X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.unit.xml;h=6a5eefb6dbd09e34d66563caec1a28139f6a50c6;hp=d447c3a0a52dd471c8637a4aef5e3f95aefe1dac;hb=12f25b6e741bc8394f63778598fc203e3f6d4ae6;hpb=28cf382a0afd10d0e2a71d152f0df4909e90d159
diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index d447c3a0a..6a5eefb6d 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -1,6 +1,9 @@
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+
+%entities;
+]>
@@ -44,20 +47,32 @@
systemd.unit
- systemd unit configuration files
+ Unit configuration
- systemd.service,
- systemd.socket,
- systemd.device,
- systemd.mount,
- systemd.automount,
- systemd.swap,
- systemd.target,
- systemd.path,
- systemd.timer,
- systemd.snapshot
+ service.service,
+ socket.socket,
+ device.device,
+ mount.mount,
+ automount.automount,
+ swap.swap,
+ target.target,
+ path.path,
+ timer.timer,
+ snapshot.snapshot
+
+ /etc/systemd/system/*
+/run/systemd/system/*
+/usr/lib/systemd/system/*
+...
+
+
+ /etc/systemd/user/*
+/run/systemd/user/*
+/usr/lib/systemd/user/*
+...
+
@@ -66,7 +81,7 @@
A unit configuration file encodes information
about a service, a socket, a device, a mount point, an
automount point, a swap file or partition, a start-up
- target, a file system path or a timer controlled and
+ target, a file system path, or a timer controlled and
supervised by
systemd1. The
syntax is inspired by .ini files.
- This man pages lists the common configuration
+ This man page lists the common configuration
options of all the unit types. These options need to
- be configured in the [Unit] resp. [Install]
- section of the unit files.
+ be configured in the [Unit] or [Install]
+ sections of the unit files.In addition to the generic [Unit] and [Install]
- sections described here, each unit should have a
+ sections described here, each unit may have a
type-specific section, e.g. [Service] for a service
unit. See the respective man pages for more
- information.
+ information:
+ systemd.service5,
+ systemd.socket5,
+ systemd.device5,
+ systemd.mount5,
+ systemd.automount5,
+ systemd.swap5,
+ systemd.target5,
+ systemd.path5,
+ systemd.timer5,
+ systemd.snapshot5.
+
+
+ Unit files are loaded from a set of paths
+ determined during compilation, described in the next section.
+ Unit files may contain additional options on top
of those listed here. If systemd encounters an unknown
@@ -106,12 +136,14 @@
Time span values encoded in unit files can be
written in various formats. A stand-alone number
specifies a time in seconds. If suffixed with a time
- unit, the unit is honored. A concatenation of
- multiple values with units is supported, in which case
- the values are added up. Example: "50" refers to 50
+ unit, the unit is honored. A concatenation of multiple
+ values with units is supported, in which case the
+ values are added up. Example: "50" refers to 50
seconds; "2min 200ms" refers to 2 minutes plus 200
milliseconds, i.e. 120200ms. The following time units
- are understood: s, min, h, d, w, ms, us.
+ are understood: s, min, h, d, w, ms, us. For details
+ see
+ systemd.time7.Empty lines and lines starting with # or ; are
ignored. This may be used for commenting. Lines ending
@@ -119,43 +151,53 @@
line while reading and the backslash is replaced by a
space character. This may be used to wrap long lines.
- If a line starts with
- followed by a file name, the specified file will be
- read as if its contents were listed in place of the
- directive.
-
Along with a unit file
- foo.service a directory
+ foo.service the directory
foo.service.wants/ may exist. All
- units symlinked from such a directory are implicitly
- added as dependencies of type
+ unit files symlinked from such a directory are
+ implicitly added as dependencies of type
Wanted= to the unit. This is useful
to hook units into the start-up of other units,
- without having to modify their unit configuration
- files. For details about the semantics of
- Wanted= see below. The preferred
- way to create symlinks in the
- .wants/ directory of a service is
- with the enable command of the
+ without having to modify their unit files. For details
+ about the semantics of Wanted= see
+ below. The preferred way to create symlinks in the
+ .wants/ directory of a unit file
+ is with the enable command of the
systemctl1
tool which reads information from the [Install]
- section of unit files. (See below.) A similar
+ section of unit files (see below). A similar
functionality exists for Requires=
type dependencies as well, the directory suffix is
.requires/ in this case.
