The following options are understood:

--root=root

Takes a directory path as an argument. All paths will be prefixed with the given alternate root path, including config search paths. This is useful to operate on a system image mounted to the specified directory instead of the host system itself.

Added in version 216.

--image=path

Takes a path to a disk image file or block device node. If specified all operations are applied to file system in the indicated disk image. This is similar to --root= but operates on file systems stored in disk images or block devices. The disk image should either contain just a file system or a set of file systems within a GPT partition table, following the Discoverable Partitions Specification[1]. For further information on supported disk images, see systemd-nspawn(1)s switch of the same name.

Added in version 246.

--locale=LOCALE, --locale-messages=LOCALE

Sets the system locale, more specifically the LANG= and LC_MESSAGES settings. The argument should be a valid locale identifier, such as "de_DE.UTF-8". This controls the locale.conf(5) configuration file.

Added in version 216.

--keymap=KEYMAP

Sets the system keyboard layout. The argument should be a valid keyboard map, such as "de-latin1". This controls the "KEYMAP" entry in the vconsole.conf(5) configuration file.

Added in version 236.

--timezone=TIMEZONE

Sets the system time zone. The argument should be a valid time zone identifier, such as "Europe/Berlin". This controls the localtime(5) symlink.

Added in version 216.

--hostname=HOSTNAME

Sets the system hostname. The argument should be a hostname, compatible with DNS. This controls the hostname(5) configuration file.

Added in version 216.

--setup-machine-id

Initialize the systems machine ID to a random ID. This controls the machine-id(5) file.

This option only works in combination with --root= or --image=. On a running system, machine-id is written by the manager with help from systemd-machine-id-commit.service(8).

Added in version 216.

--machine-id=ID

Set the systems machine ID to the specified value. The same restrictions apply as to --setup-machine-id.

Added in version 216.

--root-password=PASSWORD, --root-password-file=PATH, --root-password-hashed=HASHED_PASSWORD

Sets the password of the systems root user. This creates/modifies the passwd(5) and shadow(5) files. This setting exists in three forms: --root-password= accepts the password to set directly on the command line, --root-password-file= reads it from a file and --root-password-hashed= accepts an already hashed password on the command line. See shadow(5) for more information on the format of the hashed password. Note that it is not recommended to specify plaintext passwords on the command line, as other users might be able to see them simply by invoking ps(1).

Added in version 216.

--root-shell=SHELL

Sets the shell of the systems root user. This creates/modifies the passwd(5) file.

Added in version 246.

--kernel-command-line=CMDLINE

Sets the systems kernel command line. This controls the /etc/kernel/cmdline file which is used by kernel-install(8).

Added in version 246.

--prompt-locale, --prompt-keymap, --prompt-timezone, --prompt-hostname, --prompt-root-password, --prompt-root-shell

Prompt the user interactively for a specific basic setting. Note that any explicit configuration settings specified on the command line take precedence, and the user is not prompted for it.

Added in version 216.

--prompt

Query the user for locale, keymap, timezone, hostname, roots password, and roots shell. This is equivalent to specifying --prompt-locale, --prompt-keymap, --prompt-timezone, --prompt-hostname, --prompt-root-password, --prompt-root-shell in combination.

Added in version 216.

--copy-locale, --copy-keymap, --copy-timezone, --copy-root-password, --copy-root-shell

Copy a specific basic setting from the host. This only works in combination with --root= or --image=.

Added in version 216.

--copy

Copy locale, keymap, time zone, root password and shell from the host. This is equivalent to specifying --copy-locale, --copy-keymap, --copy-timezone, --copy-root-password, --copy-root-shell in combination.

Added in version 216.

--force

Write configuration even if the relevant files already exist. Without this option, systemd-firstboot doesnt modify or replace existing files. Note that when configuring the root account, even with this option, systemd-firstboot only modifies the entry of the "root" user, leaving other entries in /etc/passwd and /etc/shadow intact.

Added in version 246.

--reset

If specified, all existing files that are configured by systemd-firstboot are removed. Note that the files are removed regardless of whether theyll be configured with a new value or not. This operation ensures that the next boot of the image will be considered a first boot, and systemd-firstboot will prompt again to configure each of the removed files.

Added in version 254.

--delete-root-password

Removes the password of the systems root user, enabling login as root without a password unless the root account is locked. Note that this is extremely insecure and hence this option should not be used lightly.

Added in version 246.

--welcome=

Takes a boolean argument. By default when prompting the user for configuration options a brief welcome text is shown before the first question is asked. Pass false to this option to turn off the welcome text.

Added in version 246.

-h, --help

Print a short help text and exit.

--version

Print a short version string and exit.

systemd-firstboot 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:

passwd.hashed-password.root, passwd.plaintext-password.root

A hashed or plaintext version of the root password to use, in place of prompting the user. These credentials are equivalent to the same ones defined for the systemd-sysusers.service(8) service.

Added in version 249.

passwd.shell.root

Specifies the shell binary to use for the specified account. Equivalent to the credential of the same name defined for the systemd-sysusers.service(8) service.

Added in version 249.

firstboot.locale, firstboot.locale-messages

These credentials specify the locale settings to set during first boot, in place of prompting the user.

Added in version 249.

firstboot.keymap

This credential specifies the keyboard setting to set during first boot, in place of prompting the user.

Note the relationship to the vconsole.keymap credential understood by systemd-vconsole-setup.service(8): both ultimately affect the same setting, but firstboot.keymap is written into /etc/vconsole.conf on first boot (if not already configured), and then read from there by systemd-vconsole-setup, while vconsole.keymap is read on every boot, and is not persisted to disk (but any configuration in vconsole.conf will take precedence if present).

Added in version 249.

firstboot.timezone

This credential specifies the system timezone setting to set during first boot, in place of prompting the user.

Added in version 249.

Note that by default the systemd-firstboot.service unit file is set up to inherit the listed credentials from the service manager. Thus, when invoking a container with an unpopulated /etc/ for the first time it is possible to configure the root users password to be "systemd" like this:

.RS 4

# systemd-nspawn --image=... --set-credential=firstboot.locale:de_DE.UTF-8 ...

.RE

Note that these credentials are only read and applied during the first boot process. Once they are applied they remain applied for subsequent boots, and the credentials are not considered anymore.

On success, 0 is returned, a non-zero failure code otherwise.

systemd.firstboot=

Takes a boolean argument, defaults to on. If off, systemd-firstboot.service wont interactively query the user for basic settings at first boot, even if those settings are not initialized yet.

Added in version 233.

1.

Discoverable Partitions Specification

https://uapi-group.org/specifications/specs/discoverable_partitions_specification