Provided by: systemd-homed_256.5-2ubuntu4_amd64 
NAME
homectl, systemd-homed-firstboot.service - Create, remove, change or inspect home
directories
SYNOPSIS
homectl [OPTIONS...] {COMMAND} [NAME...]
DESCRIPTION
homectl may be used to create, remove, change or inspect a user's home directory. It's
primarily a command interfacing with systemd-homed.service(8) which manages home
directories of users.
Home directories managed by systemd-homed.service are self-contained, and thus include the
user's full metadata record in the home's data storage itself, making them easy to migrate
between machines. In particular, a home directory describes a matching user record, and
every user record managed by systemd-homed.service also implies existence and
encapsulation of a home directory. The user account and home directory become the same
concept.
The following backing storage mechanisms are supported:
• An individual LUKS2 encrypted loopback file for a user, stored in /home/*.home. At
login the file system contained in this files is mounted, after the LUKS2 encrypted
volume has been attached. The user's password is identical to the encryption
passphrase of the LUKS2 volume. Access to data without preceding user authentication
is thus not possible, even for the system administrator. This storage mechanism
provides the strongest data security and is thus recommended.
• Similar, but the LUKS2 encrypted file system is located on regular block device, such
as a USB storage stick. In this mode home directories and all data they include are
nicely migratable between machines, simply by plugging the USB stick into different
systems at different times.
• An encrypted directory using "fscrypt" on file systems that support it (at the moment
this is primarily "ext4"), located in /home/*.homedir. This mechanism also provides
encryption, but substantially weaker than LUKS2, as most file system metadata is
unprotected. Moreover it currently does not support changing user passwords once the
home directory has been created.
• A "btrfs" subvolume for each user, also located in /home/*.homedir. This provides no
encryption, but good quota support.
• A regular directory for each user, also located in /home/*.homedir. This provides no
encryption, but is a suitable fallback available on all machines, even where LUKS2,
"fscrypt" or "btrfs" support is not available.
• An individual Windows file share (CIFS) for each user.
Note that systemd-homed.service and homectl will not manage "classic" UNIX user accounts
as created with useradd(8) or similar tools. In particular, this functionality is not
suitable for managing system users (i.e. users with a UID below 1000) but is exclusive to
regular ("human") users.
Note that users/home directories managed via systemd-homed.service do not show up in
/etc/passwd and similar files, they are synthesized via glibc NSS during runtime. They are
thus resolvable and may be enumerated via the getent(1) tool.
This tool interfaces directly with systemd-homed.service, and may execute specific
commands on the home directories it manages. Since every home directory managed that way
also defines a JSON user and group record these home directories may also be inspected and
enumerated via userdbctl(1).
Home directories managed by systemd-homed.service are usually in one of two states, or in
a transition state between them: when "active" they are unlocked and mounted, and thus
accessible to the system and its programs; when "inactive" they are not mounted and thus
not accessible. Activation happens automatically at login of the user and usually can only
complete after a password (or other authentication token) has been supplied. Deactivation
happens after the user fully logged out. A home directory remains active as long as the
user is logged in at least once, i.e. has at least one login session. When the user logs
in a second time simultaneously the home directory remains active. It is deactivated only
after the last of the user's sessions ends.
OPTIONS
The following general options are understood (further options that control the various
properties of user records managed by systemd-homed.service are documented further down):
--identity=FILE
Read the user's JSON record from the specified file. If passed as "-" read the user
record from standard input. The supplied JSON object must follow the structure
documented in JSON User Records[1]. This option may be used in conjunction with the
create and update commands (see below), where it allows configuring the user record in
JSON as-is, instead of setting the individual user record properties (see below).
Added in version 245.
--json=FORMAT, -j
Controls whether to output the user record in JSON format, if the inspect command (see
below) is used. Takes one of "pretty", "short" or "off". If "pretty" human-friendly
whitespace and newlines are inserted in the output to make the JSON data more
readable. If "short" all superfluous whitespace is suppressed. If "off" (the default)
the user information is not shown in JSON format but in a friendly human readable
formatting instead. The -j option picks "pretty" when run interactively and "short"
otherwise.
Added in version 245.
--export-format=FORMAT, -E, -EE
When used with the inspect verb in JSON mode (see above) may be used to suppress
certain aspects of the JSON user record on output. Specifically, if "stripped" format
is used the binding and runtime fields of the record are removed. If "minimal" format
is used the cryptographic signature is removed too. If "full" format is used the full
JSON record is shown (this is the default). This option is useful for copying an
existing user record to a different system in order to create a similar user there
with the same settings. Specifically: homectl inspect -EE | ssh root@othersystem
homectl create -i- may be used as simple command line for replicating a user on
another host. -E is equivalent to -j --export-format=stripped, -EE to -j
--export-format=minimal. Note that when replicating user accounts user records
acquired in "stripped" mode will retain the original cryptographic signatures and thus
may only be modified when the private key to update them is available on the
destination machine. When replicating users in "minimal" mode, the signature is
removed during the replication and thus the record will be implicitly signed with the
key of the destination machine and may be updated there without any private key
replication.
