| PORTABLECTL(1) | portablectl | PORTABLECTL(1) |
.SH "NAME" portablectl - Attach, detach or inspect portable service
images
.SH "SYNOPSIS"
.HP 288u
portablectl
[OPTIONS...]
{COMMAND}
[NAME...]
.SH "DESCRIPTION"
.PP portablectl may be used to attach, detach or inspect portable
service images. It's primarily a command interfacing with
systemd-portabled.service(8).
.PP 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.
.PP 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].
.PP Portable service images may be of the following kinds:
.SH "COMMANDS"
.PP The following commands are understood:
.PP 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.
.RE
.PP 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:
.sp
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 for versioning so that 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.
When images are attached, an image policy will be generated that pins the
attached image by the exact content that was found while attaching, so that
it cannot be swapped downgrading security (e.g.: removing dm-verity
protection) without a full reinstallation. For more details on policies, see
systemd.image-policy(7).
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.
.RE
.PP 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.
.RE
.PP 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.
.RE
.PP 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.
.RE
.PP 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:
.sp
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.
.RE
.PP 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.
.RE
.PP 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.
.RE
.PP 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.
.RE
.SH "OPTIONS"
.PP The following options are understood:
.PP -q, --quiet
Suppresses additional informational output while running.
Added in version 239.
.RE
.PP -p PROFILE, --profile=PROFILE
When attaching an image, select the profile to use. By default, the default
profile is used. Attaching fails if the selected profile does not exist. For
details about profiles, see below.
Added in version 239.
.RE
.PP --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.
.RE
.PP --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.
.RE
.PP --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.
.RE
.PP --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.
.RE
.PP --enable
Immediately enable/disable the portable service after
attaching/detaching.
Added in version 245.
.RE
.PP --now
Immediately start/stop/restart the portable service after attaching/before
detaching/after upgrading.
Added in version 245.
.RE
.PP --no-block
Do not block waiting for attach --now to complete.
Added in version 245.
.RE
.PP --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.
.RE
.PP --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.
.RE
.PP --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.
.RE
.PP -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.
.RE
.PP -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.
.RE
.PP --no-pager
Do not pipe output into a pager.
.RE
.PP --no-legend
Do not print the legend, i.e. column headers and the footer with hints.
.RE
.PP --no-ask-password
Do not query the user for authentication for privileged operations.
.RE
.PP -h, --help
Print a short help text and exit.
.RE
.PP --version
Print a short version string and exit.
.RE
.SH "FILES AND DIRECTORIES"
.PP Portable service images are preferably stored in /var/lib/portables/, but
are also searched for in /etc/portables/, /run/portables/,
/usr/local/lib/portables/ and /usr/lib/portables/. It's recommended not to
place image files directly in /etc/portables/ or /run/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.
.PP 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.
.SH "PROFILES"
.PP 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:
.sp
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. |
.PP For details on these profiles and their effects see their precise
definitions, e.g. /usr/lib/systemd/portable/profile/default/service.conf and
similar.
.SH "EXIT STATUS"
.PP On success, 0 is returned, a non-zero failure code otherwise.
.SH "ENVIRONMENT"
.PP $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.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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).
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $SYSTEMD_LESS
Override the options passed to less (by default FRSXMK).
Users might want to change two options in particular:
.PP 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.
.RE
.PP 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.
.RE
.sp
Note that setting the regular $LESS environment variable has no effect
for less invocations by systemd tools.
See less(1) for more discussion.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $SYSTEMD_COLORS
Takes a boolean argument, or a special value. By default (unset),
systemd and related utilities will use colors in their output if
possible. If $COLORTERM is set to truecolor or 24bit, 24-bit colors
will be enabled, 256 colors otherwise, unless $NO_COLOR or
$TERM indicates colors are disabled.
.PP true
Same as unset, except that $NO_COLOR is ignored.
.RE
.PP false
The output will be monochrome.
.RE
.PP 16, 256, 24bit
Always use the base 16 ANSI colors, 256 colors, or 24 bit color,
respectively.
.RE
.PP auto-16, auto-256, auto-24bit
Use the given quantity of colours, subject to $TERM, and what the
console is connected to.
.RE
.sp
.RE
.PP $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.
.RE
.SH "SEE ALSO"
.PP systemd(1), systemd-sysext(8),
org.freedesktop.portable1(5), systemd-portabled.service(8),
importctl(1)
NOTES
- 1.
- Portable Services
- 2.
-
It is recommended for other tools to set and check $SUDO_UID as appropriate, treating it is a common interface.
| systemd 262.2 |