Chapter 20. Using SSSD component from IdM to cache the autofs maps
The System Security Services Daemon (SSSD) is a system service to access remote service directories and authentication mechanisms. The data caching is useful in case of the slow network connection. To configure the SSSD service to cache the autofs map, follow the procedures below in this section.
20.1. Configuring autofs manually to use IdM server as an LDAP server
				Configure autofs to use IdM server as an LDAP server.
			
Procedure
- Edit the - /etc/autofs.conffile to specify the schema attributes that- autofssearches for:- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- User can write the attributes in both lower and upper cases in the - /etc/autofs.conffile.
- Optional: Specify the LDAP configuration. There are two ways to do this. The simplest is to let the automount service discover the LDAP server and locations on its own: - ldap_uri = "ldap:///dc=example,dc=com" - ldap_uri = "ldap:///dc=example,dc=com"- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - This option requires DNS to contain SRV records for the discoverable servers. - Alternatively, explicitly set which LDAP server to use and the base DN for LDAP searches: - ldap_uri = "ldap://ipa.example.com" search_base = "cn=location,cn=automount,dc=example,dc=com" - ldap_uri = "ldap://ipa.example.com" search_base = "cn=location,cn=automount,dc=example,dc=com"- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Edit the - /etc/autofs_ldap_auth.conffile so that autofs allows client authentication with the IdM LDAP server.- 
								Change authrequiredto yes.
- Set the principal to the Kerberos host principal for the IdM LDAP server, host/FQDN@REALM. The principal name is used to connect to the IdM directory as part of GSS client authentication. - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - For more information about host principal, see Using canonicalized DNS host names in IdM. - If necessary, run - klist -kto get the exact host principal information.
 
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20.2. Configuring SSSD to cache autofs maps
				The SSSD service can be used to cache autofs maps stored on an IdM server without having to configure autofs to use the IdM server at all.
			
Prerequisites
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						The sssdpackage is installed.
Procedure
- Open the SSSD configuration file: - vim /etc/sssd/sssd.conf - # vim /etc/sssd/sssd.conf- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Add the - autofsservice to the list of services handled by SSSD.- [sssd] domains = ldap services = nss,pam,autofs - [sssd] domains = ldap services = nss,pam,autofs- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Create a new - [autofs]section. You can leave this blank, because the default settings for an- autofsservice work with most infrastructures.- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - For more information, see the - sssd.confman page on your system.
- Optional: Set a search base for the - autofsentries. By default, this is the LDAP search base, but a subtree can be specified in the- ldap_autofs_search_baseparameter.- [domain/EXAMPLE] ldap_search_base = "dc=example,dc=com" ldap_autofs_search_base = "ou=automount,dc=example,dc=com" - [domain/EXAMPLE] ldap_search_base = "dc=example,dc=com" ldap_autofs_search_base = "ou=automount,dc=example,dc=com"- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Restart SSSD service: - systemctl restart sssd.service - # systemctl restart sssd.service- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Check the - /etc/nsswitch.conffile, so that SSSD is listed as a source for automount configuration:- automount: sss files - automount: sss files- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Restart - autofsservice:- systemctl restart autofs.service - # systemctl restart autofs.service- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Test the configuration by listing a user’s - /homedirectory, assuming there is a master map entry for- /home:- ls /home/userName - # ls /home/userName- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - If this does not mount the remote file system, check the - /var/log/messagesfile for errors. If necessary, increase the debug level in the- /etc/sysconfig/autofsfile by setting the- loggingparameter to- debug.