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diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml deleted file mode 100644 index c449edee89..0000000000 --- a/man/systemd-nspawn.xml +++ /dev/null @@ -1,1088 +0,0 @@ -<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<!-- - This file is part of systemd. - - Copyright 2010 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="systemd-nspawn" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>systemd-nspawn</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>systemd-nspawn</refentrytitle> - <manvolnum>1</manvolnum> - </refmeta> - - <refnamediv> - <refname>systemd-nspawn</refname> - <refpurpose>Spawn a namespace container for debugging, testing and building</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <cmdsynopsis> - <command>systemd-nspawn</command> - <arg choice="opt" rep="repeat">OPTIONS</arg> - <arg choice="opt"><replaceable>COMMAND</replaceable> - <arg choice="opt" rep="repeat">ARGS</arg> - </arg> - </cmdsynopsis> - <cmdsynopsis> - <command>systemd-nspawn</command> - <arg choice="plain">--boot</arg> - <arg choice="opt" rep="repeat">OPTIONS</arg> - <arg choice="opt" rep="repeat">ARGS</arg> - </cmdsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para><command>systemd-nspawn</command> may be used to run a command or OS in a light-weight namespace - container. In many ways it is similar to <citerefentry - project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, but more powerful - since it fully virtualizes the file system hierarchy, as well as the process tree, the various IPC subsystems and - the host and domain name.</para> - - <para><command>systemd-nspawn</command> may be invoked on any directory tree containing an operating system tree, - using the <option>--directory=</option> command line option. By using the <option>--machine=</option> option an OS - tree is automatically searched for in a couple of locations, most importantly in - <filename>/var/lib/machines</filename>, the suggested directory to place container images installed on the - system.</para> - - <para>In contrast to <citerefentry - project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command> - may be used to boot full Linux-based operating systems in a container.</para> - - <para><command>systemd-nspawn</command> limits access to various kernel interfaces in the container to read-only, - such as <filename>/sys</filename>, <filename>/proc/sys</filename> or <filename>/sys/fs/selinux</filename>. The - host's network interfaces and the system clock may not be changed from within the container. Device nodes may not - be created. The host system cannot be rebooted and kernel modules may not be loaded from within the - container.</para> - - <para>Use a tool like <citerefentry - project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry - project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or - <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> to - set up an OS directory tree suitable as file system hierarchy for <command>systemd-nspawn</command> containers. See - the Examples section below for details on suitable invocation of these commands.</para> - - <para>As a safety check <command>systemd-nspawn</command> will verify the existence of - <filename>/usr/lib/os-release</filename> or <filename>/etc/os-release</filename> in the container tree before - starting the container (see - <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). It might be - necessary to add this file to the container tree manually if the OS of the container is too old to contain this - file out-of-the-box.</para> - - <para><command>systemd-nspawn</command> may be invoked directly from the interactive command line or run as system - service in the background. In this mode each container instance runs as its own service instance; a default - template unit file <filename>systemd-nspawn@.service</filename> is provided to make this easy, taking the container - name as instance identifier. Note that different default options apply when <command>systemd-nspawn</command> is - invoked by the template unit file than interactively on the command line. Most importantly the template unit file - makes use of the <option>--boot</option> which is not the default in case <command>systemd-nspawn</command> is - invoked from the interactive command line. Further differences with the defaults are documented along with the - various supported options below.</para> - - <para>The <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> tool may - be used to execute a number of operations on containers. In particular it provides easy-to-use commands to run - containers as system services using the <filename>systemd-nspawn@.service</filename> template unit - file.</para> - - <para>Along with each container a settings file with the <filename>.nspawn</filename> suffix may exist, containing - additional settings to apply when running the container. See - <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry> for - details. Settings files override the default options used by the <filename>systemd-nspawn@.service</filename> - template unit file, making it usually unnecessary to alter this template file directly.</para> - - <para>Note that <command>systemd-nspawn</command> will mount file systems private to the container to - <filename>/dev</filename>, <filename>/run</filename> and similar. These will not be visible outside of the - container, and their contents will be lost when the container exits.</para> - - <para>Note that running two <command>systemd-nspawn</command> containers from the same directory tree will not make - processes in them see each other. The PID namespace separation of the two containers is complete and the containers - will share very few runtime objects except for the underlying file system. Use - <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s - <command>login</command> or <command>shell</command> commands to request an additional login session in a running - container.