<refsect1>
<title>Description</title>
- <para>A configuration file ending in .service encodes
- information about a process controlled and supervised
- by systemd.</para>
+ <para>A unit configuration file whose name ends in
+ <filename>.service</filename> encodes information
+ about a process controlled and supervised by
+ systemd.</para>
<para>This man page lists the configuration options
specific to this unit type. See
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for the common options of all unit configuration
- files.</para>
+ files. The common configuration items are configured
+ in the generic <literal>[Unit]</literal> and
+ <literal>[Install]</literal> sections. The service
+ specific configuration options are configured in the
+ <literal>[Service]</literal> section.</para>
+
+ <para>Additional options are listed in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which define the execution environment the commands
+ are executed in.</para>
+
+ <para>Unless <varname>DefaultDependencies=</varname>
+ is set to <option>false</option>, service units will
+ implicitly have dependencies of type
+ <varname>Requires=</varname> and
+ <varname>After=</varname> on
+ <filename>basic.target</filename> as well as
+ dependencies of type <varname>Conflicts=</varname> and
+ <varname>Before=</varname> on
+ <filename>shutdown.target</filename>. These ensure
+ that normal service units pull in basic system
+ initialization, and are terminated cleanly prior to
+ system shutdown. Only services involved with early
+ boot or late system shutdown should disable this
+ option.</para>
+
+ <para>If a service is requested under a certain name
+ but no unit configuration file is found, systemd looks
+ for a SysV init script by the same name (with the
+ <filename>.service</filename> suffix removed) and
+ dynamically creates a service unit from that
+ script. This is useful for compatibility with
+ SysV.</para>
</refsect1>
<refsect1>
<title>Options</title>
+ <para>Service files must include a
+ <literal>[Service]</literal> section, which carries
+ information about the service and the process it
+ supervises. A number of options that may be used in
+ this section are shared with other unit types. These
+ options are documented in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
+ options specific to the <literal>[Service]</literal>
+ section of service units are the following:</para>
+
<variablelist>
<varlistentry>
<term><varname>Type=</varname></term>
- <listitem>
- <para>One of
- <literal>forking</literal>,
- <literal>simple</literal>,
- <literal>finish</literal>,
- <literal>dbus</literal>.</para>
-
- <para>If set to
- <literal>forking</literal>
- (the default) it is expected
- that the process configured
- with
- <varname>ExecStart=</varname>
- will start up and call
- <function>fork()</function>. The
- parent process is expected to
- finish when start-up is
- complete and all communication
- channels set up. The child
- continues to run as the main
- daemon process. This is the
- behaviour of traditional UNIX
- daemons. If this setting is
- used, it is recommended to also
- use the
- <varname>PIDFile=</varname>
- option, so that systemd can
- identify the main process of
- the daemon. systemd will proceed
- starting follow-up units as soon
- as the parent process exits.</para>
-
- <para>If set to
- <literal>simple</literal> (the
- recommended value) it is
- expected that the process
- configured with
- <varname>ExecStart=</varname>
- is the main process of the
- daemon. In this mode,
- communication channels must be
- available before the daemon is
- started up (sockets set up by systemd),
- as systemd will immediately proceed
- starting follow-up units.</para>
-
- <para>Behaviour of
- <literal>finish</literal> is
- similar to
- <literal>simple</literal>,
- however it is expected that
- the process has to exit before
- systemd starts follow-up
- units. <varname>ValidNoProcess=</varname>
- is particularly useful for
- this type of service.</para>
-
- <para>Behaviour of
- <literal>dbus</literal> is
- similar to
- <literal>simple</literal>,
- however it is expected that
- the daemon acquires a name on
- the D-Bus bus, as configured
- by
- <varname>BusName=</varname>. Systemd will
- proceed starting follow-up
- units after the D-Bus bus name has been
- acquired.</para>
+
+ <listitem><para>Configures the process
+ start-up type for this service
+ unit. One of <option>simple</option>,
+ <option>forking</option>,
+ <option>oneshot</option>,
+ <option>dbus</option>,