Added in version 245.
--offline
Do not attempt to update the copy of the user record and blob directory that is
embedded inside of the home area. This allows for operation on home areas that are
absent, or without needing to authenticate as the user being modified.
Added in version 256.
-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.
USER RECORD PROPERTIES
The following options control various properties of the user records/home directories that
systemd-homed.service manages. These switches may be used in conjunction with the create
and update commands for configuring various aspects of the home directory and the user
account:
--real-name=NAME, -c NAME
The real name for the user. This corresponds with the GECOS field on classic UNIX NSS
records.
Added in version 245.
--realm=REALM
The realm for the user. The realm associates a user with a specific organization or
installation, and allows distinguishing users of the same name defined in different
contexts. The realm can be any string that also qualifies as valid DNS domain name,
and it is recommended to use the organization's or installation's domain name for this
purpose, but this is not enforced nor required. On each system only a single user of
the same name may exist, and if a user with the same name and realm is seen it is
assumed to refer to the same user while a user with the same name but different realm
is considered a different user. Note that this means that two users sharing the same
name but with distinct realms are not allowed on the same system. Assigning a realm to
a user is optional.
Added in version 245.
--email-address=EMAIL
Takes an electronic mail address to associate with the user. On log-in the $EMAIL
environment variable is initialized from this value.
Added in version 245.
--location=TEXT
Takes location specification for this user. This is free-form text, which might or
might not be usable by geo-location applications. Example: --location="Berlin,
Germany" or --location="Basement, Room 3a"
Added in version 245.
--icon-name=ICON
Takes an icon name to associate with the user, following the scheme defined by the
Icon Naming Specification[2].
Added in version 245.
--home-dir=PATH, -dPATH
Takes a path to use as home directory for the user. Note that this is the directory
the user's home directory is mounted to while the user is logged in. This is not where
the user's data is actually stored, see --image-path= for that. If not specified
defaults to /home/$USER.
Added in version 245.
--uid=UID
Takes a preferred numeric UNIX UID to assign this user. If a user is to be created
with the specified UID and it is already taken by a different user on the local system
then creation of the home directory is refused. Note though, if after creating the
home directory it is used on a different system and the configured UID is taken by
another user there, then systemd-homed may assign the user a different UID on that
system. The specified UID must be outside of the system user range. It is recommended
to use the 60001...60513 UID range for this purpose. If not specified, the UID is
automatically picked. If the home directory is found to be owned by a different UID
when logging in, the home directory and everything underneath it will have its
ownership changed automatically before login completes.
Note that changing this option for existing home directories generally has no effect
on home directories that already have been registered locally (have a local binding),
as the UID used for an account on the local system is determined when the home
directory is first activated on it, and then remains in effect until the home
directory is removed.
Note that users managed by systemd-homed always have a matching group associated with
the same name as well as a GID matching the UID of the user. Thus, configuring the GID
separately is not permitted.
Added in version 245.
--member-of=GROUP, -G GROUP
Takes a comma-separated list of auxiliary UNIX groups this user shall belong to.
Example: --member-of=wheel to provide the user with administrator privileges. Note
that systemd-homed does not manage any groups besides a group matching the user in
name and numeric UID/GID. Thus any groups listed here must be registered
independently, for example with groupadd(8). Any non-existent groups are ignored. This
option may be used more than once, in which case all specified group lists are
combined. If the user is currently a member of a group which is not listed, the user
will be removed from the group.
Added in version 245.
--capability-bounding-set=CAPABILITIES, --capability-ambient-set=CAPABILITIES
These options take a space separated list of process capabilities (e.g.
CAP_WAKE_ALARM, CAP_BLOCK_SUSPEND, ...) that shall be set in the capability bounding
and ambient sets for all the user's sessions. See capabilities(7) for details on the
capabilities concept. These options may be used more than once, in which case the
specified lists are combined. If the parameter begins with a "~" character the effect
is inverted: the specified capability is dropped from the specific set.
Added in version 254.
--skel=PATH
Takes a file system path to a directory. Specifies the skeleton directory to
initialize the home directory with. All files and directories in the specified path
are copied into any newly create home directory. If not specified defaults to
/etc/skel/.
Added in version 245.
--shell=SHELL
Takes a file system path. Specifies the shell binary to execute on terminal logins. If
not specified defaults to /bin/bash.
Added in version 245.
--setenv=VARIABLE[=VALUE]
Takes an environment variable assignment to set for all user processes. May be used
multiple times to set multiple environment variables. When "=" and VALUE are omitted,
the value of the variable with the same name in the program environment will be used.
