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1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
798d3a52 | 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" |
798d3a52 ZJS |
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> | |
61 | <arg choice="plain">-b</arg> | |
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 | |
87 | <command>systemd-nspawn</command> is not suitable for secure | |
88 | container setups. Many of the security features may be | |
89 | circumvented and are hence primarily useful to avoid accidental | |
90 | changes to the host system from the container. The intended use of | |
91 | this program is debugging and testing as well as building of | |
92 | packages, distributions and software involved with boot and | |
93 | systems management.</para> | |
94 | ||
95 | <para>In contrast to | |
96 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command> | |
97 | may be used to boot full Linux-based operating systems in a | |
98 | container.</para> | |
99 | ||
100 | <para>Use a tool like | |
101 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
102 | <citerefentry project='die-net'><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
103 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
104 | or | |
105 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
106 | to set up an OS directory tree suitable as file system hierarchy | |
107 | for <command>systemd-nspawn</command> containers.</para> | |
108 | ||
109 | <para>Note that <command>systemd-nspawn</command> will mount file | |
110 | systems private to the container to <filename>/dev</filename>, | |
111 | <filename>/run</filename> and similar. These will not be visible | |
112 | outside of the container, and their contents will be lost when the | |
113 | container exits.</para> | |
114 | ||
115 | <para>Note that running two <command>systemd-nspawn</command> | |
116 | containers from the same directory tree will not make processes in | |
117 | them see each other. The PID namespace separation of the two | |
118 | containers is complete and the containers will share very few | |
119 | runtime objects except for the underlying file system. Use | |
120 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s | |
121 | <command>login</command> command to request an additional login | |
122 | prompt in a running container.</para> | |
123 | ||
124 | <para><command>systemd-nspawn</command> implements the | |
125 | <ulink | |
126 | url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container | |
127 | Interface</ulink> specification.</para> | |
128 | ||
129 | <para>As a safety check <command>systemd-nspawn</command> will | |
130 | verify the existence of <filename>/usr/lib/os-release</filename> | |
131 | or <filename>/etc/os-release</filename> in the container tree | |
132 | before starting the container (see | |
133 | <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). | |
134 | It might be necessary to add this file to the container tree | |
135 | manually if the OS of the container is too old to contain this | |
136 | file out-of-the-box.</para> | |
137 | </refsect1> | |
138 | ||
139 | <refsect1> | |
140 | <title>Options</title> | |
141 | ||
142 | <para>If option <option>-b</option> is specified, the arguments | |
143 | are used as arguments for the init binary. Otherwise, | |
144 | <replaceable>COMMAND</replaceable> specifies the program to launch | |
145 | in the container, and the remaining arguments are used as | |
146 | arguments for this program. If <option>-b</option> is not used and | |
147 | no arguments are specifed, a shell is launched in the | |
148 | container.</para> | |
149 | ||
150 | <para>The following options are understood:</para> | |
151 | ||
152 | <variablelist> | |
153 | <varlistentry> | |
154 | <term><option>-D</option></term> | |
155 | <term><option>--directory=</option></term> | |
156 | ||
157 | <listitem><para>Directory to use as file system root for the | |
158 | container.</para> | |
159 | ||
160 | <para>If neither <option>--directory=</option>, nor | |
161 | <option>--image=</option> is specified the directory is | |
162 | determined as <filename>/var/lib/machines/</filename> suffixed | |
163 | by the machine name as specified with | |