+ <option>notify</option>.</para>
+
+ <para>If set to
+ <option>simple</option> (the default
+ value) it is expected that the process
+ configured with
+ <varname>ExecStart=</varname> is the
+ main process of the service. In this
+ mode, if the process offers
+ functionality to other processes on
+ the system its communication channels
+ should be installed before the daemon
+ is started up (e.g. sockets set up by
+ systemd, via socket activation), as
+ systemd will immediately proceed
+ starting follow-up units.</para>
+
+ <para>If set to
+ <option>forking</option> it is
+ expected that the process configured
+ with <varname>ExecStart=</varname>
+ will call <function>fork()</function>
+ as part of its start-up. The parent process is
+ expected to exit when start-up is
+ complete and all communication
+ channels set up. The child continues
+ to run as the main daemon
+ process. This is the behaviour of
+ traditional UNIX daemons. If this
+ setting is used, it is recommended to
+ also use the
+ <varname>PIDFile=</varname> option, so
+ that systemd can identify the main
+ process of the daemon. systemd will
+ proceed starting follow-up units as
+ soon as the parent process
+ exits.</para>
+
+ <para>Behaviour of
+ <option>oneshot</option> is similar
+ to <option>simple</option>, however
+ it is expected that the process has to
+ exit before systemd starts follow-up
+ units. <varname>RemainAfterExit=</varname>
+ is particularly useful for this type
+ of service.</para>
+
+ <para>Behaviour of
+ <option>dbus</option> is similar to
+ <option>simple</option>, however it is
+ expected that the daemon acquires a
+ name on the D-Bus bus, as configured
+ by
+ <varname>BusName=</varname>. systemd
+ will proceed starting follow-up units
+ after the D-Bus bus name has been
+ acquired. Service units with this
+ option configured implicitly gain
+ dependencies on the
+ <filename>dbus.target</filename>
+ unit.</para>
+
+ <para>Behaviour of
+ <option>notify</option> is similar to
+ <option>simple</option>, however it is
+ expected that the daemon sends a
+ notification message via
+ <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ or an equivalent call when it finished
+ starting up. systemd will proceed
+ starting follow-up units after this
+ notification message has been sent. If
+ this option is used
+ <varname>NotifyAccess=</varname> (see
+ below) should be set to open access to
+ the notification socket provided by
+ systemd. If
+ <varname>NotifyAccess=</varname> is not
+ set, it will implicitly be set to
+ <option>main</option>.</para>
</listitem>
</varlistentry>
+
<varlistentry>
- <term><varname>ValidNoProcess=</varname></term>
- <listitem>
-
<para>Takes a boolean value
- that specifies whether the service
- shall be considered active
- even when all its processes
- exited. Defaults to <literal>no</literal>.</para>
+ <term><varname>RemainAfterExit=</varname></term>
+
+
<listitem><para>Takes a boolean value
+ that specifies whether the service
+ shall be considered active even when
+ all its processes exited. Defaults to
+ <option>no</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>PIDFile=</varname></term>
- <listitem>
- <para>Takes an absolute file
- name pointing to the PID file
- of this daemon. Use of this
- option is recommended for
- services where
- <varname>Type=</varname> is
- set to
- <literal>forking</literal>.</para>
+
+ <listitem><para>Takes an absolute file
+ name pointing to the PID file of this
+ daemon. Use of this option is
+ recommended for services where
+ <varname>Type=</varname> is set to
+ <option>forking</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>BusName=</varname></term>
- <listitem>
- <para>Takes a D-Bus bus name,
- where this service is reachable
- as. This option is mandatory
- for services where
- <varname>Type=</varname> is
- set to
- <literal>dbus</literal>, but
- its use is otherwise
- recommended as well if the
- process takes a name on the
- D-Bus bus.</para>
+
+ <listitem><para>Takes a D-Bus bus
+ name, where this service is reachable
+ as. This option is mandatory for
+ services where
+ <varname>Type=</varname> is set to
+ <option>dbus</option>, but its use
+ is otherwise recommended as well if
+ the process takes a name on the D-Bus
+ bus.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>ExecStart=</varname></term>
- <listitem>
- <para>Takes a command line
- that is executed when this
- service shall be started
- up. The first word of the
- command line must be an
- absolute file name. It is