Note that a number of other settings also result in environment variables to be set
for the user, including --email=, --timezone= and --language=.
Added in version 245.
--timezone=TIMEZONE
Takes a time zone location name that sets the timezone for the specified user. When
the user logs in the $TZ environment variable is initialized from this setting.
Example: --timezone=Europe/Amsterdam will result in the environment variable
"TZ=:Europe/Amsterdam". (":" is used intentionally as part of the timezone
specification, see tzset(3).)
Added in version 245.
--language=LANG
Takes a comma- or colon-separated list of languages preferred by the user, ordered by
descending priority. The $LANG and $LANGUAGE environment variables are initialized
from this value on login, and thus values suitible for these environment variables are
accepted here, for example --language=de_DE.UTF-8. This option may be used more than
once, in which case the language lists are concatenated.
Added in version 245.
--ssh-authorized-keys=KEYS
Either takes a SSH authorized key line to associate with the user record or a "@"
character followed by a path to a file to read one or more such lines from. SSH keys
configured this way are made available to SSH to permit access to this home directory
and user record. This option may be used more than once to configure multiple SSH
keys.
Added in version 245.
--pkcs11-token-uri=URI
Takes an RFC 7512 PKCS#11 URI referencing a security token (e.g. YubiKey or PIV
smartcard) that shall be able to unlock the user account. The security token URI
should reference a security token with exactly one pair of X.509 certificate and
private key. A random secret key is then generated, encrypted with the public key of
the X.509 certificate, and stored as part of the user record. At login time it is
decrypted with the PKCS#11 module and then used to unlock the account and associated
resources. See below for an example how to set up authentication with a security
token.
Instead of a valid PKCS#11 URI, the special strings "list" and "auto" may be
specified. If "list" is passed, a brief table of suitable, currently plugged in
PKCS#11 hardware tokens is shown, along with their URIs. If "auto" is passed, a
suitable PKCS#11 hardware token is automatically selected (this operation will fail if
there isn't exactly one suitable token discovered). The latter is a useful shortcut
for the most common case where a single PKCS#11 hardware token is plugged in.
Note that many hardware security tokens implement both PKCS#11/PIV and FIDO2 with the
"hmac-secret" extension (for example: the YubiKey 5 series), as supported with the
--fido2-device= option below. Both mechanisms are similarly powerful, though FIDO2 is
the more modern technology. PKCS#11/PIV tokens have the benefit of being recognizable
before authentication and hence can be used for implying the user identity to use for
logging in, which FIDO2 does not allow. PKCS#11/PIV devices generally require
initialization (i.e. storing a private/public key pair on them, see example below)
before they can be used; FIDO2 security tokens generally do not required that, and
work out of the box.
Added in version 245.
--fido2-credential-algorithm=STRING
Specify COSE algorithm used in credential generation. The default value is "es256".
Supported values are "es256", "rs256" and "eddsa".
"es256" denotes ECDSA over NIST P-256 with SHA-256. "rs256" denotes 2048-bit RSA with
PKCS#1.5 padding and SHA-256. "eddsa" denotes EDDSA over Curve25519 with SHA-512.
Note that your authenticator may choose not to support some algorithms.
Added in version 251.
--fido2-device=PATH
Takes a path to a Linux "hidraw" device (e.g. /dev/hidraw1), referring to a FIDO2
security token implementing the "hmac-secret" extension that shall be able to unlock
the user account. A random salt value is generated on the host and passed to the FIDO2
device, which calculates a HMAC hash of the salt using an internal secret key. The
result is then used as the key to unlock the user account. The random salt is included
in the user record, so that whenever authentication is needed it can be passed to the
FIDO2 token again.
Instead of a valid path to a FIDO2 "hidraw" device the special strings "list" and
"auto" may be specified. If "list" is passed, a brief table of suitable discovered
FIDO2 devices is shown. If "auto" is passed, a suitable FIDO2 token is automatically
selected, if exactly one is discovered. The latter is a useful shortcut for the most
common case where a single FIDO2 hardware token is plugged in.
Note that FIDO2 devices suitable for this option must implement the "hmac-secret"
extension. Most current devices (such as the YubiKey 5 series) do. If the extension is
not implemented the device cannot be used for unlocking home directories.
The FIDO2 device may be subsequently removed by setting the device path to an empty
string (e.g. homectl update $USER --fido2-device="").
Note that many hardware security tokens implement both FIDO2 and PKCS#11/PIV (and thus
may be used with either --fido2-device= or --pkcs11-token-uri=), for a discussion see
above.
Added in version 246.
--fido2-with-client-pin=BOOL
When enrolling a FIDO2 security token, controls whether to require the user to enter a
PIN when unlocking the account (the FIDO2 "clientPin" feature). Defaults to "yes".
(Note: this setting is without effect if the security token does not support the
"clientPin" feature at all, or does not allow enabling or disabling it.)