164 | <option>--machine=</option>. If neither | |
165 | <option>--directory=</option>, <option>--image=</option>, nor | |
166 | <option>--machine=</option> are specified, the current | |
167 | directory will be used. May not be specified together with | |
168 | <option>--image=</option>.</para></listitem> | |
169 | </varlistentry> | |
170 | ||
171 | <varlistentry> | |
172 | <term><option>--template=</option></term> | |
173 | ||
174 | <listitem><para>Directory or <literal>btrfs</literal> | |
175 | subvolume to use as template for the container's root | |
176 | directory. If this is specified and the container's root | |
177 | directory (as configured by <option>--directory=</option>) | |
178 | does not yet exist it is created as <literal>btrfs</literal> | |
179 | subvolume and populated from this template tree. Ideally, the | |
180 | specified template path refers to the root of a | |
181 | <literal>btrfs</literal> subvolume, in which case a simple | |
182 | copy-on-write snapshot is taken, and populating the root | |
183 | directory is instant. If the specified template path does not | |
184 | refer to the root of a <literal>btrfs</literal> subvolume (or | |
185 | not even to a <literal>btrfs</literal> file system at all), | |
186 | the tree is copied, which can be substantially more | |
187 | time-consuming. Note that if this option is used the | |
188 | container's root directory (in contrast to the template | |
189 | directory!) must be located on a <literal>btrfs</literal> file | |
190 | system, so that the <literal>btrfs</literal> subvolume may be | |
191 | created. May not be specified together with | |
192 | <option>--image=</option> or | |
193 | <option>--ephemeral</option>.</para></listitem> | |
194 | </varlistentry> | |
195 | ||
196 | <varlistentry> | |
197 | <term><option>-x</option></term> | |
198 | <term><option>--ephemeral</option></term> | |
199 | ||
200 | <listitem><para>If specified, the container is run with a | |
201 | temporary <literal>btrfs</literal> snapshot of its root | |
202 | directory (as configured with <option>--directory=</option>), | |
203 | that is removed immediately when the container terminates. | |
204 | This option is only supported if the root file system is | |
205 | <literal>btrfs</literal>. May not be specified together with | |
206 | <option>--image=</option> or | |
207 | <option>--template=</option>.</para></listitem> | |
208 | </varlistentry> | |
209 | ||
210 | <varlistentry> | |
211 | <term><option>-i</option></term> | |
212 | <term><option>--image=</option></term> | |
213 | ||
214 | <listitem><para>Disk image to mount the root directory for the | |
215 | container from. Takes a path to a regular file or to a block | |
216 | device node. The file or block device must contain | |
217 | either:</para> | |
218 | ||
219 | <itemizedlist> | |
220 | <listitem><para>An MBR partition table with a single | |
221 | partition of type 0x83 that is marked | |
222 | bootable.</para></listitem> | |
223 | ||
224 | <listitem><para>A GUID partition table (GPT) with a single | |
225 | partition of type | |
226 | 0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem> | |
227 | ||
228 | <listitem><para>A GUID partition table (GPT) with a marked | |
229 | root partition which is mounted as the root directory of the | |
230 | container. Optionally, GPT images may contain a home and/or | |
231 | a server data partition which are mounted to the appropriate | |
232 | places in the container. All these partitions must be | |
233 | identified by the partition types defined by the <ulink | |
234 | url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable | |
235 | Partitions Specification</ulink>.</para></listitem> | |
236 | </itemizedlist> | |
237 | ||
238 | <para>Any other partitions, such as foreign partitions, swap | |
239 | partitions or EFI system partitions are not mounted. May not | |
240 | be specified together with <option>--directory=</option>, | |
241 | <option>--template=</option> or | |
242 | <option>--ephemeral</option>.</para></listitem> | |
243 | </varlistentry> | |
244 | ||
245 | <varlistentry> | |
246 | <term><option>-b</option></term> | |
247 | <term><option>--boot</option></term> | |
248 | ||
