NAME | SYNOPSIS | DESCRIPTION | .NSPAWN FILE DISCOVERY | [EXEC] SECTION OPTIONS | [FILES] SECTION OPTIONS | [NETWORK] SECTION OPTIONS | SEE ALSO | NOTES | COLOPHON

SYSTEMD.NSPAWN(5)              systemd.nspawn              SYSTEMD.NSPAWN(5)

NAME         top

       systemd.nspawn - Container settings

SYNOPSIS         top

       /etc/systemd/nspawn/machine.nspawn

       /run/systemd/nspawn/machine.nspawn

       /var/lib/machines/machine.nspawn

DESCRIPTION         top

       An nspawn container settings file (suffix .nspawn) encodes additional
       runtime information about a local container, and is searched, read
       and used by systemd-nspawn(1) when starting a container. Files of
       this type are named after the containers they define settings for.
       They are optional, and only required for containers whose execution
       environment shall differ from the defaults. Files of this type mostly
       contain settings that may also be set on the systemd-nspawn command
       line, and make it easier to persistently attach specific settings to
       specific containers. The syntax of these files is inspired by
       .desktop files following the XDG Desktop Entry Specification[1],
       which in turn are inspired by Microsoft Windows .ini files.

       Boolean arguments used in these settings files can be written in
       various formats. For positive settings, the strings 1, yes, true and
       on are equivalent. For negative settings, the strings 0, no, false
       and off are equivalent.

       Empty lines and lines starting with # or ; are ignored. This may be
       used for commenting. Lines ending in a backslash are concatenated
       with the following line while reading and the backslash is replaced
       by a space character. This may be used to wrap long lines.

.NSPAWN FILE DISCOVERY         top

       Files are searched by appending the .nspawn suffix to the machine
       name of the container, as specified with the --machine= switch of
       systemd-nspawn, or derived from the directory or image file name.
       This file is first searched in /etc/systemd/nspawn/ and
       /run/systemd/nspawn/. If found in these directories, its settings are
       read and all of them take full effect (but are possibly overridden by
       corresponding command line arguments). If not found, the file will
       then be searched next to the image file or in the immediate parent of
       the root directory of the container. If the file is found there, only
       a subset of the settings will take effect however. All settings that
       possibly elevate privileges or grant additional access to resources
       of the host (such as files or directories) are ignored. To which
       options this applies is documented below.

       Persistent settings files created and maintained by the administrator
       (and thus trusted) should be placed in /etc/systemd/nspawn/, while
       automatically downloaded (and thus potentially untrusted) settings
       files are placed in /var/lib/machines/ instead (next to the container
       images), where their security impact is limited. In order to add
       privileged settings to .nspawn files acquired from the image vendor,
       it is recommended to copy the settings files into
       /etc/systemd/nspawn/ and edit them there, so that the privileged
       options become available. The precise algorithm for how the files are
       searched and interpreted may be configured with systemd-nspawn's
       --settings= switch, see systemd-nspawn(1) for details.

[EXEC] SECTION OPTIONS         top

       Settings files may include an "[Exec]" section, which carries various
       execution parameters:

       Boot=
           Takes a boolean argument, which defaults to off. If enabled,
           systemd-nspawn will automatically search for an init executable
           and invoke it. In this case, the specified parameters using
           Parameters= are passed as additional arguments to the init
           process. This setting corresponds to the --boot switch on the
           systemd-nspawn command line. This option may not be combined with
           ProcessTwo=yes. This option is the default if the
           systemd-nspawn@.service template unit file is used.

       ProcessTwo=
           Takes a boolean argument, which defaults to off. If enabled, the
           specified program is run as PID 2. A stub init process is run as
           PID 1. This setting corresponds to the --as-pid2 switch on the
           systemd-nspawn command line. This option may not be combined with
           Boot=yes.

       Parameters=
           Takes a space-separated list of arguments. This is either a
           command line, beginning with the binary name to execute, or – if
           Boot= is enabled – the list of arguments to pass to the init
           process. This setting corresponds to the command line parameters
           passed on the systemd-nspawn command line.

       Environment=
           Takes an environment variable assignment consisting of key and
           value, separated by "=". Sets an environment variable for the
           main process invoked in the container. This setting may be used
           multiple times to set multiple environment variables. It
           corresponds to the --setenv= command line switch.

       User=
           Takes a UNIX user name. Specifies the user name to invoke the
           main process of the container as. This user must be known in the
           container's user database. This corresponds to the --user=
           command line switch.

       WorkingDirectory=
           Selects the working directory for the process invoked in the
           container. Expects an absolute path in the container's file
           system namespace. This corresponds to the --chdir= command line
           switch.

       PivotRoot=
           Selects a directory to pivot to / inside the container when
           starting up. Takes a single path, or a pair of two paths
           separated by a colon. Both paths must be absolute, and are
           resolved in the container's file system namespace. This
           corresponds to the --pivot-root= command line switch.

       Capability=, DropCapability=
           Takes a space-separated list of Linux process capabilities (see
           capabilities(7) for details). The Capability= setting specifies
           additional capabilities to pass on top of the default set of
           capabilities. The DropCapability= setting specifies capabilities
           to drop from the default set. These settings correspond to the
           --capability= and --drop-capability= command line switches. Note
           that Capability= is a privileged setting, and only takes effect
           in .nspawn files in /etc/systemd/nspawn/ and /run/system/nspawn/
           (see above). On the other hand, DropCapability= takes effect in
           all cases.

       KillSignal=
           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 Boot= is
           used (on systemd-compatible init systems SIGRTMIN+3 triggers an
           orderly shutdown). For a list of valid signals, see signal(7).