Added in version 249.
--fido2-with-user-presence=BOOL
When enrolling a FIDO2 security token, controls whether to require the user to verify
presence (tap the token, the FIDO2 "up" feature) when unlocking the account. Defaults
to "yes". (Note: this setting is without effect if the security token does not support
the "up" feature at all, or does not allow enabling or disabling it.)
Added in version 249.
--fido2-with-user-verification=BOOL
When enrolling a FIDO2 security token, controls whether to require user verification
when unlocking the account (the FIDO2 "uv" feature). Defaults to "no". (Note: this
setting is without effect if the security token does not support the "uv" feature at
all, or does not allow enabling or disabling it.)
Added in version 249.
--recovery-key=BOOL
Accepts a boolean argument. If enabled a recovery key is configured for the account. A
recovery key is a computer generated access key that may be used to regain access to
an account if the password has been forgotten or the authentication token lost. The
key is generated and shown on screen, and should be printed or otherwise transferred
to a secure location. A recovery key may be entered instead of a regular password to
unlock the account.
Added in version 247.
--blob=PATH, -b PATH, --blob=FILENAME=PATH, -b FILENAME=PATH
Accepts either a directory path, or a file name followed by a file path. If just a
directory path is specified, then the user's entire blob directory is replaced the
specified path. Note that this replacement is performed before per-file manipulations
are applied, which means these per-file manipulations will be applied on top of the
specified directory. If a filename and file path are specified, then the single
specified blob file will be overwritten with the specified path. If completely blank,
the entire blob directory is emptied out (which also resets all previous blob-related
flags up to this point). If a filename is specified but the corresponding path is
blank, that single file will be deleted from the blob directory. All changes are
performed in temporary copies of the specified files in directories, which means that
the originals specified on the command line are not modified. See User Record Blob
Directories[3] for more information about blob directories.
Added in version 256.
--avatar=PATH, --login-background=PATH
Accept a file path. If set, the specified file is used to overwrite the corresponding
file in the user's blob directory. If blank, the corresponding file is deleted from
the blob directory. Essentially, these options are shortcuts to --blob=FILENAME=PATH
for the known filenames defined in User Record Blob Directories[3].
Added in version 256.
--locked=BOOLEAN
Takes a boolean argument. Specifies whether this user account shall be locked. If true
logins into this account are prohibited, if false (the default) they are permitted (of
course, only if authorization otherwise succeeds).
Added in version 245.
--not-before=TIMESTAMP, --not-after=TIMESTAMP
These options take a timestamp string, in the format documented in systemd.time(7) and
configures points in time before and after logins into this account are not permitted.
Added in version 245.
--rate-limit-interval=SECS, --rate-limit-burst=NUMBER
Configures a rate limit on authentication attempts for this user. If the user attempts
to authenticate more often than the specified number, on a specific system, within the
specified time interval authentication is refused until the time interval passes.
Defaults to 10 times per 1min.
Added in version 245.
--password-hint=TEXT
Takes a password hint to store alongside the user record. This string is stored
accessible only to privileged users and the user itself and may not be queried by
other users. Example: --password-hint="My first pet's name".
Added in version 245.
--enforce-password-policy=BOOL, -P
Takes a boolean argument. Configures whether to enforce the system's password policy
for this user, regarding quality and strength of selected passwords. Defaults to on.
-P is short for ---enforce-password-policy=no.
Added in version 245.
--password-change-now=BOOL
Takes a boolean argument. If true the user is asked to change their password on next
login.
Added in version 245.
--password-change-min=TIME, --password-change-max=TIME, --password-change-warn=TIME,
--password-change-inactive=TIME
Each of these options takes a time span specification as argument (in the syntax
documented in systemd.time(7)) and configures various aspects of the user's password
expiration policy. Specifically, --password-change-min= configures how much time has
to pass after changing the password of the user until the password may be changed
again. If the user tries to change their password before this time passes the attempt
is refused. --password-change-max= configures how soon after it has been changed the
password expires and needs to be changed again. After this time passes logging in may
only proceed after the password is changed. --password-change-warn= specifies how
much earlier than then the time configured with --password-change-max= the user is
warned at login to change their password as it will expire soon. Finally
--password-change-inactive= configures the time which has to pass after the password
as expired until the user is not permitted to log in or change the password anymore.
Note that these options only apply to password authentication, and do not apply to
other forms of authentication, for example PKCS#11-based security token
authentication.
Added in version 245.
--disk-size=BYTES
Either takes a size in bytes as argument (possibly using the usual K, M, G, ...
suffixes for 1024 base values), a percentage value, or the special strings "min" or
"max", and configures the disk space to assign to the user. If a percentage value is
specified (i.e. the argument suffixed with "%") it is taken relative to the available
disk space of the backing file system. If specified as "min" assigns the minimal disk
space permitted by the constraints of the backing file system and other limits, when
specified as "max" assigns the maximum disk space available. If the LUKS2 backend is
used this configures the size of the loopback file and file system contained therein.