- mandatory to set this option
- for all services.</para>
- </listitem>
+ <listitem><para>Takes a command line
+ that is executed when this service
+ shall be started up. The first token
+ of the command line must be an
+ absolute file name, then followed by
+ arguments for the process. It is
+ mandatory to set this option for all
+ services. This option may not be
+ specified more than once, except when
+ <varname>Type=oneshot</varname> is
+ used in which case more than one
+ <varname>ExecStart=</varname> line is
+ accepted which are then invoked one by
+ one, sequentially in the order they
+ appear in the unit file.</para>
+
+ <para>Optionally, if the absolute file
+ name is prefixed with
+ <literal>@</literal>, the second token
+ will be passed as
+ <literal>argv[0]</literal> to the
+ executed process, followed by the
+ further arguments specified. If the
+ first token is prefixed with
+ <literal>-</literal> an exit code of
+ the command normally considered a
+ failure (i.e. non-zero exit status or
+ abnormal exit due to signal) is ignored
+ and considered success. If both
+ <literal>-</literal> and
+ <literal>@</literal> are used for the
+ same command the former must precede
+ the latter. Unless
+ <varname>Type=forking</varname> is
+ set, the process started via this
+ command line will be considered the
+ main process of the daemon. The
+ command line accepts % specifiers as
+ described in
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. On
+ top of that basic environment variable
+ substitution is supported, where
+ <literal>${FOO}</literal> is replaced
+ by the string value of the environment
+ variable of the same name. Also
+ <literal>$FOO</literal> may appear as
+ separate word on the command line in
+ which case the variable is replaced by
+ its value split at whitespaces. Note
+ that the first argument (i.e. the
+ binary to execute) may not be a
+ variable, and must be a literal and
+ absolute path name.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ExecStartPre=</varname></term>
+ <term><varname>ExecStartPost=</varname></term>
+ <listitem><para>Additional commands
+ that are executed before (resp. after)
+ the command in
+ <varname>ExecStart=</varname>. Multiple
+ command lines may be concatenated in a
+ single directive, by separating them
+ by semicolons (these semicolons must
+ be passed as separate words). In that
+ case, the commands are executed one
+ after the other,
+ serially. Alternatively, these
+ directives may be specified more than
+ once with the same effect. However,
+ the latter syntax is not recommended
+ for compatibility with parsers
+ suitable for XDG
+ <filename>.desktop</filename> files.
+ Use of these settings is
+ optional. Specifier and environment
+ variable substitution is
+ supported.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ExecReload=</varname></term>
+ <listitem><para>Commands to execute to
+ trigger a configuration reload in the
+ service. This argument takes multiple
+ command lines, following the same
+ scheme as pointed out for
+ <varname>ExecStartPre=</varname>
+ above. Use of this setting is
+ optional. Specifier and environment
+ variable substitution is supported
+ here following the same scheme as for
+ <varname>ExecStart=</varname>. One
+ special environment variable is set:
+ if known <literal>$MAINPID</literal> is
+ set to the main process of the
+ daemon, and may be used for command
+ lines like the following:
+ <command>/bin/kill -HUP
+ $MAINPID</command>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ExecStop=</varname></term>
+ <listitem><para>Commands to execute to
+ stop the service started via
+ <varname>ExecStart=</varname>. This
+ argument takes multiple command lines,
+ following the same scheme as pointed
+ out for
+ <varname>ExecStartPre=</varname>
+ above. Use of this setting is
+ optional. All processes remaining for
+ a service after the commands
+ configured in this option are run are
+ terminated according to the
+ <varname>KillMode=</varname> setting
+ (see below). If this option is not
+ specified the process is terminated
+ right-away when service stop is
+ requested. Specifier and environment
+ variable substitution is supported
+ (including
+ <literal>$MAINPID</literal>, see
+ above).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ExecStopPost=</varname></term>
+ <listitem><para>Additional commands
+ that are executed after the service
+ was stopped using the commands
+ configured in
+ <varname>ExecStop=</varname>. This
