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diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index df318d7a4..7d67472ff 100644
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -21,7 +21,8 @@
along with systemd; If not, see .
-->
-
+systemd-nspawn
@@ -69,7 +70,7 @@
systemd-nspawn may be used to
run a command or OS in a light-weight namespace
container. In many ways it is similar to
- chroot1,
+ chroot1,
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
@@ -97,15 +98,15 @@
involved with boot and systems management.In contrast to
- chroot1Â systemd-nspawn
+ chroot1Â systemd-nspawn
may be used to boot full Linux-based operating systems
in a container.Use a tool like
- yum8,
- debootstrap8,
+ yum8,
+ debootstrap8,
or
- pacman8
+ pacman8
to set up an OS directory tree suitable as file system
hierarchy for systemd-nspawn
containers.
@@ -135,27 +136,15 @@
As a safety check
systemd-nspawn will verify the
- existence of /etc/os-release in
- the container tree before starting the container (see
+ existence of /usr/lib/os-release
+ or /etc/os-release in the
+ container tree before starting the container (see
os-release5). 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.
-
- Incompatibility with Auditing
-
- Note that the kernel auditing subsystem is
- currently broken when used together with
- containers. We hence recommend turning it off entirely
- by booting with audit=0 on the
- kernel command line, or by turning it off at kernel
- build time. If auditing is enabled in the kernel,
- operating systems booted in an nspawn container might
- refuse log-in attempts.
-
-
Options
@@ -172,29 +161,111 @@
-
-
+
+
- Prints a short help
- text and exits.
+ Directory to use as
+ file system root for the container.
+
+ If neither
+ , nor
+ is specified
+ the directory is determined as
+ /var/lib/container/
+ suffixed by the machine name as
+ specified with
+ . If
+ neither ,
+ , nor
+ are
+ specified, the current directory will
+ be used. May not be specified together
+ with
+ .
-
-
- Prints a version string
- and exits.
+
+
+ Directory or
+ btrfs subvolume to
+ use as template for the container's
+ root directory. If this is specified
+ and the container's root directory (as
+ configured by
+ ) does
+ not yet exist it is created as
+ btrfs subvolume and
+ populated from this template
+ tree. Ideally, the specified template
+ path refers to the root of a
+ btrfs 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
+ btrfs subvolume (or
+ not even to a btrfs
+ 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
+ btrfs file system,
+ so that the btrfs
+ subvolume may be created. May not be
+ specified together with
+ or
+ .
-
-
+
+
+
+ If specified, the
+ container is run with a temporary
+ btrfs snapshot of
+ its root directory (as configured with
+ ), that
+ is removed immediately when the
+ container terminates. This option is
+ only supported if the root file system
+ is btrfs. May not
+ be specified together with
+ or
+ .
+
- Directory to use as
- file system root for the namespace
- container. If omitted, the current
- directory will be
- used.
+
+
+
+
+ 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 a GUID
+ Partition Table with a root partition
+ which is mounted as the root directory
+ of the container. Optionally, it 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 Discoverable
+ Partitions Specification. Any
+ other partitions, such as foreign
+ partitions, swap partitions or EFI
+ system partitions are not mounted. May
+ not be specified together with
+ ,
+ or
+ .
@@ -204,9 +275,12 @@
Automatically search
for an init binary and invoke it
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.
+ 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
+ .
@@ -214,13 +288,15 @@
- Run the command
- under specified user, create home
- directory and cd into it. As rest
- of systemd-nspawn, this is not
- the security feature and limits
- against accidental changes only.
-
+ 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.
@@ -229,13 +305,33 @@
Sets the machine name
for this container. This name may be
- used to identify this container on the
- host, 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 of the
- container is used.
+ used to identify this container during
+ its runtime (for example in tools like
+ machinectl1
+ 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
+ mode is
+ selected. If the root directory
+ selected is the host's root directory
+ the host's hostname is used as default
+ instead.
+
+
+
+
+
+ Set the specified UUID
+ for the container. The init system
+ will initialize
+ /etc/machine-id
+ from this if this file is not set yet.
+
@@ -243,59 +339,154 @@
Make the container
part of the specified slice, instead
- of the
+ of the default
machine.slice.
-
-
+
- Sets the mandatory
- access control (MAC/SELinux) file
- label to be used by virtual API file
- systems in the container.
-
+ 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
+
+ and configured with
+ . 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
+ .
-
-
+
+
+ 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
+
+ implies
+ . This
+ option may be used more than once to
+ add multiple network interfaces to the
+ container.
+
- Sets the mandatory
- access control (MAC/SELinux) label to be used by
- processes in the container.