For the other storage backends configures disk quota using the filesystem's native
quota logic, if available. If not specified, defaults to 85% of the available disk
space for the LUKS2 backend and to no quota for the others.
Added in version 245.
--access-mode=MODE
Takes a UNIX file access mode written in octal. Configures the access mode of the home
directory itself. Note that this is only used when the directory is first created, and
the user may change this any time afterwards. Example: --access-mode=0700
Added in version 245.
--umask=MASK
Takes the access mode mask (in octal syntax) to apply to newly created files and
directories of the user ("umask"). If set this controls the initial umask set for all
login sessions of the user, possibly overriding the system's defaults.
Added in version 245.
--nice=NICE
Takes the numeric scheduling priority ("nice level") to apply to the processes of the
user at login time. Takes a numeric value in the range -20 (highest priority) to 19
(lowest priority).
Added in version 245.
--rlimit=LIMIT=VALUE[:VALUE]
Allows configuration of resource limits for processes of this user, see getrlimit(2)
for details. Takes a resource limit name (e.g. "LIMIT_NOFILE") followed by an equal
sign, followed by a numeric limit. Optionally, separated by colon a second numeric
limit may be specified. If two are specified this refers to the soft and hard limits,
respectively. If only one limit is specified the setting sets both limits in one.
Added in version 245.
--tasks-max=TASKS
Takes a non-zero unsigned integer as argument. Configures the maximum number of tasks
(i.e. threads, where each process is at least one thread) the user may have at any
given time. This limit applies to all tasks forked off the user's sessions, even if
they change user identity via su(1) or a similar tool. Use --rlimit=LIMIT_NPROC= to
place a limit on the tasks actually running under the UID of the user, thus excluding
any child processes that might have changed user identity. This controls the TasksMax=
setting of the per-user systemd slice unit user-$UID.slice. See systemd.resource-
control(5) for further details.
Added in version 245.
--memory-high=BYTES, --memory-max=BYTES
Set a limit on the memory a user may take up on a system at any given time in bytes
(the usual K, M, G, ... suffixes are supported, to the base of 1024). This includes
all memory used by the user itself and all processes they forked off that changed user
credentials. This controls the MemoryHigh= and MemoryMax= settings of the per-user
systemd slice unit user-$UID.slice. See systemd.resource-control(5) for further
details.
Added in version 245.
--cpu-weight=WEIGHT, --io-weight=WEIGHT
Set CPU and IO scheduling weights of the processes of the user, including those of
processes forked off by the user that changed user credentials. Takes a numeric value
in the range 1...10000. This controls the CPUWeight= and IOWeight= settings of the
per-user systemd slice unit user-$UID.slice. See systemd.resource-control(5) for
further details.
Added in version 245.
--storage=STORAGE
Selects the storage mechanism to use for this home directory. Takes one of "luks",
"fscrypt", "directory", "subvolume", "cifs". For details about these mechanisms, see
above. If a new home directory is created and the storage type is not specifically
specified, homed.conf(5) defines which default storage to use.
Added in version 245.
--image-path=PATH
Takes a file system path. Configures where to place the user's home directory. When
LUKS2 storage is used refers to the path to the loopback file, otherwise to the path
to the home directory (which may be in /home/ or any other accessible filesystem).
When unspecified defaults to /home/$USER.home when LUKS storage is used and
/home/$USER.homedir for the other storage mechanisms. Not defined for the "cifs"
storage mechanism. To use LUKS2 storage on a regular block device (for example a USB
stick) pass the path to the block device here. Specifying the path to a directory here
when using LUKS2 storage is not allowed. Similar, specifying the path to a regular
file or device node is not allowed if any of the other storage backends are used.
Added in version 245.
--drop-caches=BOOL
Automatically flush OS file system caches on logout. This is useful in combination
with the fscrypt storage backend to ensure the OS does not keep decrypted versions of
the files and directories in memory (and accessible) after logout. This option is also
supported on other backends, but should not bring any benefit there. Defaults to off,
except if the selected storage backend is fscrypt, where it defaults to on. Note that
flushing OS caches will negatively influence performance of the OS shortly after
logout.
Added in version 250.
--fs-type=TYPE
When LUKS2 storage is used configures the file system type to use inside the home
directory LUKS2 container. One of "btrfs", "ext4", "xfs". If not specified
homed.conf(5) defines which default file system type to use. Note that "xfs" is not
recommended as its support for file system resizing is too limited.
Added in version 245.
