Provided by: systemd-homed_253.5-1ubuntu6.1_amd64 bug

NAME

       homectl - 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 an 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).

       --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.

       --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.

       -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.

       --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.

       --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.

       --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"

       --icon-name=ICON
           Takes an icon name to associate with the user, following the scheme defined by the
           Icon Naming Specification[2].

       --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.

       --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 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.

       --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.

       --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/.

       --shell=SHELL
           Takes a file system path. Specifies the shell binary to execute on terminal logins. If
           not specified defaults to /bin/bash.

       --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=.

       --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).)

       --language=LANG
           Takes a specifier indicating the preferred language of the user. The $LANG environment
           variable is initialized from this value on login, and thus a value suitable for this
           environment variable is accepted here, for example --language=de_DE.UTF8.

       --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.

       --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.

       --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 not support some algorithms.

       --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.

       --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.)

       --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.)

       --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.)

       --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.

       --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).

       --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.

       --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.

       --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".

       --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.

       --password-change-now=BOOL
           Takes a boolean argument. If true the user is asked to change their password on next
           login.

       --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.

       --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.

       --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

       --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.

       --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).

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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.

       --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).

       --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.

       --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.

       --kill-processes=BOOL
           Configures whether to kill all processes of the user on logout. The default is
           configured in logind.conf(5).

       --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.

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.)

       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.

       deactivate USER [USER...]
           Deactivate one or more home directories. This undoes the effect of activate.

       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.

       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.

       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[3].

       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.

       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.

       passwd USER
           Change the password of the specified home directory/user account.

       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.

       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.

       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.

       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.

       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.

       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.

       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.

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). 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.

       $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_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.

           See less(1) for more discussion.

       $SYSTEMD_LESSCHARSET
           Override the charset passed to less (by default "utf-8", if the invoking terminal is
           determined to be UTF-8 compatible).

       $SYSTEMD_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/Group Name Syntax
           https://systemd.io/USER_NAMES