+ Along with a unit file
+ foo.service a directory
+ foo.service.d/ may exist. All
+ files with the suffix .conf from
+ this directory will be parsed after the file itself is
+ parsed. This is useful to alter or add configuration
+ settings to a unit, without having to modify their
+ unit files. Make sure that the file that is included
+ has the appropriate section headers before any
+ directive.
+
+ If a line starts with
+ followed by a file name, the specified file will be
+ parsed at this point. Make sure that the file that is
+ included has the appropriate section headers before
+ any directives.
+
Note that while systemd offers a flexible
dependency system between units it is recommended to
- use this functionality only sparsely and instead rely
+ use this functionality only sparingly and instead rely
on techniques such as bus-based or socket-based
- activation which makes dependencies implicit, which
- both results in a simpler and more flexible
- system.
+ activation which make dependencies implicit, resulting
+ in a both simpler and more flexible system.
Some unit names reflect paths existing in the
- file system name space. Example: a device unit
+ file system namespace. Example: a device unit
dev-sda.device refers to a device
- with the device node /dev/sda in
+ with the device node /dev/sda in
the file system namespace. If this applies a special
way to escape the path name is used, so that the
result is usable as part of a file name. Basically,
@@ -180,22 +222,12 @@
and no file by that name is found, systemd will look
for getty@.service and
instantiate a service from that configuration file if
- it is found. To refer to the instance string from
+ it is found.
+
+ To refer to the instance string from
within the configuration file you may use the special
%i specifier in many of the
- configuration options. Other specifiers that may be
- used are %n, %N,
- %p, %P,
- %I and %f, for
- the full unit name, the unescaped unit name, the
- prefix name, the unescaped prefix name, the unescaped
- instance name and the unescaped filename,
- respectively. The unescaped filename is either the
- unescaped instance name (if set) with / prepended (if
- necessary), or the prefix name similarly prepended
- with /. The prefix name here refers to the string
- before the @, i.e. "getty" in the example above, where
- "tty3" is the instance name.
+ configuration options. See below for details.
If a unit file is empty (i.e. has the file size
0) or is symlinked to /dev/null
@@ -209,6 +241,125 @@
Interface
Stability Promise.
+
+
+
+
+ Unit Load Path
+
+ Unit files are loaded from a set of paths
+ determined during compilation, described in the two
+ tables below. Unit files found in directories higher
+ in the hierarchy override files with the same name
+ lower in the hierarchy, thus allowing overrides.
+
+
+ When systemd is running in user mode
+ () and the variable
+ $SYSTEMD_UNIT_PATH is set, this
+ contents of this variable overrides the unit load
+ path.
+
+
+
+
+ Load path when running in system mode (<option>--system</option>).
+
+
+
+
+
+
+
+ Path
+ Description
+
+
+
+
+ /run/systemd/generator.early
+ Generated units (early)
+
+
+ /etc/systemd/system
+ Local configuration
+
+
+ /run/systemd/systemd
+ Volatile units
+
+
+ /run/systemd/generator
+ Generated units (middle)
+
+
+ /usr/local/lib/systemd/system
+ Units for local packages
+
+
+ /usr/lib/systemd/system
+ Units for installed packages
+
+
+ /run/systemd/generator.late
+ Generated units (late)
+
+
+
+
+
+
+
+ Load path when running in session mode (<option>--user</option>).
+
+
+
+
+
+
+
+ Path
+ Description
+
+
+
+
+ /tmp/systemd-generator.early.XXXXXX
+ Generated units (early)
+
+
+ /etc/systemd/user
+ Local configuration
+
+
+ /run/systemd/user
+ Volatile units
+
+
+ /tmp/systemd-generator.XXXXXX
+ Generated units (middle)
+
+
+ /usr/local/lib/systemd/user
+ Units for local packages
+
+
+ /usr/lib/systemd/user
+ Units for installed packages
+
+
+ /tmp/systemd-generator.late.XXXXXX
+ Generated units (late)
+
+
+
+
+
+ Additional units might be loaded into systemd
+ ("linked") from directories not on the unit load
+ path. See the link command for
+ systemctl1.