249 | <listitem><para>Automatically search for an init binary and | |
250 | invoke it instead of a shell or a user supplied program. If | |
251 | this option is used, arguments specified on the command line | |
252 | are used as arguments for the init binary. This option may not | |
253 | be combined with <option>--share-system</option>. | |
254 | </para></listitem> | |
255 | </varlistentry> | |
256 | ||
257 | <varlistentry> | |
258 | <term><option>-u</option></term> | |
259 | <term><option>--user=</option></term> | |
260 | ||
261 | <listitem><para>After transitioning into the container, change | |
262 | to the specified user-defined in the container's user | |
263 | database. Like all other systemd-nspawn features, this is not | |
264 | a security feature and provides protection against accidental | |
265 | destructive operations only.</para></listitem> | |
266 | </varlistentry> | |
267 | ||
268 | <varlistentry> | |
269 | <term><option>-M</option></term> | |
270 | <term><option>--machine=</option></term> | |
271 | ||
272 | <listitem><para>Sets the machine name for this container. This | |
273 | name may be used to identify this container during its runtime | |
274 | (for example in tools like | |
275 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
276 | and similar), and is used to initialize the container's | |
277 | hostname (which the container can choose to override, | |
278 | however). If not specified, the last component of the root | |
279 | directory path of the container is used, possibly suffixed | |
280 | with a random identifier in case <option>--ephemeral</option> | |
281 | mode is selected. If the root directory selected is the host's | |
282 | root directory the host's hostname is used as default | |
283 | instead.</para></listitem> | |
284 | </varlistentry> | |
285 | ||
286 | <varlistentry> | |
287 | <term><option>--uuid=</option></term> | |
288 | ||
289 | <listitem><para>Set the specified UUID for the container. The | |
290 | init system will initialize | |
291 | <filename>/etc/machine-id</filename> from this if this file is | |
292 | not set yet. </para></listitem> | |
293 | </varlistentry> | |
294 | ||
295 | <varlistentry> | |
296 | <term><option>--slice=</option></term> | |
297 | ||
298 | <listitem><para>Make the container part of the specified | |
299 | slice, instead of the default | |
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300 | <filename>machine.slice</filename>. This is only applies if |
301 | the machine is run in its own scope unit, i.e. if | |
302 | <option>--keep-unit</option> is not used.</para> | |
303 | </listitem> | |
304 | </varlistentry> | |
305 | ||
306 | <varlistentry> | |
307 | <term><option>--property=</option></term> | |
308 | ||
309 | <listitem><para>Set a unit property on the scope unit to | |
310 | register for the machine. This only applies if the machine is | |
311 | run in its own scope unit, i.e. if | |
312 | <option>--keep-unit</option> is not used. Takes unit property | |
313 | assignments in the same format as <command>systemctl | |
314 | set-property</command>. This is useful to set memory limits | |
315 | and similar for machines.</para> | |
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316 | </listitem> |
317 | </varlistentry> | |
318 | ||
319 | <varlistentry> | |
320 | <term><option>--private-network</option></term> | |
321 | ||
322 | <listitem><para>Disconnect networking of the container from | |
323 | the host. This makes all network interfaces unavailable in the | |
324 | container, with the exception of the loopback device and those | |
325 | specified with <option>--network-interface=</option> and | |
326 | configured with <option>--network-veth</option>. If this | |
327 | option is specified, the CAP_NET_ADMIN capability will be | |
328 | added to the set of capabilities the container retains. The | |
329 | latter may be disabled by using | |
330 | <option>--drop-capability=</option>.</para></listitem> | |
331 | </varlistentry> | |
332 | ||
333 | <varlistentry> | |
334 | <term><option>--network-interface=</option></term> | |
335 | ||
336 | <listitem><para>Assign the specified network interface to the | |
337 | container. This will remove the specified interface from the | |
338 | calling namespace and place it in the container. When the | |
339 | container terminates, it is moved back to the host namespace. | |
340 | Note that <option>--network-interface=</option> implies | |
341 | <option>--private-network</option>. This option may be used | |
342 | more than once to add multiple network interfaces to the | |
343 | container.</para></listitem> | |
344 | </varlistentry> | |
345 | ||
346 | <varlistentry> | |
347 | <term><option>--network-macvlan=</option></term> | |
348 | ||
349 | <listitem><para>Create a <literal>macvlan</literal> interface | |
350 | of the specified Ethernet network interface and add it to the | |
351 | container. A <literal>macvlan</literal> interface is a virtual | |
352 | interface that adds a second MAC address to an existing | |
353 | physical Ethernet link. The interface in the container will be | |
354 | named after the interface on the host, prefixed with | |
355 | <literal>mv-</literal>. Note that | |
356 | <option>--network-macvlan=</option> implies | |
357 | <option>--private-network</option>. This option may be used | |
358 | more than once to add multiple network interfaces to the | |
359 | container.</para></listitem> | |
360 | </varlistentry> | |
361 | ||
362 | <varlistentry> | |
363 | <term><option>--network-ipvlan=</option></term> | |
364 | ||
365 | <listitem><para>Create an <literal>ipvlan</literal> interface | |
366 | of the specified Ethernet network interface and add it to the | |
367 | container. An <literal>ipvlan</literal> interface is a virtual | |
368 | interface, similar to a <literal>macvlan</literal> interface, | |
369 | which uses the same MAC address as the underlying interface. | |
370 | The interface in the container will be named after the | |
371 | interface on the host, prefixed with <literal>iv-</literal>. | |
372 | Note that <option>--network-ipvlan=</option> implies | |
373 | <option>--private-network</option>. This option may be used | |
374 | more than once to add multiple network interfaces to the | |
375 | container.</para></listitem> | |
376 | </varlistentry> | |
377 | ||
378 | <varlistentry> | |
379 | <term><option>-n</option></term> | |
380 | <term><option>--network-veth</option></term> | |
381 | ||
382 | <listitem><para>Create a virtual Ethernet link | |
383 | (<literal>veth</literal>) between host and container. The host | |
384 | side of the Ethernet link will be available as a network | |
385 | interface named after the container's name (as specified with | |
386 | <option>--machine=</option>), prefixed with | |
387 | <literal>ve-</literal>. The container side of the Ethernet | |
388 | link will be named <literal>host0</literal>. Note that | |
389 | <option>--network-veth</option> implies | |
390 | <option>--private-network</option>.</para></listitem> | |
391 | </varlistentry> | |
392 | ||
393 | <varlistentry> | |
394 | <term><option>--network-bridge=</option></term> | |
395 | ||
396 | <listitem><para>Adds the host side of the Ethernet link | |
397 | created with <option>--network-veth</option> to the specified | |
398 | bridge. Note that <option>--network-bridge=</option> implies | |
399 | <option>--network-veth</option>. If this option is used, the | |
400 | host side of the Ethernet link will use the | |
401 | <literal>vb-</literal> prefix instead of | |
402 | <literal>ve-</literal>.</para></listitem> | |
403 | </varlistentry> | |
404 | ||
405 | <varlistentry> | |
406 | <term><option>-p</option></term> | |
407 | <term><option>--port=</option></term> | |
408 | ||
409 | <listitem><para>If private networking is enabled, maps an IP | |
410 | port on the host onto an IP port on the container. Takes a | |
411 | protocol specifier (either <literal>tcp</literal> or | |
412 | <literal>udp</literal>), separated by a colon from a host port | |
413 | number in the range 1 to 65535, separated by a colon from a | |
414 | container port number in the range from 1 to 65535. The | |
415 | protocol specifier and its separating colon may be omitted, in | |
416 | which case <literal>tcp</literal> is assumed. The container | |
417 | port number and its colon may be ommitted, in which case the | |
418 | same port as the host port is implied. This option is only | |
419 | supported if private networking is used, such as | |