+ argument takes multiple command lines,
+ following the same scheme as pointed
+ out for
+ <varname>ExecStartPre</varname>. Use
+ of these settings is
+ optional. Specifier and environment
+ variable substitution is
+ supported.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RestartSec=</varname></term>
+ <listitem><para>Configures the time to
+ sleep before restarting a service (as
+ configured with
+ <varname>Restart=</varname>). Takes a
+ unit-less value in seconds, or a time
+ span value such as "5min
+ 20s". Defaults to
+ 100ms.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>TimeoutSec=</varname></term>
+ <listitem><para>Configures the time to
+ wait for start-up and stop. If a
+ daemon service does not signal
+ start-up completion within the
+ configured time the service will be
+ considered failed and be shut down
+ again. If a service is asked to stop
+ but does not terminate in the
+ specified time it will be terminated
+ forcibly via SIGTERM, and after
+ another delay of this time with
+ SIGKILL. (See
+ <varname>KillMode=</varname>
+ below.) Takes a unit-less value in seconds, or a
+ time span value such as "5min
+ 20s". Pass 0 to disable the timeout
+ logic. Defaults to
+ 60s.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Restart=</varname></term>
+ <listitem><para>Configures whether the
+ main service process shall be
+ restarted when it exits. Takes one of
+ <option>no</option>,
+ <option>on-success</option>,
+ <option>on-failure</option>,
+ <option>on-abort</option> or
+ <option>always</option>. If set to
+ <option>no</option> (the default) the
+ service will not be restarted when it
+ exits. If set to
+ <option>on-success</option> it will be
+ restarted only when it exited cleanly,
+ i.e. terminated with an exit code of
+ 0. If set to
+ <option>on-failure</option> it will be
+ restarted only when it exited with an
+ exit code not equalling 0, or when
+ terminated by a signal. If set to
+ <option>on-abort</option> it will be
+ restarted only if it exits due to
+ reception of an uncaught signal. If
+ set to <option>always</option> the
+ service will be restarted regardless
+ whether it exited cleanly or not, or
+ got terminated abnormally by a
+ signal.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PermissionsStartOnly=</varname></term>
+ <listitem><para>Takes a boolean
+ argument. If true, the permission
+ related execution options as
+ configured with
+ <varname>User=</varname> and similar
+ options (see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for more information) are only applied
+ to the process started with
+ <varname>ExecStart=</varname>, and not
+ to the various other
+ <varname>ExecStartPre=</varname>,
+ <varname>ExecStartPost=</varname>,
+ <varname>ExecReload=</varname>,
+ <varname>ExecStop=</varname>,
+ <varname>ExecStopPost=</varname>
+ commands. If false, the setting is
+ applied to all configured commands the
+ same way. Defaults to
+ false.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RootDirectoryStartOnly=</varname></term>
+ <listitem><para>Takes a boolean
+ argument. If true, the root directory
+ as configured with the
+ <varname>RootDirectory=</varname>
+ option (see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for more information) is only applied
+ to the process started with
+ <varname>ExecStart=</varname>, and not
+ to the various other
+ <varname>ExecStartPre=</varname>,
+ <varname>ExecStartPost=</varname>,
+ <varname>ExecReload=</varname>,
+ <varname>ExecStop=</varname>,
+ <varname>ExecStopPost=</varname>
+ commands. If false, the setting is
+ applied to all configured commands the
+ same way. Defaults to
+ false.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SysVStartPriority=</varname></term>
+ <listitem><para>Set the SysV start
+ priority to use to order this service
+ in relation to SysV services lacking
+ LSB headers. This option is only
+ necessary to fix ordering in relation
+ to legacy SysV services, that have no
+ ordering information encoded in the
+ script headers. As such it should only
+ be used as temporary compatibility
+ option, and not be used in new unit
+ files. Almost always it is a better
+ choice to add explicit ordering
+ directives via
+ <varname>After=</varname> or
+ <varname>Before=</varname>,
+ instead. For more details see
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
+ used, pass an integer value in the
+ range 0-99.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>KillMode=</varname></term>
+ <listitem><para>Specifies how
