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NAME | SYNOPSIS | DESCRIPTION | COMMANDS | OPTIONS | FILES AND DIRECTORIES | PROFILES | EXIT STATUS | ENVIRONMENT | SEE ALSO | COLOPHON |
PORTABLECTL(1) portablectl PORTABLECTL(1)
portablectl - Attach, detach or inspect portable service images
portablectl [OPTIONS...] {COMMAND} [NAME...]
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.)
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.
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.
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.
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.
On success, 0 is returned, a non-zero failure code otherwise.
$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.
systemd(1), systemd-portabled.service(8)
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 2020-08-13. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-08-11.) 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)