 | drop for the container. This allows running the container with | |
664 | fewer capabilities than the default (see | |
665 | above).</para></listitem> | |
666 | </varlistentry> | |
667 | ||
c6c8f6e2 LP |
668 | <varlistentry> |
669 | <term><option>--kill-signal=</option></term> | |
670 | ||
671 | <listitem><para>Specify the process signal to send to the | |
672 | container's PID 1 when nspawn itself receives SIGTERM, in | |
673 | order to trigger an orderly shutdown of the | |
674 | container. Defaults to SIGRTMIN+3 if <option>--boot</option> | |
675 | is used (on systemd-compatible init systems SIGRTMIN+3 | |
b3969f73 PA |
676 | triggers an orderly shutdown). For a list of valid signals, see |
677 | <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> | |
c6c8f6e2 LP |
678 | </varlistentry> |
679 | ||
798d3a52 ZJS |
680 | <varlistentry> |
681 | <term><option>--link-journal=</option></term> | |
682 | ||
683 | <listitem><para>Control whether the container's journal shall | |
684 | be made visible to the host system. If enabled, allows viewing | |
685 | the container's journal files from the host (but not vice | |
686 | versa). Takes one of <literal>no</literal>, | |
687 | <literal>host</literal>, <literal>try-host</literal>, | |
688 | <literal>guest</literal>, <literal>try-guest</literal>, | |
689 | <literal>auto</literal>. If <literal>no</literal>, the journal | |
690 | is not linked. If <literal>host</literal>, the journal files | |
691 | are stored on the host file system (beneath | |
692 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
693 | and the subdirectory is bind-mounted into the container at the | |
694 | same location. If <literal>guest</literal>, the journal files | |
695 | are stored on the guest file system (beneath | |
696 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
697 | and the subdirectory is symlinked into the host at the same | |
698 | location. <literal>try-host</literal> and | |
699 | <literal>try-guest</literal> do the same but do not fail if | |
700 | the host does not have persistent journalling enabled. If | |
701 | <literal>auto</literal> (the default), and the right | |
702 | subdirectory of <filename>/var/log/journal</filename> exists, | |
703 | it will be bind mounted into the container. If the | |
704 | subdirectory does not exist, no linking is performed. | |
705 | Effectively, booting a container once with | |
706 | <literal>guest</literal> or <literal>host</literal> will link | |
707 | the journal persistently if further on the default of | |
708 | <literal>auto</literal> is used.</para></listitem> | |
709 | </varlistentry> | |
710 | ||
711 | <varlistentry> | |
712 | <term><option>-j</option></term> | |
713 | ||
714 | <listitem><para>Equivalent to | |
715 | <option>--link-journal=try-guest</option>.</para></listitem> | |
716 | </varlistentry> | |
717 | ||
718 | <varlistentry> | |
719 | <term><option>--read-only</option></term> | |
720 | ||
721 | <listitem><para>Mount the root file system read-only for the | |
722 | container.</para></listitem> | |
723 | </varlistentry> | |
724 | ||
725 | <varlistentry> | |
726 | <term><option>--bind=</option></term> | |
727 | <term><option>--bind-ro=</option></term> | |
728 | ||
729 | <listitem><para>Bind mount a file or directory from the host | |
b938cb90 | 730 | into the container. Takes one of: a path argument — in which |
798d3a52 | 731 | case the specified path will be mounted from the host to the |
b938cb90 JE |
732 | same path in the container —, or a colon-separated pair of |
733 | paths — in which case the first specified path is the source | |
798d3a52 | 734 | in the host, and the second path is the destination in the |
b938cb90 JE |
735 | container —, or a colon-separated triple of source path, |
736 | destination path and mount options. Mount options are | |
737 | comma-separated and currently, only "rbind" and "norbind" | |
738 | are allowed. Defaults to "rbind". Backslash escapes are interpreted, so | |
8ef24e7a RM |
739 | <literal>\:</literal> may be used to embed colons in either path. |
740 | This option may be specified multiple times for | |
64b282ef LP |
741 | creating multiple independent bind mount points. The |
742 | <option>--bind-ro=</option> option creates read-only bind | |
743 | mounts.</para></listitem> | |
798d3a52 ZJS |
744 | </varlistentry> |
745 | ||
746 | <varlistentry> | |
747 | <term><option>--tmpfs=</option></term> | |
748 | ||
749 | <listitem><para>Mount a tmpfs file system into the container. | |