+
@@ -218,7 +369,7 @@
carries generic information about the unit that is not
dependent on the type of unit:
-
+ Description=
@@ -229,6 +380,36 @@
name.
+
+ Documentation=
+ A space separated list
+ of URIs referencing documentation for
+ this unit or its
+ configuration. Accepted are only URIs
+ of the types
+ http://,
+ https://,
+ file:,
+ info:,
+ man:. For more
+ information about the syntax of these
+ URIs see
+ uri7. The
+ URIs should be listed in order of
+ relevance, starting with the most
+ relevant. It is a good idea to first
+ reference documentation that explains
+ what the unit's purpose is, followed
+ by how it is configured, followed by
+ any other related documentation. This
+ option may be specified more than once
+ in which case the specified list of
+ URIs is merged. If the empty string is
+ assigned to this option the list is
+ reset and all prior assignments will
+ have no effect.
+
+
Requires=
@@ -266,7 +447,15 @@
Requires= in order
to achieve a system that is more
robust when dealing with failing
- services.
+ services.
+
+ Note that dependencies of this
+ type may also be configured outside of
+ the unit configuration file by
+ adding a symlink to a
+ .requires/ directory
+ accompanying the unit file. For
+ details see above.
@@ -298,7 +487,7 @@
Similar to
Requires=
- resp. RequiresOverridable=. However,
+ and RequiresOverridable=, respectively. However,
if a unit listed here is not started
already it will not be started and the
transaction fails
@@ -318,7 +507,9 @@
the transaction as a whole. This is
the recommended way to hook start-up
of one unit to the start-up of another
- unit. Note that dependencies of this
+ unit.
+
+ Note that dependencies of this
type may also be configured outside of
the unit configuration file by
adding a symlink to a
@@ -328,12 +519,12 @@
- BindTo=
+ BindsTo=Configures requirement
dependencies, very similar in style to
Requires=, however
- in addition to this behaviour it also
+ in addition to this behavior it also
declares that this unit is stopped
when any of the units listed suddenly
disappears. Units can suddenly,
@@ -344,6 +535,21 @@
systemd.
+
+ PartOf=
+
+ Configures dependencies
+ similar to Requires=,
+ but limited to stopping and restarting
+ of units. When systemd stops or restarts
+ the units listed here, the action is
+ propagated to this unit.
+ Note that this is a one way dependency -
+ changes to this unit do not affect the
+ listed units.
+
+
+
Conflicts=
@@ -429,7 +635,7 @@
Before=. If two
units have no ordering dependencies
between them they are shut down
- resp. started up simultaneously, and
+ or started up simultaneously, and
no ordering takes
place.
@@ -444,6 +650,72 @@
state.
+
+ PropagatesReloadTo=
+ ReloadPropagatedFrom=
+
+ Lists one or more
+ units where reload requests on the
+ unit will be propagated to/on the
+ other unit will be propagated
+ from. Issuing a reload request on a
+ unit will automatically also enqueue a
+ reload request on all units that the
+ reload request shall be propagated to
+ via these two
+ settings.
+
+
+
+ RequiresMountsFor=
+
+ Takes a space
+ separated list of absolute paths. Automatically
+ adds dependencies of type
+ Requires= and
+ After= for all
+ mount units required to access the
+ specified path.
+
+
+
+ OnFailureIsolate=
+
+ Takes a boolean
+ argument. If the
+ unit listed in
+ OnFailure= will be
+ enqueued in isolation mode, i.e. all
+ units that are not its dependency will
+ be stopped. If this is set only a
+ single unit may be listed in
+ OnFailure=. Defaults
+ to
+ .
+
+
+
+ IgnoreOnIsolate=
+
+ Takes a boolean
+ argument. If
+ this unit will not be stopped when
+ isolating another unit. Defaults to
+ .
