Through this blog, I am explaining how to configure autofs maps in LDAP using different schemas supported by autofs in Red Hat Enterprise Linux 5. In this blog, I am not explaining details of how to configure LDAP server. It's assumed that you have an LDAP server in your environment which is already working perfectly, anonymous read access is allowed for the autofs maps and autofs clients are allowed to contact port 389 of the ldap server. Different LDAP servers provide different interfaces to manage databases. So explaining how to add the data to ldap database and how to manage them are outside the scope of this doc.
It's also assumed that every client in the network is already configured as a client of the ldap server to take user Information from the LDAP server via authconfig-tui. If no, please configure all clients as below.
Run "authconfig-tui". In the "User Information" section, select "Use LDAP" -> Next -> Type in the server name as ldap://ip-of-ldap-server-> Enter "dc=example,dc=com" as the "Base DN". Click "ok".
It's also assumed that every client in the network is already configured as a client of the ldap server to take user Information from the LDAP server via authconfig-tui. If no, please configure all clients as below.
Run "authconfig-tui". In the "User Information" section, select "Use LDAP" -> Next -> Type in the server name as ldap://ip-of-ldap-server-> Enter "dc=example,dc=com" as the "Base DN". Click "ok".
Currently there are three different schemas supported by autofs. I would take the below scenario as an example to explain these three schemas. This scenario includes examples for both direct mounts and indirect mounts. If you don't know what is the difference between direct and indirect mounts, please stop here, search the web and get a thorough understanding and come back.
- /direct (nfs share) from a remote server need to be auto mounted on /diret-mnt on the client whenever a user tries to access /direct-mnt.
- /isos/debian-40r7-i386-netinst.iso (kept locally on every client) should be auto mounted on /debian whenever a user tries to access /debian.
- /homedirs/$username from a remote server need to be auto mounted on /home/$username whenever a user attempts to log in to the client.
- If user x tries to access /projects/x, /projects/x from the remote system should be auto mounted.
We would configure #1 and #2 using direct mount and #3 and #4 using indirect mount. If ldap is not used, the equivalent local configuration file (/etc/auto.master and other mapped files) would look like as below.
/etc/auto.master
+auto.master
/- /etc/auto.direct
/home /etc/auto.home
/projects /etc/auto.project
/etc/auto.direct
/direct-mnt -fstype=nfs,rw ip-of-nfs-server:/direct
/debian -fstype=iso9660,ro,loop :/iso/debian-40r7-i386-netinst.iso
/etc/auto.home
* -fstype=nfs,rw ip-of-nfs-server:/homedirs/&
/etc/auto.project
x -fstype=nfs,rw ip-of-nfs-server:/projects/x
Now we are exploring how we can define all these maps in ldap server and configure the autofs in client to read the maps from ldap server instead of local files. The only thing needed locally is the below entry in /etc/auto.master which is there in all RHEL5 systems by default..
+auto.master
Schema I
The LDIF file to populate the above maps to ldap server would look like as below. The ldap suffix used in my example is dc=example,dc=com which is already defined in the ldap server.
Below is the definition of the schema for LDAPv3 servers.
attributetype ( 1.3.6.1.1.1.1.26 NAME 'nisMapName'
SUP name )
attributetype ( 1.3.6.1.1.1.1.27 NAME 'nisMapEntry'
EQUALITY caseExactIA5Match
SUBSTR caseExactIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{1024} SINGLE-VALUE )
objectclass ( 1.3.6.1.1.1.2.9 NAME 'nisMap'
DESC 'A generic abstraction of a NIS map'
SUP top STRUCTURAL
MUST nisMapName
MAY description )
objectclass ( 1.3.6.1.1.1.2.10 NAME 'nisObject'
DESC 'An entry in a NIS map'
SUP top STRUCTURAL
MUST ( cn $ nisMapEntry $ nisMapName )
MAY description )
Below is the LDIF file which defines the ldap maps for autofs for the above mentioned example.
