portablectl(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMANDS | OPTIONS | FILES AND DIRECTORIES | PROFILES | EXIT STATUS | ENVIRONMENT | SEE ALSO | COLOPHON

PORTABLECTL(1)                 portablectl                PORTABLECTL(1)

NAME         top

       portablectl - Attach, detach or inspect portable service images

SYNOPSIS         top

       portablectl [OPTIONS...] {COMMAND} [NAME...]

DESCRIPTION         top

       portablectl may be used to attach, detach or inspect portable
       service images. It's primarily a command interfacing with
       systemd-portabled.service(8).

       Portable service images contain an OS file system tree along with
       systemd(1) unit file information. A service image may be
       "attached" to the local system. If attached, a set of unit files
       are copied from the image to the host, and extended with
       RootDirectory= or RootImage= assignments (in case of service
       units) pointing to the image file or directory, ensuring the
       services will run within the file system context of the image.

       Portable service images are an efficient way to bundle multiple
       related services and other units together, and transfer them as a
       whole between systems. When these images are attached the local
       system the contained units may run in most ways like regular
       system-provided units, either with full privileges or inside
       strict sandboxing, depending on the selected configuration.

       Specifically portable service images may be of the following
       kind:

       •   Directory trees containing an OS, including the top-level
           directories /usr/, /etc/, and so on.

       •   btrfs subvolumes containing OS trees, similar to normal
           directory trees.

       •   Binary "raw" disk images containing MBR or GPT partition
           tables and Linux file system partitions. (These must be
           regular files, with the .raw suffix.)

COMMANDS         top

       The following commands are understood:

       list
           List available portable service images. This will list all
           portable service images discovered in the portable image
           search paths (see below), along with brief metadata and state
           information. Note that many of the commands below may both
           operate on images inside and outside of the search paths.
           This command is hence mostly a convenience option, the
           commands are generally not restricted to what this list
           shows.

       attach IMAGE [PREFIX...]
           Attach a portable service image to the host system. Expects a
           file system path to a portable service image file or
           directory as first argument. If the specified path contains
           no slash character ("/") it is understood as image filename
           that is searched for in the portable service image search
           paths (see below). To reference a file in the current working
           directory prefix the filename with "./" to avoid this search
           path logic.

           When a portable service is attached four operations are
           executed:

            1. All unit files of types .service, .socket, .target,
               .timer and .path which match the indicated unit file name
               prefix are copied from the image to the host's
               /etc/systemd/system.attached/ directory (or
               /run/systemd/system.attached/ — depending whether
               --runtime is specified, see above), which is included in
               the built-in unit search path of the system service
               manager.

            2. For unit files of type .service a drop-in is added to
               these copies that adds RootDirectory= or RootImage=
               settings (see systemd.unit(5) for details), that ensures
               these services are run within the file system of the
               originating portable service image.

            3. A second drop-in is created: the "profile" drop-in, that
               may contain additional security settings (and other
               settings). A number of profiles are available by default
               but administrators may define their own ones. See below.

            4. If the portable service image file is not already in the
               search path (see below), a symbolic link to it is created
               in /etc/portables/ or /run/portables/, to make sure it is
               included in it.

           By default all unit files whose names start with a prefix
           generated from the image's file name are copied out.
           Specifically, the prefix is determined from the image file
           name with any suffix such as .raw removed, truncated at the
           first occurrence of an underscore character ("_"), if there
           is one. The underscore logic is supposed to be used to
           versioning so that the an image file foobar_47.11.raw will
           result in a unit file matching prefix of foobar. This prefix
           is then compared with all unit files names contained in the
           image in the usual directories, but only unit file names
           where the prefix is followed by "-", "."  or "@" are
           considered. Example: if a portable service image file is
           named foobar_47.11.raw then by default all its unit files
           with names such as foobar-quux-waldi.service, foobar.service
           or foobar@.service will be considered. It's possible to
           override the matching prefix: all strings listed on the
           command line after the image file name are considered
           prefixes, overriding the implicit logic where the prefix is
           derived from the image file name.

           By default, after the unit files are attached the service
           manager's configuration is reloaded, except when --no-reload
           is specified (see above). This ensures that the new units
           made available to the service manager are seen by it.

