realmd.conf

realmd.conf — Tweak behavior of realmd

Configuration File

realmd can be tweaked by network administrators to act in specific ways. This is done by placing settings in a /etc/realmd.conf. This file does not exist by default. The syntax of this file is the same as an INI file or Desktop Entry file.

In general, settings in this file only apply at the point of joining a domain or realm. Once the realm has been setup the settings have no effect. You may choose to configure SSSD or Winbind directly.

Only specify the settings you wish to override in the /etc/realmd.conf file. Settings not specified will be loaded from their packaged defaults. Only override the settings below. You may find other settings if you look through the realmd source code. However these are not guaranteed to remain stable.

There are various sections in the config file. Some sections are global topic sections, and are listed below. Other sections are specific to a given realm. These realm specific sections should always contain the domain name in lower case as their section header.

Examples of each setting is found below, including the header of the section it should be placed in. However in the resulting file only include each section once, and combine the various section setting together as lines underneath the section. For example

[users]
default-home = /home/%U
default-shell = /bin/bash

active-directory

These options should go in an [active-directory] section of the /etc/realmd.conf file. Only specify the settings you wish to override.

default-client

Specify the default-client setting in order to control which client software is the preferred default for use with Active Directory.

[active-directory]
default-client = sssd
# default-client = winbind

The default setting for this is sssd which uses SSSD as the Active Directory client. You can also specify winbind to use Samba Winbind.

Some callers of realmd such as the realm command line tool allow specifying which client software should be used. Others, such as GNOME Control Center, simplify choose the default.

You can verify the preferred default client softawre by running the following command. The realm with the preferred client software will be listed first.

$ realm discover domain.example.com
domain.example.com
  configured: no
  server-software: active-directory
  client-software: sssd
  type: kerberos
  realm-name: AD.THEWALTER.LAN
  domain-name: ad.thewalter.lan
domain.example.com
  configured: no
  server-software: active-directory
  client-software: winbind
  type: kerberos
  realm-name: AD.THEWALTER.LAN
  domain-name: ad.thewalter.lan

os-name

(see below)

os-version

Specify the os-name and/or os-version settings to control the values that are placed in the computer account operatingSystem and operatingSystemVersion attributes.

This is an Active Directory specific option.

[active-directory]
os-name = Gentoo Linux
os-version = 9.9.9.9.9

service

These options should go in an [service] section of the /etc/realmd.conf file. Only specify the settings you wish to override.

automatic-install

Set this to no to disable automatic installation of packages via package-kit.

[service]
automatic-install = no
# automatic-install = yes

users

These options should go in an [users] section of the /etc/realmd.conf file. Only specify the settings you wish to override.

default-home

Specify the default-home setting in order to control how to set the home directory for accounts that have no home directory explicitly set.

[users]
default-home = /home/%D/%U
# default-home = /nfs/home/%D-%U

The default setting for this is /home/%D/%U. The %D format is replaced by the domain name. The %U format is replaced by the user name.

You can verify the home directory for a user by running the following command.

$ getent passwd 'DOMAIN/User'
DOMAIN\user:*:13445:13446:Name:/home/DOMAIN/user:/bin/bash

Note that in the case of IPA domains, most users already have a home directory configured in the domain. Therefore this configuration setting may rarely show through.

default-shell

Specify the default-shell setting in order to control how to set the Unix shell for accounts that have no shell explicitly set.

[users]
default-shell = /bin/bash
# default-shell = /bin/sh

The default setting for this is /bin/bash shell. The shell should be a valid shell if you expect the domain users be able to log in. For example it should exist in the /etc/shells file.

You can verify the shell for a user by running the following command.

$ getent passwd 'DOMAIN/User'
DOMAIN\user:*:13445:13446:Name:/home/DOMAIN/user:/bin/bash

Note that in the case of IPA domains, most users already have a shell configured in the domain. Therefore this configuration setting may rarely show through.

Realm specific settings

These options should go in an section with the same name as the realm in the /etc/realmd.conf file. For example for the domain.example.com domain the section would be called [domain.example.com]. To figure out the canonical name for a realm use the realm command:

$ realm discover --name DOMAIN.example.com
domain.example.com
...

Only specify the settings you wish to override.

computer-ou

Specify this option to create directory computer accounts in a location other than the default. This currently only works with Active Directory domains.

[domain.example.com]
computer-ou = OU=Linux Computers,DC=domain,DC=example,DC=com
# computer-ou = OU=Linux Computers,

Specify the OU as an LDAP DN. It can be relative to the Root DSE, or a complete LDAP DN. Obviously the OU must exist in the directory.

It is also possible to use the --computer-ou argument of the realm command to create a computer account at a specific OU.

user-prinicpal

Set the user-prinicpal to yes to create userPrincipalName attributes for the computer account in the realm, in the form host/computer@REALM

[domain.example.com]
user-principal = yes

automatic-id-mapping

This option is on by default for Active Directory realms. Turn it off to use UID and GID information stored in the directory (as-per RFC2307) rather than automatically generating UID and GID numbers.

This option only makes sense for Active Directory realms.

[domain.example.com]
automatic-id-mapping = no
# automatic-id-mapping = yes

manage-system

This option is on by default. Normally joining a realm affects many aspects of the configuration and management of the system. Turning this off limits the interaction with the realm or domain to authentication and identity.

[domain.example.com]
manage-system = no
# manage-system = yes

When this option is turned on realmd defaults to using domain policy to control who can log into this machine. Further adjustments to login policy can be made with the realm permit command.

fully-qualified-names

This option is on by default. If turned off then realm user and group names are not qualified their name. This may cause them to conflict with local user and group names.

[domain.example.com]
fully-qualified-names = no
# fully-qualified-names = yes