--luks-discard=BOOL
When LUKS2 storage is used configures whether to enable the "discard" feature of the
file system. If enabled the file system on top of the LUKS2 volume will report empty
block information to LUKS2 and the loopback file below, ensuring that empty space in
the home directory is returned to the backing file system below the LUKS2 volume,
resulting in a "sparse" loopback file. This option mostly defaults to off, since this
permits over-committing home directories which results in I/O errors if the underlying
file system runs full while the upper file system wants to allocate a block. Such I/O
errors are generally not handled well by file systems nor applications. When LUKS2
storage is used on top of regular block devices (instead of on top a loopback file)
the discard logic defaults to on.
Added in version 245.
--luks-offline-discard=BOOL
Similar to --luks-discard=, controls the trimming of the file system. However, while
--luks-discard= controls what happens when the home directory is active,
--luks-offline-discard= controls what happens when it becomes inactive, i.e. whether
to trim/allocate the storage when deactivating the home directory. This option
defaults to on, to ensure disk space is minimized while a user is not logged in.
Added in version 246.
--luks-extra-mount-options=OPTIONS
Takes a string containing additional mount options to use when mounting the LUKS
volume. If specified, this string will be appended to the default, built-in mount
options.
Added in version 250.
--luks-cipher=CIPHER, --luks-cipher-mode=MODE, --luks-volume-key-size=BYTES,
--luks-pbkdf-type=TYPE, --luks-pbkdf-hash-algorithm=ALGORITHM,
--luks-pbkdf-force-iterations=ITERATIONS, --luks-pbkdf-time-cost=SECONDS,
--luks-pbkdf-memory-cost=BYTES, --luks-pbkdf-parallel-threads=THREADS,
--luks-sector-size=BYTES
Configures various cryptographic parameters for the LUKS2 storage mechanism. See
cryptsetup(8) for details on the specific attributes.
Note that homectl uses bytes for key size, like /proc/crypto, but cryptsetup(8) uses
bits.
Added in version 245.
--auto-resize-mode=
Configures whether to automatically grow and/or shrink the backing file system on
login and logout. Takes one of the strings "off", "grow", "shrink-and-grow". Only
applies to the LUKS2 backend currently, and if the btrfs file system is used inside it
(since only then online growing/shrinking of the file system is supported). Defaults
to "shrink-and-grow", if LUKS2/btrfs is used, otherwise is off. If set to "off" no
automatic shrinking/growing during login or logout is done. If set to "grow" the home
area is grown to the size configured via --disk-size= should it currently be smaller.
If it already matches the configured size or is larger no operation is executed. If
set to "shrink-and-grow" the home area is also resized during logout to the minimal
size the used disk space and file system constraints permit. This mode thus ensures
that while a home area is activated it is sized to the configured size, but while
deactivated it is compacted taking up only the minimal space possible. Note that if
the system is powered off abnormally or if the user otherwise not logged out cleanly
the shrinking operation will not take place, and the user has to re-login/logout again
before it is executed again.
Added in version 250.
--rebalance-weight=
Configures the weight parameter for the free disk space rebalancing logic. Only
applies to the LUKS2 backend (since for the LUKS2 backend disk space is allocated from
a per-user loopback file system instead of immediately from a common pool like the
other backends do it). In regular intervals free disk space in the active home areas
and their backing storage is redistributed among them, taking the weight value
configured here into account. Expects an integer in the range 1...10000, or the
special string "off". If not specified defaults to 100. The weight is used to scale
free space made available to the home areas: a home area with a weight of 200 will get
twice the free space as one with a weight of 100; a home area with a weight of 50 will
get half of that. The backing file system will be assigned space for a weight of 20.
If set to "off" no automatic free space distribution is done for this home area. Note
that resizing the home area explicitly (with homectl resize see below) will implicitly
turn off the automatic rebalancing. To reenable the automatic rebalancing use
--rebalance-weight= with an empty parameter.
Added in version 250.
--nosuid=BOOL, --nodev=BOOL, --noexec=BOOL
Configures the "nosuid", "nodev" and "noexec" mount options for the home directories.
By default "nodev" and "nosuid" are on, while "noexec" is off. For details about these
mount options see mount(8).
Added in version 245.
--cifs-domain=DOMAIN, --cifs-user-name=USER, --cifs-service=SERVICE,
--cifs-extra-mount-options=OPTIONS
Configures the Windows File Sharing (CIFS) domain and user to associate with the home
directory/user account, as well as the file share ("service") to mount as directory.
The latter is used when "cifs" storage is selected. The file share should be specified
in format "//host/share/directory/...". The directory part is optional — if not
specified the home directory will be placed in the top-level directory of the share.
The --cifs-extra-mount-options= setting allows specifying additional mount options
when mounting the share, see mount.cifs(8) for details.
Added in version 245.
--stop-delay=SECS
Configures the time the per-user service manager shall continue to run after the all
sessions of the user ended. The default is configured in logind.conf(5) (for home
directories of LUKS2 storage located on removable media this defaults to 0 though). A
longer time makes sure quick, repetitive logins are more efficient as the user's
service manager doesn't have to be started every time.