750 | Takes a single absolute path argument that specifies where to | |
751 | mount the tmpfs instance to (in which case the directory | |
752 | access mode will be chosen as 0755, owned by root/root), or | |
753 | optionally a colon-separated pair of path and mount option | |
b938cb90 | 754 | string that is used for mounting (in which case the kernel |
798d3a52 ZJS |
755 | default for access mode and owner will be chosen, unless |
756 | otherwise specified). This option is particularly useful for | |
757 | mounting directories such as <filename>/var</filename> as | |
758 | tmpfs, to allow state-less systems, in particular when | |
ffcd3e89 | 759 | combined with <option>--read-only</option>. |
b938cb90 | 760 | Backslash escapes are interpreted in the path, so |
ffcd3e89 RM |
761 | <literal>\:</literal> may be used to embed colons in the path. |
762 | </para></listitem> | |
798d3a52 ZJS |
763 | </varlistentry> |
764 | ||
5a8af538 LP |
765 | <varlistentry> |
766 | <term><option>--overlay=</option></term> | |
767 | <term><option>--overlay-ro=</option></term> | |
768 | ||
769 | <listitem><para>Combine multiple directory trees into one | |
770 | overlay file system and mount it into the container. Takes a | |
771 | list of colon-separated paths to the directory trees to | |
772 | combine and the destination mount point.</para> | |
773 | ||
2eadf91c RM |
774 | <para>Backslash escapes are interpreted in the paths, so |
775 | <literal>\:</literal> may be used to embed colons in the paths. | |
776 | </para> | |
777 | ||
5a8af538 LP |
778 | <para>If three or more paths are specified, then the last |
779 | specified path is the destination mount point in the | |
780 | container, all paths specified before refer to directory trees | |
781 | on the host and are combined in the specified order into one | |
782 | overlay file system. The left-most path is hence the lowest | |
783 | directory tree, the second-to-last path the highest directory | |
784 | tree in the stacking order. If <option>--overlay-ro=</option> | |
b938cb90 | 785 | is used instead of <option>--overlay=</option>, a read-only |
5a8af538 | 786 | overlay file system is created. If a writable overlay file |
b938cb90 | 787 | system is created, all changes made to it are written to the |
5a8af538 LP |
788 | highest directory tree in the stacking order, i.e. the |
789 | second-to-last specified.</para> | |
790 | ||
791 | <para>If only two paths are specified, then the second | |
792 | specified path is used both as the top-level directory tree in | |
793 | the stacking order as seen from the host, as well as the mount | |
794 | point for the overlay file system in the container. At least | |
795 | two paths have to be specified.</para> | |
796 | ||
797 | <para>For details about overlay file systems, see <ulink | |
798 | url="https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt">overlayfs.txt</ulink>. Note | |
799 | that the semantics of overlay file systems are substantially | |
800 | different from normal file systems, in particular regarding | |
801 | reported device and inode information. Device and inode | |
802 | information may change for a file while it is being written | |
803 | to, and processes might see out-of-date versions of files at | |
804 | times. Note that this switch automatically derives the | |
805 | <literal>workdir=</literal> mount option for the overlay file | |
806 | system from the top-level directory tree, making it a sibling | |
807 | of it. It is hence essential that the top-level directory tree | |
808 | is not a mount point itself (since the working directory must | |
809 | be on the same file system as the top-most directory | |
810 | tree). Also note that the <literal>lowerdir=</literal> mount | |
811 | option receives the paths to stack in the opposite order of | |
812 | this switch.</para></listitem> | |
813 | </varlistentry> | |
814 | ||
798d3a52 | 815 | <varlistentry> |
a5f1cb3b ZJS |
816 | <term><option>-E <replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term> |
817 | <term><option>--setenv=<replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term> | |
798d3a52 ZJS |
818 | |
819 | <listitem><para>Specifies an environment variable assignment | |
820 | to pass to the init process in the container, in the format | |
821 | <literal>NAME=VALUE</literal>. This may be used to override | |
822 | the default variables or to set additional variables. This | |
