[EXEC] SECTION OPTIONS¶
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 specified by default in the
systemd-nspawn@.service template unit.
Ephemeral=
Takes a boolean argument, which defaults to off, If
enabled, the container is run with a temporary snapshot of its file system
that is removed immediately when the container terminates. This is equivalent
to the
--ephemeral command line switch. See
systemd-nspawn(1)
for details about the specific options supported.
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 whitespace-separated list of arguments. Single
("'") and double (""") quotes may be used around
arguments with whitespace. 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.
Note: Boot=no, Parameters=a b "c c" is the
same as systemd-nspawn a b "c c", and Boot=yes,
Parameters=b 'c c' is the same as systemd-nspawn --boot b 'c
c'.
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. If the
special value "all" is passed, all capabilities are retained (or
dropped).
These settings change the bounding set of capabilities which also
limits the ambient capabilities as given with the
AmbientCapability=.
AmbientCapability=
Takes a space-separated list of Linux process
capabilities (see
capabilities(7) for details). The
AmbientCapability= setting specifies capabilities which will be passed
to the started program in the inheritable and ambient capability sets. This
will grant these capabilities to this process. This setting correspond to the
--ambient-capability= command line switch.
The value "all" is not supported for this setting.
The setting of AmbientCapability= must be covered by the
bounding set settings which were established by Capability= and
DropCapability=.
Note that AmbientCapability= is a privileged setting (see
above).
NoNewPrivileges=
Takes a boolean argument that controls the
PR_SET_NO_NEW_PRIVS flag for the container payload. This is equivalent
to the
--no-new-privileges= command line switch. See
systemd-nspawn(1) for details.
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 the
--notify-ready= command line
switch, and takes the same parameters. See
systemd-nspawn(1) for
details about the specific options supported.
SystemCallFilter=
Configures the system call filter applied to containers.
This is equivalent to the
--system-call-filter= command line switch,
and takes the same list parameter. See
systemd-nspawn(1) for
details.
LimitCPU=, LimitFSIZE=, LimitDATA=,
LimitSTACK=, LimitCORE=, LimitRSS=,
LimitNOFILE=, LimitAS=, LimitNPROC=,
LimitMEMLOCK=, LimitLOCKS=, LimitSIGPENDING=,
LimitMSGQUEUE=, LimitNICE=, LimitRTPRIO=,
LimitRTTIME=
Configures various types of resource limits applied to
containers. This is equivalent to the
--rlimit= command line switch,
and takes the same arguments. See
systemd-nspawn(1) for details.
OOMScoreAdjust=
Configures the OOM score adjustment value. This is
equivalent to the
--oom-score-adjust= command line switch, and takes
the same argument. See
systemd-nspawn(1) for details.
CPUAffinity=
Configures the CPU affinity. This is equivalent to the
--cpu-affinity= command line switch, and takes the same argument. See
systemd-nspawn(1) for details.
Hostname=
Configures the kernel hostname set for the container.
This is equivalent to the
--hostname= command line switch, and takes
the same argument. See
systemd-nspawn(1) for details.
ResolvConf=
Configures how /etc/resolv.conf in the container shall be
handled. This is equivalent to the
--resolv-conf= command line switch,
and takes the same argument. See
systemd-nspawn(1) for details.
Timezone=
Configures how /etc/localtime in the container shall be
handled. This is equivalent to the
--timezone= command line switch, and
takes the same argument. See
systemd-nspawn(1) for details.
LinkJournal=
Configures how to link host and container journal setups.
This is equivalent to the
--link-journal= command line switch, and
takes the same parameter. See
systemd-nspawn(1) for details.
SuppressSync=
Configures whether to suppress disk synchronization for
the container payload. This is equivalent to the
--suppress-sync=
command line switch, and takes the same parameter. See
systemd-nspawn(1) for details.
[FILES] SECTION OPTIONS¶
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).
BindUser=
Binds a user from the host into the container. This
option is equivalent to the command line switch
--bind-user=, 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).
Inaccessible=
Masks the specified file or directory in the container,
by over-mounting it with an empty file node of the same type with the most
restrictive access mode. Takes a file system path as argument. This option may
be used multiple times to mask multiple files or directories. This option is
equivalent to the command line switch
--inaccessible=, 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).
PrivateUsersOwnership=
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-ownership= command line switch. This option is
privileged (see above).
[NETWORK] SECTION OPTIONS¶
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=. Note that this option is
unrelated to the Bridge= setting below, and thus any connections
created this way are not automatically added to any bridge device on the host
side. 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).