#defining auto.master
dn: nisMapName=auto.master,dc=example,dc=com
objectClass: top
objectClass: nisMap
nisMapName: auto.master
#Defining all those required for auto.direct (1 & 2)
dn: cn=/-,nisMapName=auto.master,dc=example,dc=com
objectClass: nisObject
cn: /-
nisMapName: auto.master
nisMapEntry: auto.direct
dn: nisMapName=auto.direct,dc=example,dc=com
objectClass: top
objectClass: nisMap
nisMapName: auto.direct
dn: cn=/direct-mnt,nisMapName=auto.direct,dc=example,dc=com
objectClass: nisObject
cn: /direct-mnt
nisMapName: auto.direct
nisMapEntry: -fstype=nfs,rw ip-of-nfs-server:/direct
dn: cn=/debian,nisMapName=auto.direct,dc=example,dc=com
objectClass: nisObject
cn: /debian
nisMapName: auto.direct
nisMapEntry: -fstype=iso9660,ro,loop :/iso/debian-40r7-i386-netinst.iso
#Defining all those required for auto.home (3)
dn: cn=/home,nisMapName=auto.master,dc=example,dc=com
objectClass: nisObject
cn: /home
nisMapName: auto.master
nisMapEntry: auto.home
dn: nisMapName=auto.home,dc=example,dc=com
objectClass: top
objectClass: nisMap
nisMapName: auto.home
dn: cn=/,nisMapName=auto.home,dc=example,dc=com
objectClass: nisObject
cn: /
nisMapName: auto.home
nisMapEntry: -fstype=nfs,rw ip-of-nfs-server:/homedirs/&
#Defining all those required for auto.project (4)
dn: cn=/projects,nisMapName=auto.master,dc=example,dc=com
objectClass: nisObject
cn: /projects
nisMapName: auto.master
nisMapEntry: auto.project
dn: nisMapName=auto.project,dc=example,dc=com
objectClass: top
objectClass: nisMap
nisMapName: auto.project
dn: cn=x,nisMapName=auto.project,dc=example,dc=com
objectClass: nisObject
cn: x
nisMapName: auto.project
nisMapEntry: -fstype=nfs,rw ip-of-nfs-server:/projects/x
- Populate the ldap databae with the above ldif file. Please refer the respective ldap server docs to know more on how to do that.
- On the client, edit /etc/sysconfig/autofs and uncomment the below lines.
MAP_OBJECT_CLASS="nisMap"
ENTRY_OBJECT_CLASS="nisObject"
MAP_ATTRIBUTE="nisMapName"
ENTRY_ATTRIBUTE="cn"
VALUE_ATTRIBUTE="nisMapEntry"
- Restart autofs and verify everything is working as expected.
Schema II
Below is the definition of the schema for LDAPv3 servers.
attributetype ( 1.3.6.1.1.1.1.25 NAME 'automountInformation'
DESC 'Information used by the autofs automounter'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 SINGLE-VALUE )
objectclass ( 1.3.6.1.1.1.1.13 NAME 'automount' SUP top STRUCTURAL
DESC 'An entry in an automounter map'
MUST ( cn $ automountInformation )
MAY ( description ) )
objectclass ( 1.3.6.1.4.1.2312.4.2.2 NAME 'automountMap' SUP top STRUCTURAL
DESC 'An group of related automount objects'
MUST ( ou ) )
Below is the LDIF file which defines the ldap maps for autofs for the above mentioned example.
#Defines auto.master
dn: ou=auto.master,dc=example,dc=com
objectClass: top
objectClass: automountMap
ou: auto.master
#Defining all those required for auto.direct (1 & 2)
dn: cn=/-,ou=auto.master,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /-
automountInformation: auto.direct
dn: ou=auto.direct,dc=example,dc=com
objectClass: top
objectClass: automountMap
ou: auto.direct
dn: cn=/direct-mnt,ou=auto.direct,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /direct-mnt
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/direct
dn: cn=/debian,ou=auto.direct,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /debian
automountInformation: -fstype=iso9660,ro,loop :/iso/debian-40r7-i386-netinst.iso
#Defining all those required for auto.home (3)
dn: cn=/home,ou=auto.master,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /home
automountInformation: auto.home
dn: ou=auto.home,dc=example,dc=com
objectClass: top
objectClass: automountMap
ou: auto.home
dn: cn=/,ou=auto.home,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/homedirs/&
#Defining all those required for auto.project (4)
dn: cn=/projects,ou=auto.master,dc=example,dc=com
objectClass: top
objectClass: automount
cn: /projects
automountInformation: auto.project
dn: ou=auto.project,dc=example,dc=com
objectClass: top
objectClass: automountMap
ou: auto.project
dn: cn=x,ou=auto.project,dc=example,dc=com
objectClass: top
objectClass: automount
cn: x
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/projects/x
- Populate the ldap databae with the above ldif file. Please refer the respective ldap server docs to know more on how to do that.