           If --now and/or --enable are passed, the portable service(s)
           are immediately started (blocking operation unless --no-block
           is passed) and/or enabled after attaching the image.

       detach IMAGE [PREFIX...]
           Detaches a portable service image from the host. This undoes
           the operations executed by the attach command above, and
           removes the unit file copies, drop-ins and image symlink
           again. This command expects an image name or path as
           parameter. Note that if a path is specified only the last
           component of it (i.e. the file or directory name itself, not
           the path to it) is used for finding matching unit files. This
           is a convenience feature to allow all arguments passed as
           attach also to detach.

           If --now and/or --enable are passed, the portable service(s)
           are immediately stopped (blocking operation) and/or disabled
           before detaching the image. Prefix(es) are also accepted, to
           be used in case the unit names do not match the image name as
           described in the attach.

       inspect IMAGE [PREFIX...]
           Extracts various metadata from a portable service image and
           presents it to the caller. Specifically, the os-release(5)
           file of the image is retrieved as well as all matching unit
           files. By default a short summary showing the most relevant
           metadata in combination with a list of matching unit files is
           shown (that is the unit files attach would install to the
           host system). If combined with --cat (see above), the
           os-release data and the units files' contents is displayed
           unprocessed. This command is useful to determine whether an
           image qualifies as portable service image, and which unit
           files are included. This command expects the path to the
           image as parameter, optionally followed by a list of unit
           file prefixes to consider, similar to the attach command
           described above.

       is-attached IMAGE
           Determines whether the specified image is currently attached
           or not. Unless combined with the --quiet switch this will
           show a short state identifier for the image. Specifically:

           Table 1. Image attachment states
           ┌─────────────────┬──────────────────────────┐
           │State            Description              │
           ├─────────────────┼──────────────────────────┤
           │detached         │ The image is currently   │
           │                 │ not attached.            │
           ├─────────────────┼──────────────────────────┤
           │attached         │ The image is currently   │
           │                 │ attached, i.e. its unit  │
           │                 │ files have been made     │
           │                 │ available to the host    │
           │                 │ system.                  │
           ├─────────────────┼──────────────────────────┤
           │attached-runtime │ Like attached, but the   │
           │                 │ unit files have been     │
           │                 │ made available           │
           │                 │ transiently only, i.e.   │
           │                 │ the attach command has   │
           │                 │ been invoked with the    │
           │                 │ --runtime option.        │
           ├─────────────────┼──────────────────────────┤
           │enabled          │ The image is currently   │
           │                 │ attached, and at least   │
           │                 │ one unit file associated │
           │                 │ with it has been         │
           │                 │ enabled.                 │
           ├─────────────────┼──────────────────────────┤
           │enabled-runtime  │ Like enabled, but the    │
           │                 │ unit files have been     │
           │                 │ made available           │
           │                 │ transiently only, i.e.   │
           │                 │ the attach command has   │
           │                 │ been invoked with the    │
           │                 │ --runtime option.        │
           ├─────────────────┼──────────────────────────┤
           │running          │ The image is currently   │
           │                 │ attached, and at least   │
           │                 │ one unit file associated │
           │                 │ with it is running.      │
           ├─────────────────┼──────────────────────────┤
           │running-runtime  │ The image is currently   │
           │                 │ attached transiently,    │
           │                 │ and at least one unit    │
           │                 │ file associated with it  │
           │                 │ is running.              │
           └─────────────────┴──────────────────────────┘

       read-only IMAGE [BOOL]
           Marks or (unmarks) a portable service image read-only. Takes
           an image name, followed by a boolean as arguments. If the
           boolean is omitted, positive is implied, i.e. the image is
           marked read-only.

       remove IMAGE...
           Removes one or more portable service images. Note that this
           command will only remove the specified image path itself — it
           refers to a symbolic link then the symbolic link is removed
           and not the image it points to.

       set-limit [IMAGE] BYTES
           Sets the maximum size in bytes that a specific portable
           service image, or all images, may grow up to on disk (disk
           quota). Takes either one or two parameters. The first,
           optional parameter refers to a portable service image name.
           If specified, the size limit of the specified image is
           changed. If omitted, the overall size limit of the sum of all
           images stored locally is changed. The final argument
           specifies the size limit in bytes, possibly suffixed by the
           usual K, M, G, T units. If the size limit shall be disabled,
           specify "-" as size.

           Note that per-image size limits are only supported on btrfs
           file systems. Also, depending on BindPaths= settings in the
           portable service's unit files directories from the host might
           be visible in the image environment during runtime which are
           not affected by this setting, as only the image itself is
           counted against this limit.