+ processes of this service shall be
+ killed. One of
+ <option>control-group</option>,
+ <option>process-group</option>,
+ <option>process</option>,
+ <option>none</option>.</para>
+
+ <para>If set to
+ <option>control-group</option> all
+ remaining processes in the control
+ group of this service will be
+ terminated on service stop, after the
+ stop command (as configured with
+ <varname>ExecStop=</varname>) is
+ executed. If set to
+ <option>process-group</option> only
+ the members of the process group of
+ the main service process are
+ killed. If set to
+ <option>process</option> only the main
+ process itself is killed. If set to
+ <option>none</option> no process is
+ killed. In this case only the stop
+ command will be executed on service
+ stop, but no process be killed
+ otherwise. Processes remaining alive
+ after stop are left in their control
+ group and the control group continues
+ to exist after stop unless it is
+ empty. Defaults to
+ <option>control-group</option>.</para>
+
+ <para>Processes will first be
+ terminated via SIGTERM. If then after
+ a delay (configured via the
+ <varname>TimeoutSec=</varname> option)
+ processes still remain, the
+ termination request is repeated with
+ the SIGKILL signal. See
+ <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for more
+ information.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>NonBlocking=</varname></term>
+ <listitem><para>Set O_NONBLOCK flag
+ for all file descriptors passed via
+ socket-based activation. If true, all
+ file descriptors >= 3 (i.e. all except
+ STDIN/STDOUT/STDERR) will have
+ the O_NONBLOCK flag set and hence are in
+ non-blocking mode. This option is only
+ useful in conjunction with a socket
+ unit, as described in
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
+ to false.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>NotifyAccess=</varname></term>
+ <listitem><para>Controls access to the
+ service status notification socket, as
+ accessible via the
+ <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ call. Takes one of
+ <option>none</option> (the default),
+ <option>main</option> or
+ <option>all</option>. If
+ <option>none</option> no daemon status
+ updates are accepted from the service
+ processes, all status update messages
+ are ignored. If <option>main</option>
+ only service updates sent from the
+ main process of the service are
+ accepted. If <option>all</option> all
+ services updates from all members of
+ the service's control group are
+ accepted. This option must be set to
+ open access to the notification socket
+ when using
+ <varname>Type=notify</varname> (see above).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Sockets=</varname></term>
+ <listitem><para>Specifies the name of
+ the socket units this service shall
+ inherit the sockets from when the
+ service (ignoring the different suffix
+ of course) is started. Normally it
+ should not be necessary to use this
+ setting as all sockets whose unit
+ shares the same name as the service
+ are passed to the spawned
+ process.</para>
+
+ <para>Note that the same socket may be
+ passed to multiple processes at the
+ same time. Also note that a different
+ service may be activated on incoming
+ traffic than inherits the sockets. Or
+ in other words: The
+ <varname>Service=</varname> setting of
+ <filename>.socket</filename> units
+ doesn't have to match the inverse of the
+ <varname>Sockets=</varname> setting of
+ the <filename>.service</filename> it
+ refers to.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>FsckPassNo=</varname></term>
+ <listitem><para>Set the fsck passno
+ priority to use to order this service
+ in relation to other file system
+ checking services. This option is only
+ necessary to fix ordering in relation
+ to fsck jobs automatically created for
+ all <filename>/etc/fstab</filename>
+ entries with a value in the fs_passno
+ column > 0. As such it should only be
+ used as option for fsck
+ services. Almost always it is a better
+ choice to add explicit ordering
+ directives via
+ <varname>After=</varname> or
+ <varname>Before=</varname>,
+ instead. For more details see
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
+ used, pass an integer value in the
+ same range as
+ <filename>/etc/fstab</filename>'s
+ fs_passno column. See
+ <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details.</para></listitem>
</varlistentry>
</variablelist>
<refsect1>
<title>See Also</title>
<para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff