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 convencience 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.

       --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_COLORS
           The value must be a boolean. Controls whether colorized output
           should be generated. This can be specified to override the
           decision that systemd makes 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 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-09-18.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

systemd 246                                                   PORTABLECTL(1)

Pages that refer to this page: 30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)systemd-portabled(8)systemd-portabled.service(8)