</para> - - <para><command>systemd-nspawn</command> implements the <ulink - url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container Interface</ulink> - specification.</para> - - <para>While running, containers invoked with <command>systemd-nspawn</command> are registered with the - <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> service that - keeps track of running containers, and provides programming interfaces to interact with them.</para> - </refsect1> - - <refsect1> - <title>Options</title> - - <para>If option <option>-b</option> is specified, the arguments - are used as arguments for the init binary. Otherwise, - <replaceable>COMMAND</replaceable> specifies the program to launch - in the container, and the remaining arguments are used as - arguments for this program. If <option>--boot</option> is not used and - no arguments are specified, a shell is launched in the - container.</para> - - <para>The following options are understood:</para> - - <variablelist> - <varlistentry> - <term><option>-D</option></term> - <term><option>--directory=</option></term> - - <listitem><para>Directory to use as file system root for the - container.</para> - - <para>If neither <option>--directory=</option>, nor - <option>--image=</option> is specified the directory is - determined by searching for a directory named the same as the - machine name specified with <option>--machine=</option>. See - <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> - section "Files and Directories" for the precise search path.</para> - - <para>If neither <option>--directory=</option>, - <option>--image=</option>, nor <option>--machine=</option> - are specified, the current directory will - be used. May not be specified together with - <option>--image=</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--template=</option></term> - - <listitem><para>Directory or <literal>btrfs</literal> - subvolume to use as template for the container's root - directory. If this is specified and the container's root - directory (as configured by <option>--directory=</option>) - does not yet exist it is created as <literal>btrfs</literal> - subvolume and populated from this template tree. Ideally, the - specified template path refers to the root of a - <literal>btrfs</literal> subvolume, in which case a simple - copy-on-write snapshot is taken, and populating the root - directory is instant. If the specified template path does not - refer to the root of a <literal>btrfs</literal> subvolume (or - not even to a <literal>btrfs</literal> file system at all), - the tree is copied, which can be substantially more - time-consuming. Note that if this option is used the - container's root directory (in contrast to the template - directory!) must be located on a <literal>btrfs</literal> file - system, so that the <literal>btrfs</literal> subvolume may be - created. May not be specified together with - <option>--image=</option> or - <option>--ephemeral</option>.</para> - - <para>Note that this switch leaves host name, machine ID and - all other settings that could identify the instance - unmodified.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-x</option></term> - <term><option>--ephemeral</option></term> - - <listitem><para>If specified, the container is run with a - temporary <literal>btrfs</literal> snapshot of its root - directory (as configured with <option>--directory=</option>), - that is removed immediately when the container terminates. - This option is only supported if the root file system is - <literal>btrfs</literal>. May not be specified together with - <option>--image=</option> or - <option>--template=</option>.</para> - <para>Note that this switch leaves host name, machine ID and - all other settings that could identify the instance - unmodified.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-i</option></term> - <term><option>--image=</option></term> - - <listitem><para>Disk image to mount the root directory for the - container from. Takes a path to a regular file or to a block - device node. The file or block device must contain - either:</para> - - <itemizedlist> - <listitem><para>An MBR partition table with a single - partition of type 0x83 that is marked - bootable.</para></listitem> - - <listitem><para>A GUID partition table (GPT) with a single - partition of type - 0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem> - - <listitem><para>A GUID partition table (GPT) with a marked - root partition which is mounted as the root directory of the - container. Optionally, GPT images may contain a home and/or - a server data partition which are mounted to the appropriate - places in the container. All these partitions must be - identified by the partition types defined by the <ulink - url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable - Partitions Specification</ulink>.</para></listitem> - </itemizedlist> - - <para>Any other partitions, such as foreign partitions, swap - partitions or EFI system partitions are not mounted. May not - be specified together with <option>--directory=</option>, - <option>--template=</option> or - <option>--ephemeral</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-a</option></term> - <term><option>--as-pid2</option></term> - - <listitem><para>Invoke the shell or specified program as process ID (PID) 2 instead of PID 1 (init). By - default, if neither this option nor <option>--boot</option> is used, the selected binary is run as process with - PID 1, a mode only suitable for programs that are aware of the special semantics that the process with PID 1 - has on UNIX. For example, it needs to reap all processes reparented to it, and should implement - <command>sysvinit</command> compatible signal handling (specifically: it needs to reboot on SIGINT, reexecute - on SIGTERM, reload configuration on SIGHUP, and so on). With <option>--as-pid2</option> a minimal stub init - process is run as PID 1 and the selected binary is executed as PID 2 (and hence does not need to implement any - special semantics). The stub init process will reap processes as necessary and react appropriately to - signals. It is recommended to use this mode to invoke arbitrary commands in containers, unless they have been - modified to run correctly as PID 1. Or in other words: this switch should be used for pretty much all commands, - except when the command refers to an init or shell implementation, as these are generally capable of running - correctly as PID 1. This option may not be combined with <option>--boot</option>.