       Personality=
           Configures the kernel personality for the container. This is
           equivalent to the --personality= switch.

       MachineID=
           Configures the 128-bit machine ID (UUID) to pass to the
           container. This is equivalent to the --uuid= command line switch.
           This option is privileged (see above).

       PrivateUsers=
           Configures support for usernamespacing. This is equivalent to the
           --private-users= command line switch, and takes the same options.
           This option is privileged (see above). This option is the default
           if the systemd-nspawn@.service template unit file is used.

       NotifyReady=
           Configures support for notifications from the container's init
           process. This is equivalent to use --notify-ready= command line
           switch, and takes the same options. See systemd-nspawn(1) for
           details about the specific options supported.

[FILES] SECTION OPTIONS         top

       Settings files may include a "[Files]" section, which carries various
       parameters configuring the file system of the container:

       ReadOnly=
           Takes a boolean argument, which defaults to off. If specified,
           the container will be run with a read-only file system. This
           setting corresponds to the --read-only command line switch.

       Volatile=
           Takes a boolean argument, or the special value "state". This
           configures whether to run the container with volatile state
           and/or configuration. This option is equivalent to --volatile=,
           see systemd-nspawn(1) for details about the specific options
           supported.

       Bind=, BindReadOnly=
           Adds a bind mount from the host into the container. Takes a
           single path, a pair of two paths separated by a colon, or a
           triplet of two paths plus an option string separated by colons.
           This option may be used multiple times to configure multiple bind
           mounts. This option is equivalent to the command line switches
           --bind= and --bind-ro=, see systemd-nspawn(1) for details about
           the specific options supported. This setting is privileged (see
           above).

       TemporaryFileSystem=
           Adds a "tmpfs" mount to the container. Takes a path or a pair of
           path and option string, separated by a colon. This option may be
           used multiple times to configure multiple "tmpfs" mounts. This
           option is equivalent to the command line switch --tmpfs=, see
           systemd-nspawn(1) for details about the specific options
           supported. This setting is privileged (see above).

       Overlay=, OverlayReadOnly=
           Adds an overlay mount point. Takes a colon-separated list of
           paths. This option may be used multiple times to configure
           multiple overlay mounts. This option is equivalent to the command
           line switches --overlay= and --overlay-ro=, see systemd-nspawn(1)
           for details about the specific options supported. This setting is
           privileged (see above).

       PrivateUsersChown=
           Configures whether the ownership of the files and directories in
           the container tree shall be adjusted to the UID/GID range used,
           if necessary and user namespacing is enabled. This is equivalent
           to the --private-users-chown command line switch. This option is
           privileged (see above).

[NETWORK] SECTION OPTIONS         top

       Settings files may include a "[Network]" section, which carries
       various parameters configuring the network connectivity of the
       container:

       Private=
           Takes a boolean argument, which defaults to off. If enabled, the
           container will run in its own network namespace and not share
           network interfaces and configuration with the host. This setting
           corresponds to the --private-network command line switch.

       VirtualEthernet=
           Takes a boolean argument. Configures whether to create a virtual
           Ethernet connection ("veth") between host and the container. This
           setting implies Private=yes. This setting corresponds to the
           --network-veth command line switch. This option is privileged
           (see above). This option is the default if the
           systemd-nspawn@.service template unit file is used.

       VirtualEthernetExtra=
           Takes a colon-separated pair of interface names. Configures an
           additional virtual Ethernet connection ("veth") between host and
           the container. The first specified name is the interface name on
           the host, the second the interface name in the container. The
           latter may be omitted in which case it is set to the same name as
           the host side interface. This setting implies Private=yes. This
           setting corresponds to the --network-veth-extra= command line
           switch, and maybe be used multiple times. It is independent of
           VirtualEthernet=. This option is privileged (see above).

       Interface=
           Takes a space-separated list of interfaces to add to the
           container. This option corresponds to the --network-interface=
           command line switch and implies Private=yes. This option is
           privileged (see above).

       MACVLAN=, IPVLAN=
           Takes a space-separated list of interfaces to add MACLVAN or
           IPVLAN interfaces to, which are then added to the container.
           These options correspond to the --network-macvlan= and
           --network-ipvlan= command line switches and imply Private=yes.
           These options are privileged (see above).

       Bridge=
           Takes an interface name. This setting implies VirtualEthernet=yes
           and Private=yes and has the effect that the host side of the
           created virtual Ethernet link is connected to the specified
           bridge interface. This option corresponds to the
           --network-bridge= command line switch. This option is privileged
           (see above).

       Zone=
           Takes a network zone name. This setting implies
           VirtualEthernet=yes and Private=yes and has the effect that the
           host side of the created virtual Ethernet link is connected to an
           automatically managed bridge interface named after the passed
           argument, prefixed with "vz-". This option corresponds to the
           --network-zone= command line switch. This option is privileged
           (see above).

       Port=
           Exposes a TCP or UDP port of the container on the host. This
           option corresponds to the --port= command line switch, see
           systemd-nspawn(1) for the precise syntax of the argument this
           option takes. This option is privileged (see above).

SEE ALSO         top

       systemd(1), systemd-nspawn(1), systemd.directives(7)

NOTES         top

        1. XDG Desktop Entry Specification
           http://standards.freedesktop.org/desktop-entry-spec/latest/

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see 
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨https://github.com/systemd/systemd.git⟩ on 2017-07-05.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 234                                                SYSTEMD.NSPAWN(5)

Pages that refer to this page: systemd-nspawn(1)systemd.directives(7)systemd.index(7)