systemd.system-credentials — System Credentials
System and Service Credentials are data objects that may be passed into booted systems or system services as they are invoked. They can be acquired from various external sources, and propagated into the system and from there into system services. Credentials may optionally be encrypted with a machine-specific key and/or locked to the local TPM2 device, and are only decrypted when the consuming service is invoked.
System credentials may be used to provision and configure various aspects of the system. Depending on the consuming component credentials are only used on initial invocations or are needed for all invocations.
Credentials may be used for any kind of data, binary or text, and may carry passwords, secrets, certificates, cryptographic key material, identity information, configuration, and more.
firstboot.keymap¶The console key mapping to set (e.g. "de"). Read by
systemd-firstboot(1),
and only honoured if no console keymap has been configured before.
firstboot.hostname¶This credential specifies the static system hostname to set during first boot. The
user will not be prompted for the hostname. Note that this controls the static hostname, not the transient
hostname, and only has an effect on first boot, unlike system.hostname (see
below). Read by
systemd-firstboot(1)
and only honoured if no static hostname has been configured before. The value may use the wildcard
patterns documented in
hostname(5) (e.g.
"$-$" or "foo-????"). When the credential is applied on the running
system (the usual case, by systemd-firstboot.service on first boot), the wildcards
are resolved against the machine ID and the resulting concrete name is written to
/etc/hostname. The name is thus persisted once at first boot and
does not change on subsequent boots even if the word lists are later updated or the pattern is changed
(for example to add more "?"/"$" tokens for additional entropy), which is the recommended
way to obtain a stable, per-machine generated hostname. (When
systemd-firstboot(1)
operates on an offline image via --root=/--image=, the target's
machine ID is not yet known, so the pattern is written verbatim and, like a pattern placed directly in
/etc/hostname, re-derived on every boot rather than persisted.)
firstboot.locale, firstboot.locale-messages¶The system locale to set (e.g. "de_DE.UTF-8"). Read by
systemd-firstboot(1),
and only honoured if no locale has been configured before. firstboot.locale sets
"LANG", while firstboot.locale-message sets
"LC_MESSAGES".
firstboot.timezone¶The system timezone to set (e.g. "Europe/Berlin"). Read by
systemd-firstboot(1),
and only honoured if no system timezone has been configured before.
The machine tags to set, as a colon-separated list (e.g.
"webserver:frontend:berlin"). Read by
systemd-firstboot(1),
and only honoured if /etc/machine-info has not been configured before. Written
into the TAGS= field of that file, see
machine-info(5) for
details.
login.issue¶The data of this credential is written to
/etc/issue.d/50-provision.conf, if the file does not exist yet.
agetty(8)
reads this file and shows its contents at the login prompt of terminal logins. See
issue(5)
for details.
Consumed by /usr/lib/tmpfiles.d/provision.conf, see
tmpfiles.d(5).
login.motd¶The data of this credential is written to /etc/motd.d/50-provision.conf,
if the file does not exist yet.
pam_motd(8)
reads this file and shows its contents as "message of the day" during terminal logins. See
motd(5)
for details.
Consumed by /usr/lib/tmpfiles.d/provision.conf, see
tmpfiles.d(5).
network.hosts¶The data of this credential is written to /etc/hosts, if the file
does not exist yet. See
hosts(5)
for details.
Consumed by /usr/lib/tmpfiles.d/provision.conf, see
tmpfiles.d(5).
network.dns, network.search_domains¶DNS server information and search domains. Read by systemd-resolved.service(8).
network.conf.*, network.link.*, network.netdev.*, network.network.*¶Configures network devices. Read by
systemd-network-generator.service(8).
These credentials should contain valid
networkd.conf(5),
systemd.link(5),
systemd.netdev(5),
systemd.network(5)
configuration data. From each matching credential a separate file is created. Example: the contents
of a credential network.link.50-foobar will be copied into a file
50-foobar.link.
Note that the resulting files are created world-readable, it is hence recommended to not include
secrets in these credentials, but supply them via separate credentials directly to
systemd-networkd.service, e.g. network.wireguard.*
as described below.
network.wireguard.*¶Configures secrets for WireGuard netdevs. Read by
systemd-networkd.service(8).
For more information, refer to the [WireGuard] section of
systemd.netdev(5).
passwd.hashed-password.root, passwd.plaintext-password.root¶May contain the password (either in UNIX hashed format, or in plaintext) for the root users. Read by both systemd-firstboot(1) and systemd-sysusers(8), and only honoured if no root password has been configured before.
passwd.shell.root¶The path to the shell program (e.g. "/bin/bash") for the root user. Read by
both
systemd-firstboot(1)
and
systemd-sysusers(8),
and only honoured if no root shell has been configured before.
Provides additional public keys, given in the customary authorized_keys
format, for all users, for incoming connections via the generated AF_VSOCK
and AF_UNIX socket units.
The intended use of this is for a host system (in either VM or container configurations) to generate a keypair and inject the public key into the guest, using the private key to connect to any user account on the guest via ssh, without further authentication.
Consumed by systemd-ssh-generator(8).
The data of this credential is written to /root/.ssh/authorized_keys, if
the file does not exist yet. This allows provisioning SSH access for the system's root user.