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-b</option></term> - <term><option>--boot</option></term> - - <listitem><para>Automatically search for an init binary and invoke it as PID 1, instead of a shell or a user - supplied program. If this option is used, arguments specified on the command line are used as arguments for the - init binary. This option may not be combined with <option>--as-pid2</option>.</para> - - <para>The following table explains the different modes of invocation and relationship to - <option>--as-pid2</option> (see above):</para> - - <table> - <title>Invocation Mode</title> - <tgroup cols='2' align='left' colsep='1' rowsep='1'> - <colspec colname="switch" /> - <colspec colname="explanation" /> - <thead> - <row> - <entry>Switch</entry> - <entry>Explanation</entry> - </row> - </thead> - <tbody> - <row> - <entry>Neither <option>--as-pid2</option> nor <option>--boot</option> specified</entry> - <entry>The passed parameters are interpreted as the command line, which is executed as PID 1 in the container.</entry> - </row> - - <row> - <entry><option>--as-pid2</option> specified</entry> - <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> - </row> - - <row> - <entry><option>--boot</option> specified</entry> - <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> - </row> - - </tbody> - </tgroup> - </table> - - <para>Note that <option>--boot</option> is the default mode of operation if the - <filename>systemd-nspawn@.service</filename> template unit file is used.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--chdir=</option></term> - - <listitem><para>Change to the specified working directory before invoking the process in the container. Expects - an absolute path in the container's file system namespace.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-u</option></term> - <term><option>--user=</option></term> - - <listitem><para>After transitioning into the container, change - to the specified user-defined in the container's user - database. Like all other systemd-nspawn features, this is not - a security feature and provides protection against accidental - destructive operations only.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-M</option></term> - <term><option>--machine=</option></term> - - <listitem><para>Sets the machine name for this container. This - name may be used to identify this container during its runtime - (for example in tools like - <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> - and similar), and is used to initialize the container's - hostname (which the container can choose to override, - however). If not specified, the last component of the root - directory path of the container is used, possibly suffixed - with a random identifier in case <option>--ephemeral</option> - mode is selected. If the root directory selected is the host's - root directory the host's hostname is used as default - instead.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--uuid=</option></term> - - <listitem><para>Set the specified UUID for the container. The - init system will initialize - <filename>/etc/machine-id</filename> from this if this file is - not set yet. Note that this option takes effect only if - <filename>/etc/machine-id</filename> in the container is - unpopulated.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--slice=</option></term> - - <listitem><para>Make the container part of the specified - slice, instead of the default - <filename>machine.slice</filename>. This is only applies if - the machine is run in its own scope unit, i.e. if - <option>--keep-unit</option> is not used.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--property=</option></term> - - <listitem><para>Set a unit property on the scope unit to - register for the machine. This only applies if the machine is - run in its own scope unit, i.e. if - <option>--keep-unit</option> is not used. Takes unit property - assignments in the same format as <command>systemctl - set-property</command>. This is useful to set memory limits - and similar for machines.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--private-users=</option></term> - - <listitem><para>Controls user namespacing. If enabled, the container will run with its own private set of UNIX - user and group ids (UIDs and GIDs). This involves mapping the private UIDs/GIDs used in the container (starting - with the container's root user 0 and up) to a range of UIDs/GIDs on the host that are not used for other - purposes (usually in the range beyond the host's UID/GID 65536). The parameter may be specified as follows:</para> - - <orderedlist> - <listitem><para>If one or two colon-separated numbers are specified, user namespacing is turned on. The first - parameter specifies the first host UID/GID to assign to the container, the second parameter specifies the - number of host UIDs/GIDs to assign to the container. If the second parameter is omitted, 65536 UIDs/GIDs are - assigned.</para></listitem> - - <listitem><para>If the parameter is omitted, or true, user namespacing is turned on. The UID/GID range to - use is determined automatically from the file ownership of the root directory of the container's directory - tree. To use this option, make sure to prepare the directory tree in advance, and ensure that all files and - directories in it are owned by UIDs/GIDs in the range you'd like to use. Also, make sure that used file ACLs - exclusively reference UIDs/GIDs in the appropriate range. If this mode is used the number of UIDs/GIDs - assigned to the container for use is 65536, and the UID/GID of the root directory must be a multiple of - 65536.</para></listitem> - - <listitem><para>If the parameter is false, user namespacing is turned off. This is the default.