-
+
+
+
+ Create a
+ macvlan interface
+ of the specified Ethernet network
+ interface and add it to the
+ container. A
+ macvlan 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 mv-. Note that
+
+ implies
+ . This
+ option may be used more than once to
+ add multiple network interfaces to the
+ container.
-
+
+
+ Create a virtual
+ Ethernet link
+ (veth) 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
+ ), prefixed
+ with ve-. The
+ container side of the Ethernet
+ link will be named
+ host0. Note that
+
+ implies
+ .
+
- Set the specified UUID
- for the container. The init system
- will initialize
- /etc/machine-id
- from this if this file is not set yet.
-
+
+
+
+ Adds the host side of
+ the Ethernet link created with
+ to the
+ specified bridge. Note that
+
+ implies
+ . If
+ this option is used, the host side of
+ the Ethernet link will use the
+ vb- prefix instead
+ of ve-.
-
+
+
+
+ If private networking
+ is enabled, maps an IP port on the
+ host onto an IP port on the
+ container. Takes a protocol specifier
+ (either tcp or
+ udp), 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
+ tcp is assumed.
+ The container port number and its
+ colon may be ommitted, in which case
+ the same port as the host port is
+ implied. This option is only supported
+ if private networking is used, such as
+ or
+ .
+
+
+
+
+
- Turn off networking in
- the container. This makes all network
- interfaces unavailable in the
- container, with the exception of the
- loopback device.
+ Sets the SELinux
+ security context to be used to label
+ processes in the container.
+
-
+
+
- Mount the root file
- system read-only for the
- container.
+ Sets the SELinux security
+ context to be used to label files in
+ the virtual API file systems in the
+ container.
+
@@ -305,7 +496,7 @@
additional capabilities to grant the
container. Takes a comma-separated
list of capability names, see
- capabilities7
+ capabilities7
for more information. Note that the
following capabilities will be granted
in any way: CAP_CHOWN,
@@ -321,7 +512,13 @@
CAP_SYS_PTRACE, CAP_SYS_TTY_CONFIG,
CAP_SYS_RESOURCE, CAP_SYS_BOOT,
CAP_AUDIT_WRITE,
- CAP_AUDIT_CONTROL.
+ CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN
+ is retained if
+ is
+ specified. If the special value
+ all is passed, all
+ capabilities are
+ retained.
@@ -345,7 +542,9 @@
versa). Takes one of
no,
host,
+ try-host,
guest,
+ try-guest,
auto. If
no, the journal is
not linked. If host,
@@ -359,8 +558,11 @@
guest file system (beneath
/var/log/journal/machine-id)
and the subdirectory is symlinked into the host
- at the same location. If
- auto (the default),
+ at the same location. try-host
+ and try-guest do the same
+ but do not fail if the host does not have
+ persistent journalling enabled.
+ If auto (the default),
and the right subdirectory of
/var/log/journal
exists, it will be bind mounted
@@ -379,7 +581,15 @@
Equivalent to
- .
+ .
+
+
+
+
+
+ Mount the root file
+ system read-only for the
+ container.
@@ -399,7 +609,31 @@
destination in the container. The
option
creates read-only bind
- mount.
+ mounts.
+
+
+
+
+
+ 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
+ /var as tmpfs, to
+ allow state-less systems, in
+ particular when combined with
+ .
@@ -416,86 +650,225 @@
more than once.
+
+
+
+ Allows the container
+ to share certain system facilities
+ with the host. More specifically, this
+ turns off PID namespacing, UTS
+ namespacing and IPC namespacing, and
+ thus allows the guest to see and
+ interact more easily with processes
+ outside of the container. Note that
+ using this option makes it impossible
+ to start up a full Operating System in
+ the container, as an init system
+ cannot operate in this mode. It is
+ only useful to run specific programs
+ or applications this way, without
+ involving an init system in the
+ container. This option implies
+ . This
+ option may not be combined with
+ .
+
+
+
+
+
+ Controls whether the
+ container is registered with
+ systemd-machined8. Takes
+ a boolean argument, defaults to
+ yes. 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
+ machinectl1
+ and shown by tools such as
+ ps1. If
+ the container does not run an init
+ system, it is recommended to set this
+ option to no. Note
+ that
+ implies
+ .
+
+
+
+
+
+
+ Instead of creating a
+ transient scope unit to run the
+ container in, simply register the
+ service or scope unit
+ systemd-nspawn has
+ been invoked in with
+ systemd-machined8. This
+ has no effect if
+ is
+ used. This switch should be used if
+ systemd-nspawn is
+ invoked from within a service unit,
+ and the service unit's sole purpose
+ is to run a single
+ systemd-nspawn
+ container. This option is not
+ available if run from a user
+ session.