420 | <option>--network-veth</option> or | |
421 | <option>--network-bridge=</option>.</para></listitem> | |
422 | </varlistentry> | |
423 | ||
424 | <varlistentry> | |
425 | <term><option>-Z</option></term> | |
426 | <term><option>--selinux-context=</option></term> | |
427 | ||
428 | <listitem><para>Sets the SELinux security context to be used | |
429 | to label processes in the container.</para> | |
430 | </listitem> | |
431 | </varlistentry> | |
432 | ||
433 | <varlistentry> | |
434 | <term><option>-L</option></term> | |
435 | <term><option>--selinux-apifs-context=</option></term> | |
436 | ||
437 | <listitem><para>Sets the SELinux security context to be used | |
438 | to label files in the virtual API file systems in the | |
439 | container.</para> | |
440 | </listitem> | |
441 | </varlistentry> | |
442 | ||
443 | <varlistentry> | |
444 | <term><option>--capability=</option></term> | |
445 | ||
446 | <listitem><para>List one or more additional capabilities to | |
447 | grant the container. Takes a comma-separated list of | |
448 | capability names, see | |
449 | <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
450 | for more information. Note that the following capabilities | |
451 | will be granted in any way: CAP_CHOWN, CAP_DAC_OVERRIDE, | |
452 | CAP_DAC_READ_SEARCH, CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER, | |
453 | CAP_KILL, CAP_LEASE, CAP_LINUX_IMMUTABLE, | |
454 | CAP_NET_BIND_SERVICE, CAP_NET_BROADCAST, CAP_NET_RAW, | |
455 | CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, CAP_SETUID, | |
456 | CAP_SYS_ADMIN, CAP_SYS_CHROOT, CAP_SYS_NICE, CAP_SYS_PTRACE, | |
457 | CAP_SYS_TTY_CONFIG, CAP_SYS_RESOURCE, CAP_SYS_BOOT, | |
458 | CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN is | |
459 | retained if <option>--private-network</option> is specified. | |
460 | If the special value <literal>all</literal> is passed, all | |
461 | capabilities are retained.</para></listitem> | |
462 | </varlistentry> | |
463 | ||
464 | <varlistentry> | |
465 | <term><option>--drop-capability=</option></term> | |
466 | ||
467 | <listitem><para>Specify one or more additional capabilities to | |
468 | drop for the container. This allows running the container with | |
469 | fewer capabilities than the default (see | |
470 | above).</para></listitem> | |
471 | </varlistentry> | |
472 | ||
c6c8f6e2 LP |
473 | <varlistentry> |
474 | <term><option>--kill-signal=</option></term> | |
475 | ||
476 | <listitem><para>Specify the process signal to send to the | |
477 | container's PID 1 when nspawn itself receives SIGTERM, in | |
478 | order to trigger an orderly shutdown of the | |
479 | container. Defaults to SIGRTMIN+3 if <option>--boot</option> | |
480 | is used (on systemd-compatible init systems SIGRTMIN+3 | |
481 | triggers an orderly shutdown). Takes a signal name like | |
482 | <literal>SIGHUP</literal>, <literal>SIGTERM</literal> or | |
483 | similar as argument.</para></listitem> | |
484 | </varlistentry> | |
485 | ||
798d3a52 ZJS |
486 | <varlistentry> |
487 | <term><option>--link-journal=</option></term> | |
488 | ||
489 | <listitem><para>Control whether the container's journal shall | |
490 | be made visible to the host system. If enabled, allows viewing | |
491 | the container's journal files from the host (but not vice | |
492 | versa). Takes one of <literal>no</literal>, | |
493 | <literal>host</literal>, <literal>try-host</literal>, | |
494 | <literal>guest</literal>, <literal>try-guest</literal>, | |
495 | <literal>auto</literal>. If <literal>no</literal>, the journal | |
496 | is not linked. If <literal>host</literal>, the journal files | |
497 | are stored on the host file system (beneath | |
498 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
499 | and the subdirectory is bind-mounted into the container at the | |
500 | same location. If <literal>guest</literal>, the journal files | |
501 | are stored on the guest file system (beneath | |
502 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
503 | and the subdirectory is symlinked into the host at the same | |
504 | location. <literal>try-host</literal> and | |
505 | <literal>try-guest</literal> do the same but do not fail if | |
506 | the host does not have persistent journalling enabled. If | |
507 | <literal>auto</literal> (the default), and the right | |
508 | subdirectory of <filename>/var/log/journal</filename> exists, | |
509 | it will be bind mounted into the container. If the | |
510 | subdirectory does not exist, no linking is performed. | |
511 | Effectively, booting a container once with | |
512 | <literal>guest</literal> or <literal>host</literal> will link | |
513 | the journal persistently if further on the default of | |
514 | <literal>auto</literal> is used.</para></listitem> | |
515 | </varlistentry> | |
516 | ||
517 | <varlistentry> | |
518 | <term><option>-j</option></term> | |
519 | ||
520 | <listitem><para>Equivalent to | |
521 | <option>--link-journal=try-guest</option>.</para></listitem> | |
522 | </varlistentry> | |
523 | ||
524 | <varlistentry> | |
525 | <term><option>--read-only</option></term> | |
526 | ||
527 | <listitem><para>Mount the root file system read-only for the | |
528 | container.</para></listitem> | |
529 | </varlistentry> | |
530 | ||
531 | <varlistentry> | |
532 | <term><option>--bind=</option></term> | |
533 | <term><option>--bind-ro=</option></term> | |
534 | ||
535 | <listitem><para>Bind mount a file or directory from the host | |
536 | into the container. Either takes a path argument -- in which | |
537 | case the specified path will be mounted from the host to the | |
538 | same path in the container --, or a colon-separated pair of | |
539 | paths -- in which case the first specified path is the source | |
540 | in the host, and the second path is the destination in the | |
541 | container. The <option>--bind-ro=</option> option creates | |
542 | read-only bind mounts.</para></listitem> | |
543 | </varlistentry> | |
544 | ||
545 | <varlistentry> | |
546 | <term><option>--tmpfs=</option></term> | |
547 | ||
548 | <listitem><para>Mount a tmpfs file system into the container. | |
549 | Takes a single absolute path argument that specifies where to | |
550 | mount the tmpfs instance to (in which case the directory | |
551 | access mode will be chosen as 0755, owned by root/root), or | |
552 | optionally a colon-separated pair of path and mount option | |
553 | string, that is used for mounting (in which case the kernel | |
554 | default for access mode and owner will be chosen, unless | |
555 | otherwise specified). This option is particularly useful for | |
556 | mounting directories such as <filename>/var</filename> as | |
557 | tmpfs, to allow state-less systems, in particular when | |
558 | combined with <option>--read-only</option>.</para></listitem> | |
559 | </varlistentry> | |
560 | ||
561 | <varlistentry> | |
562 | <term><option>--setenv=</option></term> | |
563 | ||
564 | <listitem><para>Specifies an environment variable assignment | |
565 | to pass to the init process in the container, in the format | |
566 | <literal>NAME=VALUE</literal>. This may be used to override | |
567 | the default variables or to set additional variables. This | |
568 | parameter may be used more than once.</para></listitem> | |
569 | </varlistentry> | |
570 | ||
571 | <varlistentry> | |
572 | <term><option>--share-system</option></term> | |
573 | ||
574 | <listitem><para>Allows the container to share certain system | |
575 | facilities with the host. More specifically, this turns off | |
576 | PID namespacing, UTS namespacing and IPC namespacing, and thus | |
577 | allows the guest to see and interact more easily with | |
578 | processes outside of the container. Note that using this | |
579 | option makes it impossible to start up a full Operating System | |
580 | in the container, as an init system cannot operate in this | |
581 | mode. It is only useful to run specific programs or | |
582 | applications this way, without involving an init system in the | |
583 | container. This option implies <option>--register=no</option>. | |
584 | This option may not be combined with | |
585 | <option>--boot</option>.</para></listitem> | |
586 | </varlistentry> | |
587 | ||
588 | <varlistentry> | |
589 | <term><option>--register=</option></term> | |
590 | ||
591 | <listitem><para>Controls whether the container is registered | |
592 | with | |
593 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