</para> - </listitem> - - <listitem><para>The special value <literal>pick</literal> turns on user namespacing. In this case the UID/GID - range is automatically chosen. As first step, the file owner of the root directory of the container's - directory tree is read, and it is checked that it is currently not used by the system otherwise (in - particular, that no other container is using it). If this check is successful, the UID/GID range determined - this way is used, similar to the behavior if "yes" is specified. If the check is not successful (and thus - the UID/GID range indicated in the root directory's file owner is already used elsewhere) a new – currently - unused – UID/GID range of 65536 UIDs/GIDs is randomly chosen between the host UID/GIDs of 524288 and - 1878982656, always starting at a multiple of 65536. This setting implies - <option>--private-users-chown</option> (see below), which has the effect that the files and directories in - the container's directory tree will be owned by the appropriate users of the range picked. Using this option - makes user namespace behavior fully automatic. Note that the first invocation of a previously unused - container image might result in picking a new UID/GID range for it, and thus in the (possibly expensive) file - ownership adjustment operation. However, subsequent invocations of the container will be cheap (unless of - course the picked UID/GID range is assigned to a different use by then).</para></listitem> - </orderedlist> - - <para>It is recommended to assign at least 65536 UIDs/GIDs to each container, so that the usable UID/GID range in the - container covers 16 bit. For best security, do not assign overlapping UID/GID ranges to multiple containers. It is - hence a good idea to use the upper 16 bit of the host 32-bit UIDs/GIDs as container identifier, while the lower 16 - bit encode the container UID/GID used. This is in fact the behavior enforced by the - <option>--private-users=pick</option> option.</para> - - <para>When user namespaces are used, the GID range assigned to each container is always chosen identical to the - UID range.</para> - - <para>In most cases, using <option>--private-users=pick</option> is the recommended option as it enhances - container security massively and operates fully automatically in most cases.</para> - - <para>Note that the picked UID/GID range is not written to <filename>/etc/passwd</filename> or - <filename>/etc/group</filename>. In fact, the allocation of the range is not stored persistently anywhere, - except in the file ownership of the files and directories of the container.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--private-users-chown</option></term> - - <listitem><para>If specified, all files and directories in the container's directory tree will adjusted so that - they are owned to the appropriate UIDs/GIDs selected for the container (see above). This operation is - potentially expensive, as it involves descending and iterating through the full directory tree of the - container. Besides actual file ownership, file ACLs are adjusted as well.</para> - - <para>This option is implied if <option>--private-users=pick</option> is used. This option has no effect if - user namespacing is not used.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-U</option></term> - - <listitem><para>If the kernel supports the user namespaces feature, equivalent to - <option>--private-users=pick --private-users-chown</option>, otherwise equivalent to - <option>--private-users=no</option>.</para> - - <para>Note that <option>-U</option> is the default if the - <filename>systemd-nspawn@.service</filename> template unit file is used.</para> - - <para>Note: it is possible to undo the effect of <option>--private-users-chown</option> (or - <option>-U</option>) on the file system by redoing the operation with the first UID of 0:</para> - - <programlisting>systemd-nspawn … --private-users=0 --private-users-chown</programlisting> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--private-network</option></term> - - <listitem><para>Disconnect networking of the container from - the host. This makes all network interfaces unavailable in the - container, with the exception of the loopback device and those - specified with <option>--network-interface=</option> and - configured with <option>--network-veth</option>. If this - option is specified, the CAP_NET_ADMIN capability will be - added to the set of capabilities the container retains. The - latter may be disabled by using - <option>--drop-capability=</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-interface=</option></term> - - <listitem><para>Assign the specified network interface to the - container. This will remove the specified interface from the - calling namespace and place it in the container. When the - container terminates, it is moved back to the host namespace. - Note that <option>--network-interface=</option> implies - <option>--private-network</option>. This option may be used - more than once to add multiple network interfaces to the - container.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-macvlan=</option></term> - - <listitem><para>Create a <literal>macvlan</literal> interface - of the specified Ethernet network interface and add it to the - container. A <literal>macvlan</literal> interface is a virtual - interface that adds a second MAC address to an existing - physical Ethernet link. The interface in the container will be - named after the interface on the host, prefixed with - <literal>mv-</literal>. Note that - <option>--network-macvlan=</option> implies - <option>--private-network</option>. This option may be used - more than once to add multiple network interfaces to the - container.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-ipvlan=</option></term> - - <listitem><para>Create an <literal>ipvlan</literal> interface - of the specified Ethernet network interface and add it to the - container. An <literal>ipvlan</literal> interface is a virtual - interface, similar to a <literal>macvlan</literal> interface, - which uses the same MAC address as the underlying interface. - The interface in the container will be named after the - interface on the host, prefixed with <literal>iv-</literal>. - Note that <option>--network-ipvlan=</option> implies - <option>--private-network</option>. This option may be used - more than once to add multiple network interfaces to the - container.