OPTIONS         top

       The following options are understood:

       -q, --quiet
           Suppresses additional informational output while running.

       -p PROFILE, --profile=PROFILE
           When attaching an image, select the profile to use. By
           default the "default" profile is used. For details about
           profiles, see below.

       --copy=
           When attaching an image, select whether to prefer copying or
           symlinking of files installed into the host system. Takes one
           of "copy" (to prefer copying of files), "symlink" (to prefer
           creation of symbolic links) or "auto" for an intermediary
           mode where security profile drop-ins are symlinked while unit
           files are copied. Note that this option expresses a
           preference only, in cases where symbolic links cannot be
           created — for example when the image operated on is a raw
           disk image, and hence not directly referentiable from the
           host file system — copying of files is used unconditionally.

       --runtime
           When specified the unit and drop-in files are placed in
           /run/systemd/system.attached/ instead of
           /etc/systemd/system.attached/. Images attached with this
           option set hence remain attached only until the next reboot,
           while they are normally attached persistently.

       --no-reload
           Don't reload the service manager after attaching or detaching
           a portable service image. Normally the service manager is
           reloaded to ensure it is aware of added or removed unit
           files.

       --cat
           When inspecting portable service images, show the
           (unprocessed) contents of the metadata files pulled from the
           image, instead of brief summaries. Specifically, this will
           show the os-release(5) and unit file contents of the image.

       --enable
           Immediately enable/disable the portable service after
           attaching/detaching.

       --now
           Immediately start/stop the portable service after
           attaching/before detaching.

       --no-block
           Don't block waiting for attach --now to complete.

       -H, --host=
           Execute the operation remotely. Specify a hostname, or a
           username and hostname separated by "@", to connect to. The
           hostname may optionally be suffixed by a port ssh is
           listening on, separated by ":", and then a container name,
           separated by "/", which connects directly to a specific
           container on the specified host. This will use SSH to talk to
           the remote machine manager instance. Container names may be
           enumerated with machinectl -H HOST. Put IPv6 addresses in
           brackets.

       -M, --machine=
           Execute operation on a local container. Specify a container
           name to connect to, optionally prefixed by a user name to
           connect as and a separating "@" character. If the special
           string ".host" is used in place of the container name, a
           connection to the local system is made (which is useful to
           connect to a specific user's user bus: "--user
           --machine=lennart@.host"). If the "@" syntax is not used, the
           connection is made as root user. If the "@" syntax is used
           either the left hand side or the right hand side may be
           omitted (but not both) in which case the local user name and
           ".host" are implied.

       --no-pager
           Do not pipe output into a pager.

       --no-legend
           Do not print the legend, i.e. column headers and the footer
           with hints.

       --no-ask-password
           Do not query the user for authentication for privileged
           operations.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

FILES AND DIRECTORIES         top

       Portable service images are preferably stored in
       /var/lib/portables/, but are also searched for in
       /etc/portables/, /run/systemd/portables/,
       /usr/local/lib/portables/ and /usr/lib/portables/. It's
       recommended not to place image files directly in /etc/portables/
       or /run/systemd/portables/ (as these are generally not suitable
       for storing large or non-textual data), but use these directories
       only for linking images located elsewhere into the image search
       path.

       When a portable service image is attached, matching unit files
       are copied onto the host into the /etc/systemd/system.attached/
       and /run/systemd/system.attached/ directories. When an image is
       detached, the unit files are removed again from these
       directories.

PROFILES         top

       When portable service images are attached a "profile" drop-in is
       linked in, which may be used to enforce additional security (and
       other) restrictions locally. Four profile drop-ins are defined by
       default, and shipped in /usr/lib/systemd/portable/profile/.
       Additional, local profiles may be defined by placing them in
       /etc/systemd/portable/profile/. The default profiles are:

       Table 2. Profiles
       ┌──────────┬──────────────────────────┐
       │Name      Description              │
       ├──────────┼──────────────────────────┤
       │default   │ This is the default      │
       │          │ profile if no other      │
       │          │ profile name is set via  │
       │          │ the --profile= (see      │
       │          │ above). It's fairly      │
       │          │ restrictive, but should  │
       │          │ be useful for common,    │
       │          │ unprivileged system      │
       │          │ workloads. This includes │
       │          │ write access to the      │
       │          │ logging framework, as    │
       │          │ well as IPC access to    │
       │          │ the D-Bus system.        │
       ├──────────┼──────────────────────────┤
       │nonetwork │ Very similar to default, │
       │          │ but networking is turned │
       │          │ off for any services of  │
       │          │ the portable service     │
       │          │ image.                   │
       ├──────────┼──────────────────────────┤
       │strict    │ A profile with very      │
       │          │ strict settings. This    │
       │          │ profile excludes IPC     │
       │          │ (D-Bus) and network      │
       │          │ access.                  │
       ├──────────┼──────────────────────────┤
       │trusted   │ A profile with very      │
       │          │ relaxed settings. In     │
       │          │ this profile the         │
       │          │ services run with full   │
       │          │ privileges.              │
       └──────────┴──────────────────────────┘

       For details on these profiles and their effects see their precise
       definitions, e.g.
       /usr/lib/systemd/portable/profile/default/service.conf and
       similar.

EXIT STATUS         top

       On success, 0 is returned, a non-zero failure code otherwise.

ENVIRONMENT         top

       $SYSTEMD_PAGER
           Pager to use when --no-pager is not given; overrides $PAGER.
           If neither $SYSTEMD_PAGER nor $PAGER are set, a set of
           well-known pager implementations are tried in turn, including
           less(1) and more(1), until one is found. If no pager
           implementation is discovered no pager is invoked. Setting
           this environment variable to an empty string or the value
           "cat" is equivalent to passing --no-pager.

       $SYSTEMD_LESS
           Override the options passed to less (by default "FRSXMK").

           Users might want to change two options in particular:

           K
               This option instructs the pager to exit immediately when
               Ctrl+C is pressed. To allow less to handle Ctrl+C itself
               to switch back to the pager command prompt, unset this
               option.

               If the value of $SYSTEMD_LESS does not include "K", and
               the pager that is invoked is less, Ctrl+C will be ignored
               by the executable, and needs to be handled by the pager.

           X
               This option instructs the pager to not send termcap
               initialization and deinitialization strings to the
               terminal. It is set by default to allow command output to
               remain visible in the terminal even after the pager
               exits. Nevertheless, this prevents some pager
               functionality from working, in particular paged output
               cannot be scrolled with the mouse.

           See less(1) for more discussion.

       $SYSTEMD_LESSCHARSET
           Override the charset passed to less (by default "utf-8", if
           the invoking terminal is determined to be UTF-8 compatible).

       $SYSTEMD_PAGERSECURE
           Takes a boolean argument. When true, the "secure" mode of the
           pager is enabled; if false, disabled. If $SYSTEMD_PAGERSECURE
           is not set at all, secure mode is enabled if the effective
           UID is not the same as the owner of the login session, see
           geteuid(2) and sd_pid_get_owner_uid(3). In secure mode,
           LESSSECURE=1 will be set when invoking the pager, and the
           pager shall disable commands that open or create new files or
           start new subprocesses. When $SYSTEMD_PAGERSECURE is not set
           at all, pagers which are not known to implement secure mode
           will not be used. (Currently only less(1) implements secure
           mode.)

           Note: when commands are invoked with elevated privileges, for
           example under sudo(8) or pkexec(1), care must be taken to
           ensure that unintended interactive features are not enabled.
           "Secure" mode for the pager may be enabled automatically as
           describe above. Setting SYSTEMD_PAGERSECURE=0 or not removing
           it from the inherited environment allows the user to invoke
           arbitrary commands. Note that if the $SYSTEMD_PAGER or $PAGER
           variables are to be honoured, $SYSTEMD_PAGERSECURE must be
           set too. It might be reasonable to completely disable the
           pager using --no-pager instead.

       $SYSTEMD_COLORS
           Takes a boolean argument. When true, systemd and related
           utilities will use colors in their output, otherwise the
           output will be monochrome. Additionally, the variable can
           take one of the following special values: "16", "256" to
           restrict the use of colors to the base 16 or 256 ANSI colors,
           respectively. This can be specified to override the automatic
           decision based on $TERM and what the console is connected to.

       $SYSTEMD_URLIFY
           The value must be a boolean. Controls whether clickable links
           should be generated in the output for terminal emulators
           supporting this. This can be specified to override the
           decision that systemd makes based on $TERM and other
           conditions.

SEE ALSO         top

       systemd(1), systemd-portabled.service(8)

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-12-18.  (At that
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       (which is not part of the original manual page), send a mail to
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systemd 247                                               PORTABLECTL(1)

Pages that refer to this page: systemd.directives(7)systemd.index(7)systemd-portabled.service(8)