Added in version 245.
--kill-processes=BOOL
Configures whether to kill all processes of the user on logout. The default is
configured in logind.conf(5).
Added in version 245.
--auto-login=BOOL
Takes a boolean argument. Configures whether the graphical UI of the system should
automatically log this user in if possible. Defaults to off. If less or more than one
user is marked this way automatic login is disabled.
Added in version 245.
--session-launcher=LAUNCHER
Takes a string argument. Configures the user's preferred session launcher .desktop
entry file (i.e. "gnome", "plasma", or other names that appear in
/usr/share/xesssions/ or /usr/share/wayland-sessions). This is read by the display
manager to pick the default session that is launched when the user logs in.
Added in version 256.
--session-type=TYPE
Takes a string argument. Configures the user's preferred session type (i.e. "x11",
"wayland", and other values accepted by $XDG_SESSION_TYPE). This is read by the
display manage to pick the default session type the user is logged into.
Added in version 256.
COMMANDS
The following commands are understood:
list
List all home directories (along with brief details) currently managed by
systemd-homed.service. This command is also executed if none is specified on the
command line. (Note that the list of users shown by this command does not include
users managed by other subsystems, such as system users or any traditional users
listed in /etc/passwd.)
Added in version 245.
activate USER [USER...]
Activate one or more home directories. The home directories of each listed user will
be activated and made available under their mount points (typically in /home/$USER).
Note that any home activated this way stays active indefinitely, until it is
explicitly deactivated again (with deactivate, see below), or the user logs in and out
again and it thus is deactivated due to the automatic deactivation-on-logout logic.
Activation of a home directory involves various operations that depend on the selected
storage mechanism. If the LUKS2 mechanism is used, this generally involves: inquiring
the user for a password, setting up a loopback device, validating and activating the
LUKS2 volume, checking the file system, mounting the file system, and potentially
changing the ownership of all included files to the correct UID/GID.
Added in version 245.
deactivate USER [USER...]
Deactivate one or more home directories. This undoes the effect of activate.
Added in version 245.
inspect USER [USER...]
Show various details about the specified home directories. This shows various
information about the home directory and its user account, including runtime data such
as current state, disk use and similar. Combine with --json= to show the detailed JSON
user record instead, possibly combined with --export-format= to suppress certain
aspects of the output.
Added in version 245.
authenticate USER [USER...]
Validate authentication credentials of a home directory. This queries the caller for a
password (or similar) and checks that it correctly unlocks the home directory. This
leaves the home directory in the state it is in, i.e. it leaves the home directory in
inactive state if it was inactive before, and in active state if it was active before.
Added in version 245.
create USER, create --identity=PATH [USER]
Create a new home directory/user account of the specified name. Use the various user
record property options (as documented above) to control various aspects of the home
directory and its user accounts.
The specified user name should follow the strict syntax described on User/Group Name
Syntax[4].
Added in version 245.
remove USER
Remove a home directory/user account. This will remove both the home directory's user
record and the home directory itself, and thus delete all files and directories owned
by the user.
Added in version 245.
update USER, update --identity=PATH [USER]
Update a home directory/user account. Use the various user record property options (as
documented above) to make changes to the account, or alternatively provide a full,
updated JSON user record via the --identity= option.
Note that changes to user records not signed by a cryptographic private key available
locally are not permitted, unless --identity= is used with a user record that is
already correctly signed by a recognized private key.
Added in version 245.
passwd USER
Change the password of the specified home directory/user account.
Added in version 245.
resize USER BYTES
Change the disk space assigned to the specified home directory. If the LUKS2 storage
mechanism is used this will automatically resize the loopback file and the file system
contained within. Note that if "ext4" is used inside of the LUKS2 volume, it is
necessary to deactivate the home directory before shrinking it (i.e the user has to
log out). Growing can be done while the home directory is active. If "xfs" is used
inside of the LUKS2 volume the home directory may not be shrunk whatsoever. On all
three of "ext4", "xfs" and "btrfs" the home directory may be grown while the user is
logged in, and on the latter also shrunk while the user is logged in. If the
"subvolume", "directory", "fscrypt" storage mechanisms are used, resizing will change
file system quota. The size parameter may make use of the usual suffixes B, K, M, G, T
(to the base of 1024). The special strings "min" and "max" may be specified in place
of a numeric size value, for minimizing or maximizing disk space assigned to the home
area, taking constraints of the file system, disk usage inside the home area and on
the backing storage into account.
Added in version 245.
lock USER
Temporarily suspend access to the user's home directory and remove any associated
cryptographic keys from memory. Any attempts to access the user's home directory will
stall until the home directory is unlocked again (i.e. re-authenticated). This
functionality is primarily intended to be used during system suspend to make sure the
user's data cannot be accessed until the user re-authenticates on resume. This
operation is only defined for home directories that use the LUKS2 storage mechanism.
Added in version 245.
unlock USER
Resume access to the user's home directory again, undoing the effect of lock above.
This requires authentication of the user, as the cryptographic keys required for
access to the home directory need to be reacquired.
Added in version 245.
lock-all
Execute the lock command on all suitable home directories at once. This operation is
generally executed on system suspend (i.e. by systemctl suspend and related commands),
to ensure all active user's cryptographic keys for accessing their home directories
are removed from memory.
Added in version 245.
deactivate-all
Execute the deactivate command on all active home directories at once. This operation
is generally executed on system shut down (i.e. by systemctl poweroff and related
commands), to ensure all active user's home directories are fully deactivated before
/home/ and related file systems are unmounted.
Added in version 247.
with USER COMMAND...
Activate the specified user's home directory, run the specified command (under the
caller's identity, not the specified user's) and deactivate the home directory
afterwards again (unless the user is logged in otherwise). This command is useful for
running privileged backup scripts and such, but requires authentication with the
user's credentials in order to be able to unlock the user's home directory.
Added in version 245.
rebalance
Rebalance free disk space between active home areas and the backing storage. See
--rebalance-weight= above. This executes no operation unless there's at least one
active LUKS2 home area that has disk space rebalancing enabled. This operation is
synchronous: it will only complete once disk space is rebalanced according to the
rebalancing weights. Note that rebalancing also takes place automatically in the
background in regular intervals. Use this command to synchronously ensure disk space
is properly redistributed before initiating an operation requiring large amounts of
disk space.
Added in version 250.
firstboot
This command is supposed to be invoked during the initial boot of the system. It
checks whether any regular home area exists so far, and if not queries the user
interactively on the console for user name and password and creates one.
Alternatively, if one or more service credentials whose name starts with
"home.create." are passed to the command (containing a user record in JSON format)
these users are automatically created at boot.
This command is invoked by the systemd-homed-firstboot.service service unit.
Added in version 256.
CREDENTIALS
When invoked with the firstboot command, homectl supports the service credentials logic as
implemented by ImportCredential=/LoadCredential=/SetCredential= (see systemd.exec(5) for
details). The following credentials are used when passed in:
home.create.*
If one or more credentials whose names begin with "home.create.", followed by a valid
UNIX username are passed, a new home area is created, one for each specified user
record.
Added in version 256.
KERNEL COMMAND LINE
systemd.firstboot=
This boolean will disable the effect of homectl firstboot command. It's primarily
interpreted by systemd-firstboot(1).
Added in version 256.
EXIT STATUS
On success, 0 is returned, a non-zero failure code otherwise.
When a command is invoked with with, the exit status of the child is propagated.
Effectively, homectl will exit without error if the command is successfully invoked and
finishes successfully.
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 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.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well as $PAGER) will be
silently 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
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.
EXAMPLES
Example 1. Create a user "waldo" in the administrator group "wheel", and assign 500 MiB
disk space to them.
homectl create waldo --real-name="Waldo McWaldo" -G wheel --disk-size=500M
Example 2. Create a user "wally" on a USB stick, and assign a maximum of 500 concurrent
tasks to them.
homectl create wally --real-name="Wally McWally" --image-path=/dev/disk/by-id/usb-SanDisk_Ultra_Fit_476fff954b2b5c44-0:0 --tasks-max=500
Example 3. Change nice level of user "odlaw" to +5 and make sure the environment variable
$SOME is set to the string "THING" for them on login.
homectl update odlaw --nice=5 --setenv=SOME=THING
Example 4. Set up authentication with a YubiKey security token using PKCS#11/PIV:
# Clear the Yubikey from any old keys (careful!)
ykman piv reset
# Generate a new private/public key pair on the device, store the public key in 'pubkey.pem'.
ykman piv generate-key -a RSA2048 9d pubkey.pem
# Create a self-signed certificate from this public key, and store it on the device.
ykman piv generate-certificate --subject "Knobelei" 9d pubkey.pem
# We don't need the public key on disk anymore
rm pubkey.pem
# Allow the security token to unlock the account of user 'lafcadio'.
homectl update lafcadio --pkcs11-token-uri=auto
Example 5. Set up authentication with a FIDO2 security token:
# Allow a FIDO2 security token to unlock the account of user 'nihilbaxter'.
homectl update nihilbaxter --fido2-device=auto
SEE ALSO
systemd(1), systemd-homed.service(8), homed.conf(5), userdbctl(1), useradd(8),
cryptsetup(8)
NOTES
1. JSON User Records
https://systemd.io/USER_RECORD
2. Icon Naming Specification
https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
3. User Record Blob Directories
https://systemd.io/USER_RECORD_BLOB_DIRS
4. User/Group Name Syntax
https://systemd.io/USER_NAMES