PORTABLECTL(1) portablectl PORTABLECTL(1)
NAME
portablectl - Attach, detach or inspect portable service images
SYNOPSIS
portablectl [OPTIONS...] {COMMAND} [NAME...]
DESCRIPTION
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 to 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. For more details, see Portable Services[1].
Portable service images may be of the following kinds:
• 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
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.
Added in version 239.
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 below), 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
below). 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 services are
immediately started (blocking operation unless --no-block is passed)
and/or enabled after attaching the image.
In place of the image path a ".v/" versioned directory may be
specified, see systemd.v(7) for details.
In place of the directory path a ".v/" versioned directory may be
specified, see systemd.v(7) for details.
Added in version 239.
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 services 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.
Added in version 239.
reattach IMAGE [PREFIX...]
Detaches an existing portable service image from the host, and
immediately attaches it again. This is useful in case the image was
replaced. Running units are not stopped during the process. Partial
matching, to allow for different versions in the image name, is
allowed: only the part before the first "_" character has to match.
If the new image does not exist, the existing one will not be
detached. The parameters follow the same syntax as the attach
command.
If --now and/or --enable are passed, the portable services are
immediately stopped if removed, started and/or enabled if added, or
restarted if updated. Prefixes are also accepted, in the same way as
described in the attach case.
Added in version 248.
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.
Added in version 239.
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. │
└──────────────────┴────────────────────────────┘
Added in version 239.
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.
Added in version 239.
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.
Added in version 239.
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.
Added in version 239.
OPTIONS
The following options are understood:
-q, --quiet
Suppresses additional informational output while running.
Added in version 239.
-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.
Added in version 239.
--copy=
When attaching an image, select whether to prefer copying or
symlinking of files installed into the host system. Takes one of
"copy" (files will be copied), "symlink" (to prefer creation of
symbolic links), "auto" for an intermediary mode where security
profile drop-ins and images are symlinked while unit files are
copied, or "mixed" (since v256) where security profile drop-ins are
symlinked while unit files and images 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.
Added in version 239.
--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.
Added in version 239.
--no-reload
Do not 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.
Added in version 239.
--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.
Added in version 239.
--enable
Immediately enable/disable the portable service after
attaching/detaching.
Added in version 245.
--now
Immediately start/stop/restart the portable service after
attaching/before detaching/after upgrading.
Added in version 245.
--no-block
Do not block waiting for attach --now to complete.
Added in version 245.
--clean
When detaching ensure the configuration, state, logs, cache, and
runtime data directories of the portable service are removed from
the host system.
Added in version 256.
--extension=PATH
Add an additional image PATH as an overlay on top of IMAGE when
attaching/detaching. This argument can be specified multiple times,
in which case the order in which images are laid down follows the
rules specified in systemd.exec(5) for the ExtensionImages=
directive and for the systemd-sysext(8) and systemd-confext(8)
tools. The images must contain an extension-release file with
metadata that matches what is defined in the os-release of IMAGE.
See: os-release(5). Images can be block images, btrfs subvolumes or
directories. For more information on portable services with
extensions, see the "Extension Images" paragraph on Portable
Services[1].
Note that the same extensions have to be specified, in the same
order, when attaching and detaching.
In place of the image path a ".v/" versioned directory may be
specified, see systemd.v(7) for details.
In place of the directory path a ".v/" versioned directory may be
specified, see systemd.v(7) for details.
Added in version 249.
--force
Skip safety checks and attach or detach images (with extensions)
without first ensuring that the units are not running, and do not
insist that the extension-release.NAME file in the extension image
has to match the image filename.
Added in version 252.
-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
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
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
On success, 0 is returned, a non-zero failure code otherwise.
ENVIRONMENT
$SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a higher
log level, i.e. less important ones, will be suppressed). Takes a
comma-separated list of values. A value may be either one of (in
order of decreasing importance) emerg, alert, crit, err, warning,
notice, info, debug, or an integer in the range 0...7. See syslog(3)
for more information. Each value may optionally be prefixed with one
of console, syslog, kmsg or journal followed by a colon to set the
maximum log level for that specific log target (e.g.
SYSTEMD_LOG_LEVEL=debug,console:info specifies to log at debug level
except when logging to the console which should be at info level).
Note that the global maximum log level takes priority over any per
target maximum log levels.
$SYSTEMD_LOG_COLOR
A boolean. If true, messages written to the tty will be colored
according to priority.
