systemd.path

SYSTEMD.PATH(5)                   systemd.path                   SYSTEMD.PATH(5)



NAME
       systemd.path - Path unit configuration

SYNOPSIS
       path.path

DESCRIPTION
       A unit configuration file whose name ends in ".path" encodes information
       about a path monitored by systemd, for path-based activation.

       This man page lists the configuration options specific to this unit type.
       See systemd.unit(5) for the common options of all unit configuration
       files. The common configuration items are configured in the generic
       [Unit] and [Install] sections. The path specific configuration options
       are configured in the [Path] section.

       For each path file, a matching unit file must exist, describing the unit
       to activate when the path changes. By default, a service by the same name
       as the path (except for the suffix) is activated. Example: a path file
       foo.path activates a matching service foo.service. The unit to activate
       may be controlled by Unit= (see below).

       Internally, path units use the inotify(7) API to monitor file systems.
       Due to that, it suffers by the same limitations as inotify, and for
       example cannot be used to monitor files or directories changed by other
       machines on remote NFS file systems.

       When a service unit triggered by a path unit terminates (regardless
       whether it exited successfully or failed), monitored paths are checked
       immediately again, and the service accordingly restarted instantly. As
       protection against busy looping in this trigger/start cycle, a start rate
       limit is enforced on the service unit, see StartLimitIntervalSec= and
       StartLimitBurst= in systemd.unit(5). Unlike other service failures, the
       error condition that the start rate limit is hit is propagated from the
       service unit to the path unit and causes the path unit to fail as well,
       thus ending the loop.

AUTOMATIC DEPENDENCIES
   Implicit Dependencies
       The following dependencies are implicitly added:

       •   If a path unit is beneath another mount unit in the file system
           hierarchy, both a requirement and an ordering dependency between both
           units are created automatically.

       •   An implicit Before= dependency is added between a path unit and the
           unit it is supposed to activate.

   Default Dependencies
       The following dependencies are added unless DefaultDependencies=no is
       set:

       •   Path units will automatically have dependencies of type Before= on
           paths.target, dependencies of type After= and Requires= on
           sysinit.target, and have dependencies of type Conflicts= and Before=
           on shutdown.target. These ensure that path units are terminated
           cleanly prior to system shutdown. Only path units involved with early
           boot or late system shutdown should disable DefaultDependencies=
           option.

OPTIONS
       Path files must include a [Path] section, which carries information about
       the path(s) it monitors. The options specific to the [Path] section of
       path units are the following:

       PathExists=, PathExistsGlob=, PathChanged=, PathModified=,
       DirectoryNotEmpty=
           Defines paths to monitor for certain changes: PathExists= may be used
           to watch the mere existence of a file or directory. If the file
           specified exists, the configured unit is activated.  PathExistsGlob=
           works similar, but checks for the existence of at least one file
           matching the globbing pattern specified.  PathChanged= may be used to
           watch a file or directory and activate the configured unit whenever
           it changes. It is not activated on every write to the watched file
           but it is activated if the file which was open for writing gets
           closed.  PathModified= is similar, but additionally it is activated
           also on simple writes to the watched file.  DirectoryNotEmpty= may be
           used to watch a directory and activate the configured unit whenever
           it contains at least one file.

           The arguments of these directives must be absolute file system paths.

           Multiple directives may be combined, of the same and of different
           types, to watch multiple paths. If the empty string is assigned to
           any of these options, the list of paths to watch is reset, and any
           prior assignments of these options will not have any effect.

           If a path already exists (in case of PathExists= and PathExistsGlob=)
           or a directory already is not empty (in case of DirectoryNotEmpty=)
           at the time the path unit is activated, then the configured unit is
           immediately activated as well. Something similar does not apply to
           PathChanged= and PathModified=.

           If the path itself or any of the containing directories are not
           accessible, systemd will watch for permission changes and notice that
           conditions are satisfied when permissions allow that.

       Unit=
           The unit to activate when any of the configured paths changes. The
           argument is a unit name, whose suffix is not ".path". If not
           specified, this value defaults to a service that has the same name as
           the path unit, except for the suffix. (See above.) It is recommended
           that the unit name that is activated and the unit name of the path
           unit are named identical, except for the suffix.

       MakeDirectory=
           Takes a boolean argument. If true, the directories to watch are
           created before watching. This option is ignored for PathExists=
           settings. Defaults to false.

       DirectoryMode=
           If MakeDirectory= is enabled, use the mode specified here to create
           the directories in question. Takes an access mode in octal notation.
           Defaults to 0755.

SEE ALSO
       systemd(1), systemctl(1), systemd.unit(5), systemd.service(5),
       inotify(7), systemd.directives(7)



systemd 247                                                      SYSTEMD.PATH(5)