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-n</option></term> - <term><option>--network-veth</option></term> - - <listitem><para>Create a virtual Ethernet link (<literal>veth</literal>) between host and container. The host - side of the Ethernet link will be available as a network interface named after the container's name (as - specified with <option>--machine=</option>), prefixed with <literal>ve-</literal>. The container side of the - Ethernet link will be named <literal>host0</literal>. The <option>--network-veth</option> option implies - <option>--private-network</option>.</para> - - <para>Note that - <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> - includes by default a network file <filename>/usr/lib/systemd/network/80-container-ve.network</filename> - matching the host-side interfaces created this way, which contains settings to enable automatic address - provisioning on the created virtual link via DHCP, as well as automatic IP routing onto the host's external - network interfaces. It also contains <filename>/usr/lib/systemd/network/80-container-host0.network</filename> - matching the container-side interface created this way, containing settings to enable client side address - assignment via DHCP. In case <filename>systemd-networkd</filename> is running on both the host and inside the - container, automatic IP communication from the container to the host is thus available, with further - connectivity to the external network.</para> - - <para>Note that <option>--network-veth</option> is the default if the - <filename>systemd-nspawn@.service</filename> template unit file is used.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-veth-extra=</option></term> - - <listitem><para>Adds an additional virtual Ethernet link - between host and container. Takes a colon-separated pair of - host interface name and container interface name. The latter - may be omitted in which case the container and host sides will - be assigned the same name. This switch is independent of - <option>--network-veth</option>, and — in contrast — may be - used multiple times, and allows configuration of the network - interface names. Note that <option>--network-bridge=</option> - has no effect on interfaces created with - <option>--network-veth-extra=</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-bridge=</option></term> - - <listitem><para>Adds the host side of the Ethernet link created with <option>--network-veth</option> to the - specified Ethernet bridge interface. Expects a valid network interface name of a bridge device as - argument. Note that <option>--network-bridge=</option> implies <option>--network-veth</option>. If this option - is used, the host side of the Ethernet link will use the <literal>vb-</literal> prefix instead of - <literal>ve-</literal>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--network-zone=</option></term> - - <listitem><para>Creates a virtual Ethernet link (<literal>veth</literal>) to the container and adds it to an - automatically managed Ethernet bridge interface. The bridge interface is named after the passed argument, - prefixed with <literal>vz-</literal>. The bridge interface is automatically created when the first container - configured for its name is started, and is automatically removed when the last container configured for its - name exits. Hence, each bridge interface configured this way exists only as long as there's at least one - container referencing it running. This option is very similar to <option>--network-bridge=</option>, besides - this automatic creation/removal of the bridge device.</para> - - <para>This setting makes it easy to place multiple related containers on a common, virtual Ethernet-based - broadcast domain, here called a "zone". Each container may only be part of one zone, but each zone may contain - any number of containers. Each zone is referenced by its name. Names may be chosen freely (as long as they form - valid network interface names when prefixed with <literal>vz-</literal>), and it is sufficient to pass the same - name to the <option>--network-zones=</option> switch of the various concurrently running containers to join - them in one zone.</para> - - <para>Note that - <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> - includes by default a network file <filename>/usr/lib/systemd/network/80-container-vz.network</filename> - matching the bridge interfaces created this way, which contains settings to enable automatic address - provisioning on the created virtual network via DHCP, as well as automatic IP routing onto the host's external - network interfaces. Using <option>--network-zone=</option> is hence in most cases fully automatic and - sufficient to connect multiple local containers in a joined broadcast domain to the host, with further - connectivity to the external network.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-p</option></term> - <term><option>--port=</option></term> - - <listitem><para>If private networking is enabled, maps an IP - port on the host onto an IP port on the container. Takes a - protocol specifier (either <literal>tcp</literal> or - <literal>udp</literal>), separated by a colon from a host port - number in the range 1 to 65535, separated by a colon from a - container port number in the range from 1 to 65535. The - protocol specifier and its separating colon may be omitted, in - which case <literal>tcp</literal> is assumed. The container - port number and its colon may be omitted, in which case the - same port as the host port is implied. This option is only - supported if private networking is used, such as with - <option>--network-veth</option>, <option>--network-zone=</option> - <option>--network-bridge=</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-Z</option></term> - <term><option>--selinux-context=</option></term> - - <listitem><para>Sets the SELinux security context to be used - to label processes in the container.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-L</option></term> - <term><option>--selinux-apifs-context=</option></term> - - <listitem><para>Sets the SELinux security context to be used - to label files in the virtual API file systems in the - container.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>--capability=</option></term> - - <listitem><para>List one or more additional capabilities to - grant the container. Takes a comma-separated list of - capability names, see - <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> - for more information. Note that the following capabilities - will be granted in any way: CAP_CHOWN, CAP_DAC_OVERRIDE, - CAP_DAC_READ_SEARCH, CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER, - CAP_KILL, CAP_LEASE, CAP_LINUX_IMMUTABLE, - CAP_NET_BIND_SERVICE, CAP_NET_BROADCAST, CAP_NET_RAW, - CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, CAP_SETUID, - CAP_SYS_ADMIN, CAP_SYS_CHROOT, CAP_SYS_NICE, CAP_SYS_PTRACE, - CAP_SYS_TTY_CONFIG, CAP_SYS_RESOURCE, CAP_SYS_BOOT, - CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN is - retained if <option>--private-network</option> is specified. - If the special value <literal>all</literal> is passed, all - capabilities are retained.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--drop-capability=</option></term> - - <listitem><para>Specify one or more additional capabilities to - drop for the container. This allows running the container with - fewer capabilities than the default (see - above).</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--kill-signal=</option></term> - - <listitem><para>Specify the process signal to send to the - container's PID 1 when nspawn itself receives SIGTERM, in - order to trigger an orderly shutdown of the - container. Defaults to SIGRTMIN+3 if <option>--boot</option> - is used (on systemd-compatible init systems SIGRTMIN+3 - triggers an orderly shutdown). For a list of valid signals, see - <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--link-journal=</option></term> - - <listitem><para>Control whether the container's journal shall - be made visible to the host system. If enabled, allows viewing - the container's journal files from the host (but not vice - versa). Takes one of <literal>no</literal>, - <literal>host</literal>, <literal>try-host</literal>, - <literal>guest</literal>, <literal>try-guest</literal>, - <literal>auto</literal>. If <literal>no</literal>, the journal - is not linked. If <literal>host</literal>, the journal files - are stored on the host file system (beneath - <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) - and the subdirectory is bind-mounted into the container at the - same location. If <literal>guest</literal>, the journal files - are stored on the guest file system (beneath - <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) - and the subdirectory is symlinked into the host at the same - location. <literal>try-host</literal> and - <literal>try-guest</literal> do the same but do not fail if - the host does not have persistent journaling enabled. If - <literal>auto</literal> (the default), and the right - subdirectory of <filename>/var/log/journal</filename> exists, - it will be bind mounted into the container. If the - subdirectory does not exist, no linking is performed. - Effectively, booting a container once with - <literal>guest</literal> or <literal>host</literal> will link - the journal persistently if further on the default of - <literal>auto</literal> is used.</para> - - <para>Note that <option>--link-journal=try-guest</option> is the default if the - <filename>systemd-nspawn@.service</filename> template unit file is used.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-j</option></term> - - <listitem><para>Equivalent to - <option>--link-journal=try-guest</option>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--read-only</option></term> - - <listitem><para>Mount the root file system read-only for the - container.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--bind=</option></term> - <term><option>--bind-ro=</option></term> - - <listitem><para>Bind mount a file or directory from the host - into the container. Takes one of: a path argument — in which - case the specified path will be mounted from the host to the - same path in the container —, or a colon-separated pair of - paths — in which case the first specified path is the source - in the host, and the second path is the destination in the - container —, or a colon-separated triple of source path, - destination path and mount options. Mount options are - comma-separated and currently, only "rbind" and "norbind" - are allowed. Defaults to "rbind". Backslash escapes are interpreted, so - <literal>\:</literal> may be used to embed colons in either path. - This option may be specified multiple times for - creating multiple independent bind mount points. The - <option>--bind-ro=</option> option creates read-only bind - mounts.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--tmpfs=</option></term> - - <listitem><para>Mount a tmpfs file system into the container. - Takes a single absolute path argument that specifies where to - mount the tmpfs instance to (in which case the directory - access mode will be chosen as 0755, owned by root/root), or - optionally a colon-separated pair of path and mount option - string that is used for mounting (in which case the kernel - default for access mode and owner will be chosen, unless - otherwise specified). This option is particularly useful for - mounting directories such as <filename>/var</filename> as - tmpfs, to allow state-less systems, in particular when - combined with <option>--read-only</option>. - Backslash escapes are interpreted in the path, so - <literal>\:</literal> may be used to embed colons in the path. - </para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--overlay=</option></term> - <term><option>--overlay-ro=</option></term> - - <listitem><para>Combine multiple directory trees into one - overlay file system and mount it into the container. Takes a - list of colon-separated paths to the directory trees to - combine and the destination mount point.</para> - - <para>Backslash escapes are interpreted in the paths, so - <literal>\:</literal> may be used to embed colons in the paths. - </para> - - <para>If three or more paths are specified, then the last - specified path is the destination mount point in the - container, all paths specified before refer to directory trees - on the host and are combined in the specified order into one - overlay file system. The left-most path is hence the lowest - directory tree, the second-to-last path the highest directory - tree in the stacking order. If <option>--overlay-ro=</option> - is used instead of <option>--overlay=</option>, a read-only - overlay file system is created. If a writable overlay file - system is created, all changes made to it are written to the - highest directory tree in the stacking order, i.e. the - second-to-last specified.</para> - - <para>If only two paths are specified, then the second - specified path is used both as the top-level directory tree in - the stacking order as seen from the host, as well as the mount - point for the overlay file system in the container. At least - two paths have to be specified.</para> - - <para>For details about overlay file systems, see <ulink - url="https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt">overlayfs.txt</ulink>. Note - that the semantics of overlay file systems are substantially - different from normal file systems, in particular regarding - reported device and inode information. Device and inode - information may change for a file while it is being written - to, and processes might see out-of-date versions of files at - times. Note that this switch automatically derives the - <literal>workdir=</literal> mount option for the overlay file - system from the top-level directory tree, making it a sibling - of it. It is hence essential that the top-level directory tree - is not a mount point itself (since the working directory must - be on the same file system as the top-most directory - tree). Also note that the <literal>lowerdir=</literal> mount - option receives the paths to stack in the opposite order of - this switch.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-E <replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term> - <term><option>--setenv=<replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term> - - <listitem><para>Specifies an environment variable assignment - to pass to the init process in the container, in the format - <literal>NAME=VALUE</literal>. This may be used to override - the default variables or to set additional variables. This - parameter may be used more than once.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--register=</option></term> - - <listitem><para>Controls whether the container is registered - with - <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. - Takes a boolean argument, which defaults to <literal>yes</literal>. - This option should be enabled when the container runs a full - Operating System (more specifically: an init system), and is - useful to ensure that the container is accessible via - <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> - and shown by tools such as - <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. - If the container does not run an init system, it is - recommended to set this option to <literal>no</literal>.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--keep-unit</option></term> - - <listitem><para>Instead of creating a transient scope unit to - run the container in, simply register the service or scope - unit <command>systemd-nspawn</command> has been invoked in - with - <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. - This has no effect if <option>--register=no</option> is used. - This switch should be used if - <command>systemd-nspawn</command> is invoked from within a - service unit, and the service unit's sole purpose is to run a - single <command>systemd-nspawn</command> container. This - option is not available if run from a user - session.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--personality=</option></term> - - <listitem><para>Control the architecture ("personality") - reported by - <citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> - in the container. Currently, only <literal>x86</literal> and - <literal>x86-64</literal> are supported. This is useful when - running a 32-bit container on a 64-bit host. If this setting - is not used, the personality reported in the container is the - same as the one reported on the host.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>-q</option></term> - <term><option>--quiet</option></term> - - <listitem><para>Turns off any status output by the tool - itself. When this switch is used, the only output from nspawn - will be the console output of the container OS - itself.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--volatile</option></term> - <term><option>--volatile=</option><replaceable>MODE</replaceable></term> - - <listitem><para>Boots the container in volatile mode. When no - mode parameter is passed or when mode is specified as - <option>yes</option>, full volatile mode is enabled. This - means the root directory is mounted as a mostly unpopulated - <literal>tmpfs</literal> instance, and - <filename>/usr</filename> from the OS tree is mounted into it - in read-only mode (the system thus starts up with read-only OS - image, but pristine state and configuration, any changes - are lost on shutdown). When the mode parameter - is specified as <option>state</option>, the OS tree is - mounted read-only, but <filename>/var</filename> is mounted as - a <literal>tmpfs</literal> instance into it (the system thus - starts up with read-only OS resources and configuration, but - pristine state, and any changes to the latter are lost on - shutdown). When the mode parameter is specified as - <option>no</option> (the default), the whole OS tree is made - available writable.