823 | parameter may be used more than once.</para></listitem> | |
824 | </varlistentry> | |
825 | ||
826 | <varlistentry> | |
827 | <term><option>--share-system</option></term> | |
828 | ||
829 | <listitem><para>Allows the container to share certain system | |
830 | facilities with the host. More specifically, this turns off | |
831 | PID namespacing, UTS namespacing and IPC namespacing, and thus | |
832 | allows the guest to see and interact more easily with | |
833 | processes outside of the container. Note that using this | |
834 | option makes it impossible to start up a full Operating System | |
835 | in the container, as an init system cannot operate in this | |
836 | mode. It is only useful to run specific programs or | |
837 | applications this way, without involving an init system in the | |
838 | container. This option implies <option>--register=no</option>. | |
839 | This option may not be combined with | |
840 | <option>--boot</option>.</para></listitem> | |
841 | </varlistentry> | |
842 | ||
843 | <varlistentry> | |
844 | <term><option>--register=</option></term> | |
845 | ||
846 | <listitem><para>Controls whether the container is registered | |
847 | with | |
848 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
a8eaaee7 | 849 | Takes a boolean argument, which defaults to <literal>yes</literal>. |
798d3a52 ZJS |
850 | This option should be enabled when the container runs a full |
851 | Operating System (more specifically: an init system), and is | |
852 | useful to ensure that the container is accessible via | |
853 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
854 | and shown by tools such as | |
855 | <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. | |
856 | If the container does not run an init system, it is | |
857 | recommended to set this option to <literal>no</literal>. Note | |
858 | that <option>--share-system</option> implies | |
859 | <option>--register=no</option>. </para></listitem> | |
860 | </varlistentry> | |
861 | ||
862 | <varlistentry> | |
863 | <term><option>--keep-unit</option></term> | |
864 | ||
865 | <listitem><para>Instead of creating a transient scope unit to | |
866 | run the container in, simply register the service or scope | |
867 | unit <command>systemd-nspawn</command> has been invoked in | |
868 | with | |
869 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
870 | This has no effect if <option>--register=no</option> is used. | |
871 | This switch should be used if | |
872 | <command>systemd-nspawn</command> is invoked from within a | |
873 | service unit, and the service unit's sole purpose is to run a | |
874 | single <command>systemd-nspawn</command> container. This | |
875 | option is not available if run from a user | |
876 | session.</para></listitem> | |
877 | </varlistentry> | |
878 | ||
879 | <varlistentry> | |
880 | <term><option>--personality=</option></term> | |
881 | ||
882 | <listitem><para>Control the architecture ("personality") | |
883 | reported by | |
3ba3a79d | 884 | <citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> |
798d3a52 ZJS |
885 | in the container. Currently, only <literal>x86</literal> and |
886 | <literal>x86-64</literal> are supported. This is useful when | |
887 | running a 32-bit container on a 64-bit host. If this setting | |
888 | is not used, the personality reported in the container is the | |
889 | same as the one reported on the host.</para></listitem> | |
890 | </varlistentry> | |
891 | ||
892 | <varlistentry> | |
893 | <term><option>-q</option></term> | |
894 | <term><option>--quiet</option></term> | |
895 | ||
896 | <listitem><para>Turns off any status output by the tool | |
897 | itself. When this switch is used, the only output from nspawn | |
898 | will be the console output of the container OS | |
899 | itself.</para></listitem> | |
900 | </varlistentry> | |
901 | ||
902 | <varlistentry> | |
f757855e LP |
903 | <term><option>--volatile</option></term> |
904 | <term><option>--volatile=</option><replaceable>MODE</replaceable></term> | |
798d3a52 ZJS |
905 | |
906 | <listitem><para>Boots the container in volatile mode. When no | |
907 | mode parameter is passed or when mode is specified as | |
b938cb90 | 908 | <option>yes</option>, full volatile mode is enabled. This |
a8eaaee7 | 909 | means the root directory is mounted as a mostly unpopulated |
798d3a52 | 910 | <literal>tmpfs</literal> instance, and |
cd72d204 JE |
911 | <filename>/usr</filename> from the OS tree is mounted into it |
912 | in read-only mode (the system thus starts up with read-only OS | |
798d3a52 ZJS |
913 | resources, but pristine state and configuration, any changes |
914 | to the either are lost on shutdown). When the mode parameter | |
b938cb90 | 915 | is specified as <option>state</option>, the OS tree is |
798d3a52 | 916 | mounted read-only, but <filename>/var</filename> is mounted as |
a8eaaee7 | 917 | a <literal>tmpfs</literal> instance into it (the system thus |
798d3a52 | 918 | starts up with read-only OS resources and configuration, but |
a8eaaee7 | 919 | pristine state, and any changes to the latter are lost on |
798d3a52 | 920 | shutdown). When the mode parameter is specified as |
b938cb90 | 921 | <option>no</option> (the default), the whole OS tree is made |
798d3a52 ZJS |
922 | available writable.</para> |
923 | ||
f757855e LP |
924 | <para>Note that setting this to <option>yes</option> or |
925 | <option>state</option> will only work correctly with | |
798d3a52 ZJS |
926 | operating systems in the container that can boot up with only |
927 | <filename>/usr</filename> mounted, and are able to populate | |
928 | <filename>/var</filename> automatically, as | |
929 | needed.</para></listitem> | |
930 | </varlistentry> | |
931 | ||
f757855e LP |
932 | <varlistentry> |
933 | <term><option>--settings=</option><replaceable>MODE</replaceable></term> | |
934 | ||
935 | <listitem><para>Controls whether | |
936 | <command>systemd-nspawn</command> shall search for and use | |
937 | additional per-container settings from | |
938 | <filename>.nspawn</filename> files. Takes a boolean or the | |
939 | special values <option>override</option> or | |
940 | <option>trusted</option>.</para> | |
941 | ||
b938cb90 | 942 | <para>If enabled (the default), a settings file named after the |
f757855e LP |
943 | machine (as specified with the <option>--machine=</option> |
944 | setting, or derived from the directory or image file name) | |
945 | with the suffix <filename>.nspawn</filename> is searched in | |
946 | <filename>/etc/systemd/nspawn/</filename> and | |
947 | <filename>/run/systemd/nspawn/</filename>. If it is found | |
948 | there, its settings are read and used. If it is not found | |
b938cb90 | 949 | there, it is subsequently searched in the same directory as the |
f757855e | 950 | image file or in the immediate parent of the root directory of |
b938cb90 | 951 | the container. In this case, if the file is found, its settings |
f757855e | 952 | will be also read and used, but potentially unsafe settings |
b938cb90 | 953 | are ignored. Note that in both these cases, settings on the |
4f76ef04 | 954 | command line take precedence over the corresponding settings |
f757855e LP |
955 | from loaded <filename>.nspawn</filename> files, if both are |
956 | specified. Unsafe settings are considered all settings that | |
957 | elevate the container's privileges or grant access to | |
958 | additional resources such as files or directories of the | |
959 | host. For details about the format and contents of | |
b938cb90 | 960 | <filename>.nspawn</filename> files, consult |
f757855e LP |
961 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> |
962 | ||
b938cb90 JE |
963 | <para>If this option is set to <option>override</option>, the |
964 | file is searched, read and used the same way, however, the order of | |
f757855e LP |
965 | precedence is reversed: settings read from the |
966 | <filename>.nspawn</filename> file will take precedence over | |
967 | the corresponding command line options, if both are | |
968 | specified.</para> | |
969 | ||
b938cb90 | 970 | <para>If this option is set to <option>trusted</option>, the |
f757855e | 971 | file is searched, read and used the same way, but regardless |
a8eaaee7 | 972 | of being found in <filename>/etc/systemd/nspawn/</filename>, |
f757855e LP |
973 | <filename>/run/systemd/nspawn/</filename> or next to the image |
974 | file or container root directory, all settings will take | |
b938cb90 | 975 | effect, however, command line arguments still take precedence |
f757855e LP |
976 | over corresponding settings.</para> |
977 | ||
b938cb90 | 978 | <para>If disabled, no <filename>.nspawn</filename> file is read |
f757855e LP |
979 | and no settings except the ones on the command line are in |
980 | effect.</para></listitem> | |
981 | </varlistentry> | |
982 | ||
798d3a52 ZJS |
983 | <xi:include href="standard-options.xml" xpointer="help" /> |
984 | <xi:include href="standard-options.xml" xpointer="version" /> | |