This setting is only useful when messages are written directly to
the terminal, because journalctl(1) and other tools that display
logs will color messages based on the log level on their own.
$SYSTEMD_LOG_TIME
A boolean. If true, console log messages will be prefixed with a
timestamp.
This setting is only useful when messages are written directly to
the terminal or a file, because journalctl(1) and other tools that
display logs will attach timestamps based on the entry metadata on
their own.
$SYSTEMD_LOG_LOCATION
A boolean. If true, messages will be prefixed with a filename and
line number in the source code where the message originates.
Note that the log location is often attached as metadata to journal
entries anyway. Including it directly in the message text can
nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TID
A boolean. If true, messages will be prefixed with the current
numerical thread ID (TID).
Note that the this information is attached as metadata to journal
entries anyway. Including it directly in the message text can
nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TARGET
The destination for log messages. One of console (log to the
attached tty), console-prefixed (log to the attached tty but with
prefixes encoding the log level and "facility", see syslog(3), kmsg
(log to the kernel circular log buffer), journal (log to the
journal), journal-or-kmsg (log to the journal if available, and to
kmsg otherwise), auto (determine the appropriate log target
automatically, the default), null (disable log output).
$SYSTEMD_LOG_RATELIMIT_KMSG
Whether to ratelimit kmsg or not. Takes a boolean. Defaults to
"true". If disabled, systemd will not ratelimit messages written to
kmsg.
$SYSTEMD_PAGER, $PAGER
Pager to use when --no-pager is not given. $SYSTEMD_PAGER is used
if set; otherwise $PAGER is used. If neither $SYSTEMD_PAGER nor
$PAGER are set, a set of well-known pager implementations is tried
in turn, including less(1) and more(1), until one is found. If no
pager implementation is discovered, no pager is invoked. Setting
those environment variables to an empty string or the value "cat" is
equivalent to passing --no-pager.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER and $PAGER
can only be used to disable the pager (with "cat" or ""), and are
otherwise ignored.
$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.
Note that setting the regular $LESS environment variable has no
effect for less invocations by systemd tools.
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).
Note that setting the regular $LESSCHARSET environment variable has
no effect for less invocations by systemd tools.
$SYSTEMD_PAGERSECURE
Common pager commands like less(1), in addition to "paging", i.e.
scrolling through the output, support opening of or writing to other
files and running arbitrary shell commands. When commands are
invoked with elevated privileges, for example under sudo(8) or
pkexec(1), the pager becomes a security boundary. Care must be taken
that only programs with strictly limited functionality are used as
pagers, and unintended interactive features like opening or creation
of new files or starting of subprocesses are not allowed. "Secure
mode" for the pager may be enabled as described below, if the pager
supports that (most pagers are not written in a way that takes this
into consideration). It is recommended to either explicitly enable
"secure mode" or to completely disable the pager using --no-pager or
PAGER=cat when allowing untrusted users to execute commands with
elevated privileges.
This option takes a boolean argument. When set to true, the "secure
mode" of the pager is enabled. In "secure mode", LESSSECURE=1 will
be set when invoking the pager, which instructs the pager to disable
commands that open or create new files or start new subprocesses.
Currently only less(1) is known to understand this variable and
implement "secure mode".
When set to false, no limitation is placed on the pager. Setting
SYSTEMD_PAGERSECURE=0 or not removing it from the inherited
environment may allow the user to invoke arbitrary commands.
When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to
automatically figure out if "secure mode" should be enabled and
whether the pager supports it. "Secure mode" is enabled if the
effective UID is not the same as the owner of the login session, see
geteuid(2) and sd_pid_get_owner_uid(3), or when running under
sudo(8) or similar tools ($SUDO_UID is set [2]). In those cases,
SYSTEMD_PAGERSECURE=1 will be set and pagers which are not known to
implement "secure mode" will not be used at all. Note that this
autodetection only covers the most common mechanisms to elevate
privileges and is intended as convenience. It is recommended to
explicitly set $SYSTEMD_PAGERSECURE or disable the pager.
Note that if the $SYSTEMD_PAGER or $PAGER variables are to be
honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must
be set too.
$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
systemd(1), systemd-sysext(8), org.freedesktop.portable1(5), systemd-
portabled.service(8), importctl(1)
NOTES
1. Portable Services
https://systemd.io/PORTABLE_SERVICES
2. It is recommended for other tools to set and check $SUDO_UID as
appropriate, treating it is a common interface.
systemd 257.9 PORTABLECTL(1)
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