Consumed by /usr/lib/tmpfiles.d/provision.conf, see
tmpfiles.d(5).
ssh.listen¶May be used to configure SSH sockets the system shall be reachable on. See systemd-ssh-generator(8) for details.
sysusers.extra¶Additional sysusers.d(5) lines to process during boot.
sysctl.extra¶Additional sysctl.d(5) lines to process during boot.
tmpfiles.extra¶Additional tmpfiles.d(5) lines to process during boot.
fstab.extra¶Additional mounts to establish at boot. For details, see systemd-fstab-generator(8).
vconsole.keymap, vconsole.keymap_toggle, vconsole.font, vconsole.font_map, vconsole.font_unimap¶Console settings to apply, see systemd-vconsole-setup.service(8) for details.
getty.auto¶Used for controlling the execution mode of systemd-getty-generator. See
systemd-getty-generator(8) for details.
getty.ttys.serial, getty.ttys.container¶Used for spawning additional login prompts, see systemd-getty-generator(8) for details.
journal.forward_to_socket¶Used by systemd-journald(8) to determine where to forward log messages for socket forwarding, see journald.conf(5) for details.
journal.storage¶Used by systemd-journald(8) to determine where to store journal files, see journald.conf(5) for details.
vmm.notify_socket¶Configures an
sd_notify(3)
compatible AF_VSOCK socket the service manager will report status information,
ready notification and exit status on. For details see
systemd(1).
shell.prompt.prefix, shell.prompt.suffix¶Defines strings to prefix and suffix any interactive UNIX shell prompt with. For details see pam_systemd(8).
shell.welcome¶Define a string to print when an interactive UNIX shell initializes. For details see pam_systemd(8).
system.machine_id¶Takes a 128bit ID to initialize the machine ID from (if it is not set yet). Interpreted by the service manager (PID 1). For details see systemd(1).
system.hostname¶Accepts a (transient) hostname to configure during early boot. The static hostname specified
in /etc/hostname, if configured, takes precedence over this setting.
Interpreted by the service manager (PID 1). For details see
systemd(1). Also
see firstboot.hostname above. The value may use the wildcard patterns documented
in hostname(5)
("?" and "$"), which are expanded deterministically from the
machine ID when the credential is applied. As this is a transient hostname that is re-applied on
every boot, a wildcard value is re-derived each boot (and may change if the word lists change) and
is never persisted; pass an already-resolved name if a stable hostname is required. Note also that
the word-list tokens require the word lists to be present, which is generally not the case in the
initrd so during initrd the default hostname is used and in late boot the resolved one becomes
available.
home.add-signing-key.*¶Adds a new signing key for user records to the system. The credential contents should contain
a user signing key, for example as reported by homectl get-signing-key. Multiple
keys may be specified, and they will be put in place under the name of the credential name suffix
(which must itself carry the .public suffix). For details see
homectl(1).
home.create.*¶Creates a new home area for the specified user with the user record data passed in. For details see homectl(1).
home.register.*¶Registers an existing home area for the specified user with the user record data passed in. For details see homectl(1).
cryptsetup.passphrase, cryptsetup.tpm2-pin, cryptsetup.fido2-pin, cryptsetup.pkcs11-pin, cryptsetup.luks2-pin¶Specifies the passphrase/PINs to use for unlock encrypted storage volumes. For details see systemd-cryptsetup(8).
systemd.extra-unit.*, systemd.unit-dropin.*¶These credentials specify extra units and drop-ins to add to the system. For details see systemd-debug-generator(8).
udev.conf.*, udev.rules.*¶Configures udev configuration file and udev rules. Read by
systemd-udev-load-credentials.service, which invokes
udevadm control --load-credentials. These credentials directly translate to a
matching
udev.conf(5) or
udev(7) rules
file. Example: the contents of a credential
udev.conf.50-foobar will be copied into a file
/run/udev/udev.conf.d/50-foobar.conf, and
udev.rules.50-foobar will be copied into a file
/run/udev/rules.d/50-foobar.rules. See
udev(7),
udev.conf(5), and
udevadm(8)
for details.
import.pull¶Specified disk images (tarballs and DDIs) to automatically download and install at boot. For details see systemd-import-generator(8).
userdb.user.*, userdb.group.*, userdb.transient.user.*, userdb.transient.group.*¶Configure JSON user and group records. Read by
systemd-userdb-load-credentials.service, which invokes
userdbctl load-credentials. These credentials directly translate to
matching
JSON User and
JSON Group records. Example: the contents of a
credential userdb.user.foobar will be copied into a file
/etc/userdb/foobar.user, and
userdb.group.foobar will be copied into a file
/etc/userdb/foobar.group. Symlinks for the uid/gid will also be created in
/etc/userdb/, as well as the corresponding.membership
files. See
systemd-userdbd.service(7),
nss-systemd(8), and
userdbctl(1)
for details.
Any passed user records must contain uid and gid fields. Any passed group records must
contain a gid field. For both user and group records, the credential suffix (for
"userdb.user.foobar" the suffix is "foobar") must match the user
or group name field from the user or group record.
Note that the records created for userdb.user.* and
userdb.group.* credentials are created in /etc/userdb/ and
the records created for userdb.transient.user.* and
userdb.transient.group.* are created in /run/userdb/
(/etc/passwd and /etc/group are not modified).
fsck.*¶Read by systemd-fsck@.service,
systemd-fsck-root.service, and systemd-fsck-usr.service.
See
systemd-fsck@.service(8)
for more details.
quotacheck.*¶Read by systemd-quotacheck@.service and
systemd-quotacheck-root.service. See
systemd-quotacheck(8)
for more details.
imds.*¶Read by systemd-imdsd@.service(8).