985 | </variablelist> | |
986 | ||
987 | </refsect1> | |
988 | ||
989 | <refsect1> | |
990 | <title>Examples</title> | |
991 | ||
992 | <example> | |
993 | <title>Download a Fedora image and start a shell in it</title> | |
994 | ||
995 | <programlisting># machinectl pull-raw --verify=no http://ftp.halifax.rwth-aachen.de/fedora/linux/releases/21/Cloud/Images/x86_64/Fedora-Cloud-Base-20141203-21.x86_64.raw.xz | |
e0ea94c1 LP |
996 | # systemd-nspawn -M Fedora-Cloud-Base-20141203-21</programlisting> |
997 | ||
798d3a52 ZJS |
998 | <para>This downloads an image using |
999 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1000 | and opens a shell in it.</para> | |
1001 | </example> | |
e0ea94c1 | 1002 | |
798d3a52 ZJS |
1003 | <example> |
1004 | <title>Build and boot a minimal Fedora distribution in a container</title> | |
8f7a3c14 | 1005 | |
09c76ef6 | 1006 | <programlisting># dnf -y --releasever=23 --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora --enablerepo=updates install systemd passwd dnf fedora-release vim-minimal |
2b3987a8 | 1007 | # systemd-nspawn -bD /srv/mycontainer</programlisting> |
8f7a3c14 | 1008 | |
798d3a52 ZJS |
1009 | <para>This installs a minimal Fedora distribution into the |
1010 | directory <filename noindex='true'>/srv/mycontainer/</filename> | |
1011 | and then boots an OS in a namespace container in it.</para> | |
1012 | </example> | |
8f7a3c14 | 1013 | |
798d3a52 ZJS |
1014 | <example> |
1015 | <title>Spawn a shell in a container of a minimal Debian unstable distribution</title> | |
8f7a3c14 | 1016 | |
798d3a52 | 1017 | <programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/ |
25f5971b | 1018 | # systemd-nspawn -D ~/debian-tree/</programlisting> |
8f7a3c14 | 1019 | |
798d3a52 ZJS |
1020 | <para>This installs a minimal Debian unstable distribution into |
1021 | the directory <filename>~/debian-tree/</filename> and then | |
1022 | spawns a shell in a namespace container in it.</para> | |
1023 | </example> | |
8f7a3c14 | 1024 | |
798d3a52 ZJS |
1025 | <example> |
1026 | <title>Boot a minimal Arch Linux distribution in a container</title> | |
68562936 | 1027 | |
798d3a52 | 1028 | <programlisting># pacstrap -c -d ~/arch-tree/ base |
68562936 WG |
1029 | # systemd-nspawn -bD ~/arch-tree/</programlisting> |
1030 | ||
ff9b60f3 | 1031 | <para>This installs a minimal Arch Linux distribution into the |
798d3a52 ZJS |
1032 | directory <filename>~/arch-tree/</filename> and then boots an OS |
1033 | in a namespace container in it.</para> | |
1034 | </example> | |
68562936 | 1035 | |
798d3a52 ZJS |
1036 | <example> |
1037 | <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title> | |
f9f4dd51 | 1038 | |
798d3a52 | 1039 | <programlisting># systemd-nspawn -D / -xb</programlisting> |
f9f4dd51 | 1040 | |
798d3a52 ZJS |
1041 | <para>This runs a copy of the host system in a |
1042 | <literal>btrfs</literal> snapshot which is removed immediately | |
1043 | when the container exits. All file system changes made during | |
1044 | runtime will be lost on shutdown, hence.</para> | |
1045 | </example> | |
f9f4dd51 | 1046 | |
798d3a52 ZJS |
1047 | <example> |
1048 | <title>Run a container with SELinux sandbox security contexts</title> | |
a8828ed9 | 1049 | |
798d3a52 | 1050 | <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container |
a8828ed9 | 1051 | # systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh</programlisting> |
798d3a52 ZJS |
1052 | </example> |
1053 | </refsect1> | |
1054 | ||
1055 | <refsect1> | |
1056 | <title>Exit status</title> | |
1057 | ||
1058 | <para>The exit code of the program executed in the container is | |
1059 | returned.</para> | |
1060 | </refsect1> | |
1061 | ||
1062 | <refsect1> | |
1063 | <title>See Also</title> | |
1064 | <para> | |
1065 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
f757855e | 1066 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
798d3a52 ZJS |
1067 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
1068 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
798d3a52 ZJS |
1069 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
1070 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
1071 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1072 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
3ba3a79d | 1073 | <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
798d3a52 ZJS |
1074 | </para> |
1075 | </refsect1> | |
8f7a3c14 LP |
1076 | |
1077 | </refentry> |