+
+
+
+ IgnoreOnSnapshot=
+
+ Takes a boolean
+ argument. If
+ this unit will not be included in
+ snapshots. Defaults to
+ for device and
+ snapshot units,
+ for the others.
+
+
StopWhenUnneeded=
@@ -469,13 +741,13 @@
Takes a boolean
argument. If
this unit can only be activated
- (resp. deactivated) indirectly. In
+ or deactivated indirectly. In
this case explicit start-up
- (resp. termination) requested by the
+ or termination requested by the
user is denied, however if it is
- started (resp. stopped) as a
+ started or stopped as a
dependency of another unit, start-up
- (resp. termination) will succeed. This
+ or termination will succeed. This
is mostly a safety feature to ensure
that the user does not accidentally
activate units that are not intended
@@ -561,35 +833,106 @@
ConditionPathExists=
+ ConditionPathExistsGlob=
+ ConditionPathIsDirectory=
+ ConditionPathIsSymbolicLink=
+ ConditionPathIsMountPoint=
+ ConditionPathIsReadWrite=ConditionDirectoryNotEmpty=
+ ConditionFileNotEmpty=
+ ConditionFileIsExecutable=ConditionKernelCommandLine=ConditionVirtualization=
+ ConditionSecurity=
+ ConditionCapability=
+ ConditionHost=
+ ConditionACPower=ConditionNull=Before starting a unit
verify that the specified condition is
- true. With
+ true. If it is not true the starting
+ of the unit will be skipped, however
+ all ordering dependencies of it are
+ still respected. A failing condition
+ will not result in the unit being
+ moved into a failure state. The
+ condition is checked at the time the
+ queued start job is to be
+ executed.
+
+ With
ConditionPathExists=
- a file existance condition can be
+ a file existence condition is
checked before a unit is started. If
the specified absolute path name does
- not exist startup of a unit will not
- actually happen, however the unit is
- still useful for ordering purposes in
- this case. The condition is checked at
- the time the queued start job is to be
- executed. If the absolute path name
- passed to
+ not exist the condition will
+ fail. If the absolute path name passed
+ to
ConditionPathExists=
is prefixed with an exclamation mark
- (!), the test is negated, and the unit
- only started if the path does not
- exist. ConditionDirectoryNotEmpty=
+ ('!'), the test is negated, and the unit
+ is only started if the path does not
+ exist.
+
+ ConditionPathExistsGlob=
+ is similar to
+ ConditionPathExists=,
+ but checks for the existence of at
+ least one file or directory matching
+ the specified globbing pattern.
+
+ ConditionPathIsDirectory=
+ is similar to
+ ConditionPathExists=
+ but verifies whether a certain path
+ exists and is a
+ directory.
+
+ ConditionPathIsSymbolicLink=
+ is similar to
+ ConditionPathExists=
+ but verifies whether a certain path
+ exists and is a symbolic
+ link.
+
+ ConditionPathIsMountPoint=
is similar to
ConditionPathExists=
- but verifies whether a certain path is
+ but verifies whether a certain path
+ exists and is a mount
+ point.
+
+ ConditionPathIsReadWrite=
+ is similar to
+ ConditionPathExists=
+ but verifies whether the underlying
+ file system is readable and writable
+ (i.e. not mounted
+ read-only).
+
+ ConditionDirectoryNotEmpty=
+ is similar to
+ ConditionPathExists=
+ but verifies whether a certain path
exists and is a non-empty
- directory. Similarly
+ directory.
+
+ ConditionFileNotEmpty=
+ is similar to
+ ConditionPathExists=
+ but verifies whether a certain path
+ exists and refers to a regular file
+ with a non-zero size.
+
+ ConditionFileIsExecutable=
+ is similar to
+ ConditionPathExists=
+ but verifies whether a certain path
+ exists, is a regular file and marked
+ executable.
+
+ Similar,
ConditionKernelCommandLine=
may be used to check whether a
specific kernel command line option is
@@ -597,39 +940,112 @@
exclamation mark unset). The argument
must either be a single word, or an
assignment (i.e. two words, separated
- by the equality sign). In the former
+ '='). In the former
case the kernel command line is
searched for the word appearing as is,
or as left hand side of an
assignment. In the latter case the
exact assignment is looked for with
right and left hand side
- matching. ConditionVirtualization=
+ matching.