</para> - - <para>Note that setting this to <option>yes</option> or - <option>state</option> will only work correctly with - operating systems in the container that can boot up with only - <filename>/usr</filename> mounted, and are able to populate - <filename>/var</filename> automatically, as - needed.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--settings=</option><replaceable>MODE</replaceable></term> - - <listitem><para>Controls whether - <command>systemd-nspawn</command> shall search for and use - additional per-container settings from - <filename>.nspawn</filename> files. Takes a boolean or the - special values <option>override</option> or - <option>trusted</option>.</para> - - <para>If enabled (the default), a settings file named after the - machine (as specified with the <option>--machine=</option> - setting, or derived from the directory or image file name) - with the suffix <filename>.nspawn</filename> is searched in - <filename>/etc/systemd/nspawn/</filename> and - <filename>/run/systemd/nspawn/</filename>. If it is found - there, its settings are read and used. If it is not found - there, it is subsequently searched in the same directory as the - image file or in the immediate parent of the root directory of - the container. In this case, if the file is found, its settings - will be also read and used, but potentially unsafe settings - are ignored. Note that in both these cases, settings on the - command line take precedence over the corresponding settings - from loaded <filename>.nspawn</filename> files, if both are - specified. Unsafe settings are considered all settings that - elevate the container's privileges or grant access to - additional resources such as files or directories of the - host. For details about the format and contents of - <filename>.nspawn</filename> files, consult - <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> - - <para>If this option is set to <option>override</option>, the - file is searched, read and used the same way, however, the order of - precedence is reversed: settings read from the - <filename>.nspawn</filename> file will take precedence over - the corresponding command line options, if both are - specified.</para> - - <para>If this option is set to <option>trusted</option>, the - file is searched, read and used the same way, but regardless - of being found in <filename>/etc/systemd/nspawn/</filename>, - <filename>/run/systemd/nspawn/</filename> or next to the image - file or container root directory, all settings will take - effect, however, command line arguments still take precedence - over corresponding settings.</para> - - <para>If disabled, no <filename>.nspawn</filename> file is read - and no settings except the ones on the command line are in - effect.</para></listitem> - </varlistentry> - - <varlistentry> - <term><option>--notify-ready=</option></term> - - <listitem><para>Configures support for notifications from the container's init process. - <option>--notify-ready=</option> takes a boolean (<option>no</option> and <option>yes</option>). - With option <option>no</option> systemd-nspawn notifies systemd - with a <literal>READY=1</literal> message when the init process is created. - With option <option>yes</option> systemd-nspawn waits for the - <literal>READY=1</literal> message from the init process in the container - before sending its own to systemd. For more details about notifications - see <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>).</para></listitem> - </varlistentry> - - <xi:include href="standard-options.xml" xpointer="help" /> - <xi:include href="standard-options.xml" xpointer="version" /> - </variablelist> - - </refsect1> - - <refsect1> - <title>Examples</title> - - <example> - <title>Build and boot a minimal BLAG distribution in a container</title> - - <programlisting># dnf -y --releasever=210k --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=blag --enablerepo=updates install systemd passwd dnf blag-release vim-minimal -# systemd-nspawn -bD /srv/mycontainer</programlisting> - - <para>This installs a minimal BLAG distribution into the - directory <filename noindex='true'>/srv/mycontainer/</filename> - and then boots an OS in a namespace container in it.</para> - </example> - - <example> - <title>Spawn a shell in a container of a minimal gNewSense Ucclia distribution</title> - - <programlisting># debootstrap --arch=amd64 ucclia ~/gnewsense-tree/ -# systemd-nspawn -D ~/gnewsense-tree/</programlisting> - - <para>This installs a minimal gNewSense unstable distribution into - the directory <filename>~/gnewsense-tree/</filename> and then - spawns a shell in a namespace container in it.</para> - </example> - - <example> - <title>Boot a minimal Parabola distribution in a container</title> - - <programlisting># pacstrap -c -d ~/parabola-tree/ base -# systemd-nspawn -bD ~/parabola-tree/</programlisting> - - <para>This installs a minimal Parabola distribution into the - directory <filename>~/parabola-tree/</filename> and then boots an OS - in a namespace container in it.</para> - </example> - - <example> - <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title> - - <programlisting># systemd-nspawn -D / -xb</programlisting> - - <para>This runs a copy of the host system in a - <literal>btrfs</literal> snapshot which is removed immediately - when the container exits. All file system changes made during - runtime will be lost on shutdown, hence.</para> - </example> - - <example> - <title>Run a container with SELinux sandbox security contexts</title> - - <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container -# 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> - </example> - </refsect1> - - <refsect1> - <title>Exit status</title> - - <para>The exit code of the program executed in the container is - returned.</para> - </refsect1> - - <refsect1> - <title>See Also</title> - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, - <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, - <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |