ADDUSER.CONF(5)

NAME
/etc/adduser.conf - configuration file for adduser(8) and addgroup(8)

DESCRIPTION
The file /etc/adduser.conf contains defaults for the programs adduser(8), addgroup(8), deluser(8) and delgroup(8). Each line holds a single value pair in the form option = value. Double or single quotes are allowed around the value, as is whitespace around the equals sign. Comment lines must have a hash sign (#) in the first column.

The valid configuration options are:

STDERRMSGLEVEL ,  STDOUTMSGLEVEL , and  LOGMSGLEVEL
    Minimum priority for messages logged to syslog/journal and the console, respectively. See LOGGING in adduser(8). Defaults to warn for STDOUTMSGLEVEL and STDERRMSGLEVEL and info for LOGMSGLEVEL.

ADD_EXTRA_GROUPS
    Setting this to something other than 0 will cause adduser to add newly created non-system users to the list of groups defined by EXTRA_GROUPS (below). Defaults to 0.

DIR_MODE
    The permissions mode for home directories of non-system users that are created by adduser(8). Defaults to 0700. Note that there are potential configurations (such as ~/user web services, or in-home mail delivery) which will require changes to the default. See also SYS_DIR_MODE.

DHOME
    The directory in which new home directories should be created. Defaults to /home.

DSHELL
    The login shell to be used for all new users. Defaults to /bin/bash.

EXTRA_GROUPS
    This is the space-separated list of groups that new non-system users will be added to. Defaults to users.

FIRST_SYSTEM_GID  and  LAST_SYSTEM_GID
    specify an inclusive range of GIDs from which GIDs for system groups can be dynamically allocated. Defaults to 100 - 999.

FIRST_GID  and  LAST_GID
    specify an inclusive range of GIDs from which GIDs for non-system groups can be dynamically allocated. Defaults to 1000 - 59999.

FIRST_SYSTEM_UID  and  LAST_SYSTEM_UID
    specify an inclusive range of UIDs from which UIDs for system users can be dynamically allocated. Defaults to 100 - 999. Please note that system software, such as the users allocated by the base-passwd package, may assume that UIDs less than 100 are unallocated.

FIRST_UID  and  LAST_UID
    specify an inclusive range of UIDs from which UIDs for non-system users can be dynamically allocated. Defaults to 1000 - 59999.

GID_POOL
    See UID_POOL.

LAST_SYSTEM_GID
LAST_GID
LAST_SYSTEM_UID
LAST_UID
    See the FIRST_ variants of the option.

NAME_REGEX
    Non-system user- and groupnames are checked against this regular expression. If the name doesn't match this regexp, user and group creation in adduser(8) is refused unless --allow-bad-names is set. With --allow-bad-names set, weaker checks are performed. Defaults to the most conservative ^[a-zA-Z][a-zA-Z0-9_-]*\$?$. See SYS_NAME_REGEX and Valid names, below, for more information.

RESERVE_UID_POOL  and  RESERVE_GID_POOL
    Controls whether the UID and GID values that are listed in the pool files are truly reserved. See UID AND GID POOLS in the NOTES section. Defaults to yes.

SKEL
    The directory from which skeletal user configuration files will be copied. Defaults to /etc/skel.

SKEL_IGNORE_REGEX
    When populating the newly created home directory of a non-system user, files in SKEL matching this regex are not copied. Defaults to to (.(dpkg|ucf)-(old|new|dist)$), the regular expression matching files left over from unmerged config files.

SYS_DIR_MODE
    The permissions mode for home directories of system users that are created by adduser(8). Defaults to 0755. Note that changing the default permissions for system users may cause some packages to behave unreliably, if the program relies on the default setting. See also DIR_MODE.

SYS_NAME_REGEX
    System user- and groupnames are checked against this regular expression. If the name doesn't match this regexp, system user and group creation in adduser is refused unless --allow-bad-names is set. With --allow-bad-names set, weaker checks are performed. Defaults to the most conservative ^[a-zA-Z_][a-zA-Z0-9_-]*\$?$. See NAME_REGEX, above, and Valid names, below, for more information.

UID_POOL  and  GID_POOL
    specify a file or a directory containing UID and GID pool files. See UID AND GID POOLS in the NOTES section. Both default to empty.

USERGROUPS
    Specify whether each created non-system user will be given their own group to use. Defaults to yes.

USERS_GID  and  USERS_GROUP
    Defines the groupname or GID of the group all newly-created non-system users are placed into. If USERGROUPS is yes, the group will be added as a supplementary group; if USERGROUPS is no,, it will be the primary group. If you don't want all your users to be in one group, set USERGROUPS=yes, leave USERS_GROUP empty and set USERS_GID to "-1". USERS_GROUP defaults to users, which has GID 100 on all Debian systems since it's defined statically by the base-passwd package. It is a configuration error to define both variables even if the values are consistent.

NOTES

  UID AND GID POOLS
Some installations desire that a non-system account gets preconfigured properties when it is generated. Commonly, the local admin wants to make sure that even without using a directory service, an account or a group with a certain name has the same numeric UID/GID on all systems where it exists.

To enable this feature, define configuration variables UID_POOL (for user accounts) and/or GID_POOL (for groups) in /etc/adduser.conf and install the respective files in the configured places. The value is either a file or a directory. In the latter case all files named *.conf in that directory are considered.

The file format is similar to /etc/passwd: Text lines, fields separated by a colon. The values are username/groupname (mandatory), UID/GID (mandatory), comment field (optional, useful for user IDs only), home directory (ditto), shell (ditto).

It is possible to use the same file/directory for UID_POOL and GID_POOL. But you cannot copy lines from /etc/passwd or /etc/group since pool file lines have less fields.

If an account / group is created, adduser(8) searches in all UID/GID pool files for a line matching the name of the newly created account and uses the data found there to initialize the new account instead of using the defaults. Settings may be overridden from the command line.

In the default configuration, UID and GID values listed in the pool will be reserved and thus not be used by the normal UID and GID selection processes. This is usually what you'd want. With the RESERVE_UID_POOL and RESERVE_GID_POOL configuration options, you can switch this behavior off if you want pooled UIDs and GIDs used by regular accounts. This might cause conflicts and cause your pool UIDs and GIDs to be used by accounts that are not in the pool.

FILES
/etc/adduser.conf

SEE ALSO
deluser.conf(5), addgroup(8), adduser(8), delgroup(8), deluser(8)