+
+ ConditionVirtualization=
may be used to check whether the
system is executed in a virtualized
environment and optionally test
whether it is a specific
implementation. Takes either boolean
value to check if being executed in
- any virtual environment or one of the
+ any virtualized environment, or one of
+ vm and
+ container to test
+ against a generic type of
+ virtualization solution, or one of
qemu,
kvm,
vmware,
microsoft,
oracle,
xen,
- pidns,
- openvz to test
- against a specific implementation. The
+ bochs,
+ chroot,
+ openvz,
+ lxc,
+ lxc-libvirt,
+ systemd-nspawn to
+ test against a specific
+ implementation. If multiple
+ virtualization technologies are nested
+ only the innermost is considered. The
test may be negated by prepending an
- exclamation mark. Finally,
+ exclamation mark.
+
+ ConditionSecurity=
+ may be used to check whether the given
+ security module is enabled on the
+ system. Currently the recognized values
+ values are selinux,
+ apparmor,
+ ima and
+ smack.
+ The test may be negated by prepending
+ an exclamation
+ mark.
+
+ ConditionCapability=
+ may be used to check whether the given
+ capability exists in the capability
+ bounding set of the service manager
+ (i.e. this does not check whether
+ capability is actually available in
+ the permitted or effective sets, see
+ capabilities7
+ for details). Pass a capability name
+ such as CAP_MKNOD,
+ possibly prefixed with an exclamation
+ mark to negate the check.
+
+ ConditionHost=
+ may be used to match against the
+ host name or machine ID of the
+ host. This either takes a host name
+ string (optionally with shell style
+ globs) which is tested against the
+ locally set host name as returned by
+ gethostname2,
+ or a machine ID formatted as string
+ (see
+ machine-id5).
+ The test may be negated by prepending
+ an exclamation mark.
+
+ ConditionACPower=
+ may be used to check whether the
+ system has AC power, or is exclusively
+ battery powered at the time of
+ activation of the unit. This takes a
+ boolean argument. If set to
+ true the condition
+ will hold only if at least one AC
+ connector of the system is connected
+ to a power source, or if no AC
+ connectors are known. Conversely, if
+ set to false the
+ condition will hold only if there is
+ at least one AC connector known and
+ all AC connectors are disconnected
+ from a power source.
+
+ Finally,
ConditionNull= may
be used to add a constant condition
check value to the unit. It takes a
boolean argument. If set to
false the condition
will always fail, otherwise
- succeed. If multiple conditions are
+ succeed.
+
+ If multiple conditions are
specified the unit will be executed if
all of them apply (i.e. a logical AND
is applied). Condition checks can be
@@ -644,36 +1060,27 @@
prefix an argument with the pipe
symbol and an exclamation mark the
pipe symbol must be passed first, the
- exclamation second.
+ exclamation second. Except for
+ ConditionPathIsSymbolicLink=,
+ all path checks follow symlinks. If
+ any of these options is assigned the
+ empty string the list of conditions is
+ reset completely, all previous
+ condition settings (of any kind) will
+ have no effect.
- Names=
-
- Additional names for
- this unit. The names listed here must
- have the same suffix (i.e. type) as
- the unit file name. This option may be
- specified more than once, in which
- case all listed names are used. Note
- that this option is different from the
- Alias= option from
- the [Install] section mentioned
- below. See below for details. Note
- that in almost all cases this option
- is not what you want. A symlink alias
- in the file system is generally
- preferable since it can be used as
- lookup key. If a unit with a symlinked
- alias name is not loaded and needs to
- be it is easily found via the
- symlink. However, if a unit with an
- alias name configured with this
- setting is not loaded it will not be
- discovered. This settings' only use is
- in conjunction with service
- instances.
-
+ SourcePath=
+ A path to a
+ configuration file this unit has been
+ generated from. This is primarily
+ useful for implementation of generator
+ tools that convert configuration from
+ an external configuration file format
+ into native unit files. Thus
+ functionality should not be used in
+ normal units.