594 | Takes a boolean argument, defaults to <literal>yes</literal>. | |
595 | This option should be enabled when the container runs a full | |
596 | Operating System (more specifically: an init system), and is | |
597 | useful to ensure that the container is accessible via | |
598 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
599 | and shown by tools such as | |
600 | <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. | |
601 | If the container does not run an init system, it is | |
602 | recommended to set this option to <literal>no</literal>. Note | |
603 | that <option>--share-system</option> implies | |
604 | <option>--register=no</option>. </para></listitem> | |
605 | </varlistentry> | |
606 | ||
607 | <varlistentry> | |
608 | <term><option>--keep-unit</option></term> | |
609 | ||
610 | <listitem><para>Instead of creating a transient scope unit to | |
611 | run the container in, simply register the service or scope | |
612 | unit <command>systemd-nspawn</command> has been invoked in | |
613 | with | |
614 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
615 | This has no effect if <option>--register=no</option> is used. | |
616 | This switch should be used if | |
617 | <command>systemd-nspawn</command> is invoked from within a | |
618 | service unit, and the service unit's sole purpose is to run a | |
619 | single <command>systemd-nspawn</command> container. This | |
620 | option is not available if run from a user | |
621 | session.</para></listitem> | |
622 | </varlistentry> | |
623 | ||
624 | <varlistentry> | |
625 | <term><option>--personality=</option></term> | |
626 | ||
627 | <listitem><para>Control the architecture ("personality") | |
628 | reported by | |
629 | <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
630 | in the container. Currently, only <literal>x86</literal> and | |
631 | <literal>x86-64</literal> are supported. This is useful when | |
632 | running a 32-bit container on a 64-bit host. If this setting | |
633 | is not used, the personality reported in the container is the | |
634 | same as the one reported on the host.</para></listitem> | |
635 | </varlistentry> | |
636 | ||
637 | <varlistentry> | |
638 | <term><option>-q</option></term> | |
639 | <term><option>--quiet</option></term> | |
640 | ||
641 | <listitem><para>Turns off any status output by the tool | |
642 | itself. When this switch is used, the only output from nspawn | |
643 | will be the console output of the container OS | |
644 | itself.</para></listitem> | |
645 | </varlistentry> | |
646 | ||
647 | <varlistentry> | |
648 | <term><option>--volatile</option><replaceable>=MODE</replaceable></term> | |
649 | ||
650 | <listitem><para>Boots the container in volatile mode. When no | |
651 | mode parameter is passed or when mode is specified as | |
652 | <literal>yes</literal> full volatile mode is enabled. This | |
653 | means the root directory is mounted as mostly unpopulated | |
654 | <literal>tmpfs</literal> instance, and | |
655 | <filename>/usr</filename> from the OS tree is mounted into it, | |
656 | read-only (the system thus starts up with read-only OS | |
657 | resources, but pristine state and configuration, any changes | |
658 | to the either are lost on shutdown). When the mode parameter | |
659 | is specified as <literal>state</literal> the OS tree is | |
660 | mounted read-only, but <filename>/var</filename> is mounted as | |
661 | <literal>tmpfs</literal> instance into it (the system thus | |
662 | starts up with read-only OS resources and configuration, but | |
663 | pristine state, any changes to the latter are lost on | |
664 | shutdown). When the mode parameter is specified as | |
665 | <literal>no</literal> (the default) the whole OS tree is made | |
666 | available writable.</para> | |
667 | ||
668 | <para>Note that setting this to <literal>yes</literal> or | |
669 | <literal>state</literal> will only work correctly with | |
670 | operating systems in the container that can boot up with only | |
671 | <filename>/usr</filename> mounted, and are able to populate | |
672 | <filename>/var</filename> automatically, as | |
673 | needed.</para></listitem> | |
674 | </varlistentry> | |
675 | ||
676 | <xi:include href="standard-options.xml" xpointer="help" /> | |
677 | <xi:include href="standard-options.xml" xpointer="version" /> | |
678 | </variablelist> | |
679 | ||
680 | </refsect1> | |
681 | ||
682 | <refsect1> | |
683 | <title>Examples</title> | |
684 | ||
685 | <example> | |
686 | <title>Download a Fedora image and start a shell in it</title> | |
687 | ||
688 | <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 |
689 | # systemd-nspawn -M Fedora-Cloud-Base-20141203-21</programlisting> |
690 | ||
798d3a52 ZJS |
691 | <para>This downloads an image using |
692 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
693 | and opens a shell in it.</para> | |
694 | </example> | |
e0ea94c1 | 695 | |
798d3a52 ZJS |
696 | <example> |
697 | <title>Build and boot a minimal Fedora distribution in a container</title> | |
8f7a3c14 | 698 | |
798d3a52 | 699 | <programlisting># dnf -y --releasever=21 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd dnf fedora-release vim-minimal |
2b3987a8 | 700 | # systemd-nspawn -bD /srv/mycontainer</programlisting> |
8f7a3c14 | 701 | |
798d3a52 ZJS |
702 | <para>This installs a minimal Fedora distribution into the |
703 | directory <filename noindex='true'>/srv/mycontainer/</filename> | |
704 | and then boots an OS in a namespace container in it.</para> | |
705 | </example> | |
8f7a3c14 | 706 | |
798d3a52 ZJS |
707 | <example> |
708 | <title>Spawn a shell in a container of a minimal Debian unstable distribution</title> | |
8f7a3c14 | 709 | |
798d3a52 | 710 | <programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/ |
25f5971b | 711 | # systemd-nspawn -D ~/debian-tree/</programlisting> |
8f7a3c14 | 712 | |
798d3a52 ZJS |
713 | <para>This installs a minimal Debian unstable distribution into |
714 | the directory <filename>~/debian-tree/</filename> and then | |
715 | spawns a shell in a namespace container in it.</para> | |
716 | </example> | |
8f7a3c14 | 717 | |
798d3a52 ZJS |
718 | <example> |
719 | <title>Boot a minimal Arch Linux distribution in a container</title> | |
68562936 | 720 | |
798d3a52 | 721 | <programlisting># pacstrap -c -d ~/arch-tree/ base |
68562936 WG |
722 | # systemd-nspawn -bD ~/arch-tree/</programlisting> |
723 | ||
798d3a52 ZJS |
724 | <para>This installs a mimimal Arch Linux distribution into the |
725 | directory <filename>~/arch-tree/</filename> and then boots an OS | |
726 | in a namespace container in it.</para> | |
727 | </example> | |
68562936 | 728 | |
798d3a52 ZJS |
729 | <example> |
730 | <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title> | |
f9f4dd51 | 731 | |
798d3a52 | 732 | <programlisting># systemd-nspawn -D / -xb</programlisting> |
f9f4dd51 | 733 | |
798d3a52 ZJS |
734 | <para>This runs a copy of the host system in a |
735 | <literal>btrfs</literal> snapshot which is removed immediately | |
736 | when the container exits. All file system changes made during | |
737 | runtime will be lost on shutdown, hence.</para> | |
738 | </example> | |
f9f4dd51 | 739 | |
798d3a52 ZJS |
740 | <example> |
741 | <title>Run a container with SELinux sandbox security contexts</title> | |
a8828ed9 | 742 | |
798d3a52 | 743 | <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container |
a8828ed9 | 744 | # 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 |
745 | </example> |
746 | </refsect1> | |
747 | ||
748 | <refsect1> | |
749 | <title>Exit status</title> | |
750 | ||
751 | <para>The exit code of the program executed in the container is | |
752 | returned.</para> | |
753 | </refsect1> | |
754 | ||
755 | <refsect1> | |
756 | <title>See Also</title> | |
757 | <para> | |
758 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
759 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
760 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
761 | <citerefentry project='die-net'><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
762 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
763 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
764 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
765 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
766 | <citerefentry><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
767 | </para> | |
768 | </refsect1> | |
8f7a3c14 LP |
769 | |
770 | </refentry> |