- On the client, edit /etc/sysconfig/autofs and uncomment the below lines.
MAP_OBJECT_CLASS="automountMap"
ENTRY_OBJECT_CLASS="automount"
MAP_ATTRIBUTE="ou"
ENTRY_ATTRIBUTE="cn"
VALUE_ATTRIBUTE="automountInformation"
- Restart autofs and verify everything is working as expected.
Schema III
Below is the definition of the schema for LDAPv3 servers.
attributetype ( 1.3.6.1.1.1.1.31 NAME 'automountMapName'
DESC 'automount Map Name'
EQUALITY caseExactIA5Match
SUBSTR caseExactIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 SINGLE-VALUE )
attributetype ( 1.3.6.1.1.1.1.32 NAME 'automountKey'
DESC 'Automount Key value'
EQUALITY caseExactIA5Match
SUBSTR caseExactIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 SINGLE-VALUE )
attributetype ( 1.3.6.1.1.1.1.33 NAME 'automountInformation'
DESC 'Automount information'
EQUALITY caseExactIA5Match
SUBSTR caseExactIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 SINGLE-VALUE )
objectclass ( 1.3.6.1.1.1.2.16 NAME 'automountMap' SUP top STRUCTURAL
MUST ( automountMapName )
MAY description )
objectclass ( 1.3.6.1.1.1.2.17 NAME 'automount' SUP top STRUCTURAL
DESC 'Automount information'
MUST ( automountKey $ automountInformation )
MAY description )
Below is the LDIF file which defines the ldap maps for autofs for the above mentioned example.
#Defines auto.master
dn: automountMapName=auto.master,dc=example,dc=com
automountMapName: auto.master
objectClass: top
objectClass: automountMap
#Defining all those required for auto.direct (1 & 2)
dn: automountKey=/-,automountMapName=auto.master,dc=example,dc=com
objectClass: automount
automountKey: /-
automountInformation: auto.direct
dn: automountMapName=auto.direct,dc=example,dc=com
automountMapName: auto.direct
objectClass: top
objectClass: automountMap
dn: automountKey=/direct-mnt,automountMapName=auto.direct,dc=example,dc=com
automountKey: /direct-mnt
objectClass: automount
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/direct
dn: automountKey=/debian,automountMapName=auto.direct,dc=example,dc=com
automountKey: /debian
objectClass: automount
automountInformation: -fstype=iso9660,ro,loop :/iso/debian-40r7-i386-netinst.iso
#Defining all those required for auto.home (3)
dn: automountKey=/home,automountMapName=auto.master,dc=example,dc=com
objectClass: automount
automountKey: /home
automountInformation: auto.home
dn: automountMapName=auto.home,dc=example,dc=com
automountMapName: auto.home
objectClass: top
objectClass: automountMap
dn: automountKey=/,automountMapName=auto.home,dc=example,dc=com
automountKey: /
objectClass: automount
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/homedirs/&
#Defining all those required for auto.project (4)
dn: automountKey=/projects,automountMapName=auto.master,dc=example,dc=com
objectClass: automount
automountKey: /projects
automountInformation: auto.project
dn: automountMapName=auto.project,dc=example,dc=com
automountMapName: auto.project
objectClass: top
objectClass: automountMap
dn: automountKey=x,automountMapName=auto.project,dc=example,dc=com
automountKey: x
objectClass: automount
automountInformation: -fstype=nfs,rw ip-of-nfs-server:/projects/x
- Populate the ldap databae with the above ldif file. Please refer the respective ldap server docs to know more on how to do that.
- On the client, edit /etc/sysconfig/autofs and uncomment the below lines.
MAP_OBJECT_CLASS="automountMap"
ENTRY_OBJECT_CLASS="automount"
MAP_ATTRIBUTE="automountMapName"
ENTRY_ATTRIBUTE="automountKey"
VALUE_ATTRIBUTE="automountInformation"
- Restart autofs and verify everything is working as expected.
Note: In all maps, please replace ip-of-nfs-server with the actual IP address of the nfs server.