@@ -687,7 +1094,7 @@
systemctl1
tool during installation of a unit:
-
+ Alias=
@@ -701,38 +1108,17 @@
time,
systemctl enable
will create symlinks from these names
- to the unit file name. Note that this
- is different from the
- Names= option from
- the [Unit] section mentioned above:
- The names from
- Names= apply
- unconditionally if the unit is
- loaded. The names from
- Alias= apply only
- if the unit has actually been
- installed with the
- systemctl enable
- command. Also, if systemd searches for a
- unit, it will discover symlinked alias
- names as configured with
- Alias=, but not
- names configured with
- Names= only. It is
- a common pattern to list a name in
- both options. In this case, a unit
- will be active under all names if
- installed, but also if not installed
- but requested explicitly under its
- main name.
+ to the unit file name.
WantedBy=
+ RequiredBy=Installs a symlink in
the .wants/
- subdirectory for a unit. This has the
+ or .requires/
+ subdirectory for a unit, respectively. This has the
effect that when the listed unit name
is activated the unit listing it is
activated
@@ -748,17 +1134,145 @@
Also=Additional units to
- install when this unit is
- installed. If the user requests
- installation of a unit with this
- option configured,
+ install/deinstall when this unit is
+ installed/deinstalled. If the user
+ requests installation/deinstallation
+ of a unit with this option configured,
systemctl enable
- will automatically install units
- listed in this option as
+ and systemctl
+ disable will automatically
+ install/uninstall units listed in this option as
well.
+ The following specifiers are interpreted in the
+ Install section: %n, %N, %p, %i, %U, %u, %m, %H, %b.
+ For their meaning see the next section.
+
+
+
+
+ Specifiers
+
+ Many settings resolve specifiers which may be
+ used to write generic unit files referring to runtime
+ or unit parameters that are replaced when the unit
+ files are loaded. The following specifiers are
+ understood:
+
+
+ Specifiers available in unit files
+
+
+
+
+
+
+ Specifier
+ Meaning
+ Details
+
+
+
+
+ %n
+ Full unit name
+
+
+
+ %N
+ Unescaped full unit name
+
+
+
+ %p
+ Prefix name
+ For instantiated units this refers to the string before the @. For non-instantiated units this refers to to the name of the unit with the type suffix removed.
+
+
+ %P
+ Unescaped prefix name
+
+
+
+ %i
+ Instance name
+ For instantiated units: this is the string between the @ character and the suffix.
+
+
+ %I
+ Unescaped instance name
+
+
+
+ %f
+ Unescaped file name
+ This is either the unescaped instance name (if applicable) with / prepended (if applicable), or the prefix name similarly prepended with /.
+
+
+ %c
+ Control group path of the unit
+
+
+
+ %r
+ Root control group path where units are placed.
+ For system instances this usually resolves to /system, except in containers, where the path might be prefixed with the container's root control group.
+
+
+ %R
+ Parent directory of the control group path where units are placed.
+ For system instances this usually resolves to /, except in containers, where this resolves to the container's root directory. This specifier is particularly useful in the ControlGroup= setting (see systemd.exec5).
+
+
+ %t
+ Runtime socket dir
+ This is either /run (for the system manager) or $XDG_RUNTIME_DIR (for user managers).
+
+
+ %u
+ User name
+ This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance.
+
+
+ %U
+ User UID
+ This is the UID of the configured user of the unit, or (if none is set) the user running the systemd instance.
+
+
+ %h
+ User home directory
+ This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance.
+
+
+ %s
+ User shell
+ This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance. If the user is root (UID equal to 0), the shell configured in account database is ignored and /bin/sh is always used.
+
+
+ %m
+ Machine ID
+ The machine ID of the running system, formatted as string. See machine-id5 for more information.
+
+
+ %b
+ Boot ID
+ The boot ID of the running system, formatted as string. See random4 for more information.
+
+
+ %H
+ Host name
+ The host name of the running system.
+
+
+ %%
+ Escaped %
+ Single percent sign.
+
+
+
+