The

libnss-ldap

package handles fetching account information from LDAP. Also make sure that

nscd

is installed, otherwise bad things may happen.

To tell

libnss-ldap

where to look, you need to edit the

/etc/libnss-ldap.conf

. At the very least, you'll need to give the host and base (

dc=tardis,dc=ed,dc=ac,dc=uk

).

To tell libc to use

libnss-ldap

, you need to amend the appropriate lines in

/etc/nsswitch.conf

:

passwd:         files ldap 
group:          files ldap
shadow:         files ldap

The other databases are best left alone; we don't bother putting host information or such like in LDAP because we don't see much benefit.

The

getent

program is useful for testing.

The

libpam-ldap

package is used for authentication against LDAP. You need to configure

/etc/pam_ldap.conf

along the same lines as

/etc/libnss_ldap.conf

. A typical example is:

host piper
base dc=tardis,dc=ed,dc=ac,dc=uk
rootbinddn cn=admin,dc=tardis,dc=ed,dc=ac,dc=uk
ldap_version 3

# NSS lookups need to be restricted to the appropriate parts of the tree.
# If other lookups are added to /etc/nsswitch.conf, they need to be put
# here too.
nss_base_passwd ou=People,dc=tardis,dc=ed,dc=ac,dc=uk
nss_base_group   ou=Group,dc=tardis,dc=ed,dc=ac,dc=uk
nss_base_shadow ou=People,dc=tardis,dc=ed,dc=ac,dc=uk

# Use funky generic LDAP password changing.
pam_password exop

PAM needs to be told to use

libpam-ldap

, as well as the normal authentication for

root

. Canonical

/etc/pam.d/common-auth

:

# ** Use trick from /usr/share/doc/libpam-ldap/README.Debian
#
auth    [success=1 default=ignore]      pam_unix.so nullok_secure
auth    required                        pam_ldap.so use_first_pass
auth    required                        pam_permit.so

Note the

use_first_pass

option. Without it logins will ask for a password for pam_unix, then one for pam_ldap, and so on, causing every other attempt to enter your password to fail even when you get it right. You need to set up

/etc/pam.d/common-account

in the same way.

This guide was tested with Fedora Server 21 (on valiant).

• Run `authconfig-tui` (if not installed, `yum install -y authconfig`
• Check 'Use LDAP' and 'Use LDAP Authentication'. Make sure 'Local authorization is sufficient' is also checked.
• Leave `Use TLS` unchecked.
• Set server to `ldap://ldap/`
• Set Base DN to `dc=tardis,dc=ed,dc=ac,dc=uk`

Easy!