+
+
+
+
+
+ Control the
+ architecture ("personality") reported
+ by
+ uname2
+ in the container. Currently, only
+ x86 and
+ x86-64 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.
+
+
Turns off any status
output by the tool itself. When this
- switch is used, then the only output
- by nspawn will be the console output
- of the container OS
- itself.
+ switch is used, the only output
+ from nspawn will be the console output
+ of the container OS itself.
+
+
+
+ =MODE
+
+ Boots the container in
+ volatile mode. When no mode parameter
+ is passed or when mode is specified as
+ yes full volatile
+ mode is enabled. This means the root
+ directory is mounted as mostly
+ unpopulated tmpfs
+ instance, and
+ /usr from the OS
+ tree is mounted into it, read-only
+ (the system thus starts up with
+ read-only OS resources, but pristine
+ state and configuration, any changes
+ to the either are lost on
+ shutdown). When the mode parameter is
+ specified as state
+ the OS tree is mounted read-only, but
+ /var is mounted
+ as tmpfs instance
+ into it (the system thus starts up
+ with read-only OS resources and
+ configuration, but pristine state, any
+ changes to the latter are lost on
+ shutdown). When the mode parameter is
+ specified as no
+ (the default) the whole OS tree is
+ made available writable.
+
+ Note that setting this to
+ yes or
+ state will only
+ work correctly with operating systems
+ in the container that can boot up with
+ only /usr
+ mounted, and are able to populate
+ /var
+ automatically, as
+ needed.
+
+
- Example 1
+ Examples
+
+ Boot a minimal Fedora distribution in a container
- # yum -y --releasever=19 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
+ # yum -y --releasever=21 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
# systemd-nspawn -bD /srv/mycontainer
- This installs a minimal Fedora distribution into
- the directory /srv/mycontainer/ and
- then boots an OS in a namespace container in
- it.
-
+ This installs a minimal Fedora distribution into
+ the directory /srv/mycontainer/ and
+ then boots an OS in a namespace container in
+ it.
+
-
- Example 2
+
+ Spawn a shell in a container of a minimal Debian unstable distribution
- # debootstrap --arch=amd64 unstable ~/debian-tree/
+ # debootstrap --arch=amd64 unstable ~/debian-tree/
# systemd-nspawn -D ~/debian-tree/
- This installs a minimal Debian unstable
- distribution into the directory
- ~/debian-tree/ and then spawns a
- shell in a namespace container in it.
-
+ This installs a minimal Debian unstable
+ distribution into the directory
+ ~/debian-tree/ and then spawns a
+ shell in a namespace container in it.
+
-
- Example 3
+
+ Boot a minimal Arch Linux distribution in a container
- # pacstrap -c -d ~/arch-tree/ base
+ # pacstrap -c -d ~/arch-tree/ base
# systemd-nspawn -bD ~/arch-tree/
- This installs a mimimal Arch Linux distribution into
- the directory ~/arch-tree/ and then
- boots an OS in a namespace container in it.
-
+ This installs a mimimal Arch Linux distribution into
+ the directory ~/arch-tree/ and then
+ boots an OS in a namespace container in it.
+
-
- Example 4
+
+ Enable Arch Linux container on boot
- # mv ~/arch-tree /var/lib/container/arch
+ # mv ~/arch-tree /var/lib/container/arch
# systemctl enable systemd-nspawn@arch.service
# systemctl start systemd-nspawn@arch.service
- This makes the Arch Linux container part of the
- multi-user.target on the host.
-
-
+ This makes the Arch Linux container part of the
+ multi-user.target on the host.
+
+
-
- Example 5
+
+ Boot into an ephemeral btrfs snapshot of the host system
- # btrfs subvolume snapshot / /.tmp
-# systemd-nspawn --private-network -D /.tmp -b
+ # systemd-nspawn -D / -xb
- This runs a copy of the host system in a
- btrfs snapshot.
-
+ This runs a copy of the host system in a
+ btrfs snapshot which is
+ removed immediately when the container
+ exits. All file system changes made during
+ runtime will be lost on shutdown,
+ hence.
+
-
- Example 6
+
+ Run a container with SELinux sandbox security contexts
- # chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container
+ # 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
-
- This runs a container with SELinux sandbox labels.
+
@@ -509,12 +882,13 @@
See Alsosystemd1,
- chroot1,
- yum8,
- debootstrap8,
- pacman8,
+ chroot1,
+ yum8,
+ debootstrap8,
+ pacman8,
systemd.slice5,
- machinectl1
+ machinectl1,
+ btrfs8