Este conteúdo não está disponível no idioma selecionado.
Chapter 5. Using automount in IdM
Automount is a way to manage, organize, and access directories across multiple systems. Automount automatically mounts a directory whenever access to it is requested. This works well within an Identity Management (IdM) domain as it allows you to share directories on clients within the domain easily.
The example uses the following scenario:
- nfs-server.idm.example.com is the fully-qualified domain name (FQDN) of a Network File System (NFS) server.
For the sake of simplicity, nfs-server.idm.example.com is an IdM client that provides the maps for the raleigh automount location.
NoteAn automount location is a unique set of NFS maps. Ideally, these maps are all located in the same geographical region so that, for example, the clients can benefit from fast connections, but this is not mandatory.
- The NFS server exports the /exports/project directory as read-write.
- Any IdM user belonging to the developers group can access the contents of the exported directory as /devel/project/ on any IdM client that uses the raleigh automount location.
- idm-client.idm.example.com is an IdM client that uses the raleigh automount location.
If you want to use a Samba server instead of an NFS server to provide the shares for IdM clients, see the How do I configure kerberized CIFS mounts with Autofs in an IPA environment? KCS solution.
5.1. Autofs and automount in IdM
The autofs
service automates the mounting of directories, as needed, by directing the automount
daemon to mount directories when they are accessed. In addition, after a period of inactivity, autofs
directs automount
to unmount auto-mounted directories. Unlike static mounting, on-demand mounting saves system resources.
- Automount maps
On a system that utilizes
autofs
, theautomount
configuration is stored in several different files. The primaryautomount
configuration file is/etc/auto.master
, which contains the master mapping ofautomount
mount points, and their associated resources, on a system. This mapping is known as automount maps.The
/etc/auto.master
configuration file contains the master map. It can contain references to other maps. These maps can either be direct or indirect. Direct maps use absolute path names for their mount points, while indirect maps use relative path names.- Automount configuration in IdM
While
automount
typically retrieves its map data from the local/etc/auto.master
and associated files, it can also retrieve map data from other sources. One common source is an LDAP server. In the context of Identity Management (IdM), this is a 389 Directory Server.If a system that uses
autofs
is a client in an IdM domain, theautomount
configuration is not stored in local configuration files. Instead, theautofs
configuration, such as maps, locations, and keys, is stored as LDAP entries in the IdM directory. For example, for theidm.example.com
IdM domain, the default master map is stored as follows:dn: automountmapname=auto.master,cn=default,cn=automount,dc=idm,dc=example,dc=com objectClass: automountMap objectClass: top automountMapName: auto.master
Additional resources
5.2. Setting up an NFS server with Kerberos in a Red Hat Identity Management domain
If you use Red Hat Identity Management (IdM), you can join your NFS server to the IdM domain. This enables you to centrally manage users and groups and to use Kerberos for authentication, integrity protection, and traffic encryption.
Prerequisites
- The NFS server is enrolled in a Red Hat Identity Management (IdM) domain.
- The NFS server is running and configured.
Procedure
Obtain a kerberos ticket as an IdM administrator:
# kinit admin
Create a
nfs/<FQDN>
service principal:# ipa service-add nfs/nfs_server.idm.example.com
Retrieve the
nfs
service principal from IdM, and store it in the/etc/krb5.keytab
file:# ipa-getkeytab -s idm_server.idm.example.com -p nfs/nfs_server.idm.example.com -k /etc/krb5.keytab
Optional: Display the principals in the
/etc/krb5.keytab
file:# klist -k /etc/krb5.keytab Keytab name: FILE:/etc/krb5.keytab KVNO Principal ---- -------------------------------------------------------------------------- 1 nfs/nfs_server.idm.example.com@IDM.EXAMPLE.COM 1 nfs/nfs_server.idm.example.com@IDM.EXAMPLE.COM 1 nfs/nfs_server.idm.example.com@IDM.EXAMPLE.COM 1 nfs/nfs_server.idm.example.com@IDM.EXAMPLE.COM 7 host/nfs_server.idm.example.com@IDM.EXAMPLE.COM 7 host/nfs_server.idm.example.com@IDM.EXAMPLE.COM 7 host/nfs_server.idm.example.com@IDM.EXAMPLE.COM 7 host/nfs_server.idm.example.com@IDM.EXAMPLE.COM
By default, the IdM client adds the host principal to the
/etc/krb5.keytab
file when you join the host to the IdM domain. If the host principal is missing, use theipa-getkeytab -s idm_server.idm.example.com -p host/nfs_server.idm.example.com -k /etc/krb5.keytab
command to add it.Use the
ipa-client-automount
utility to configure mapping of IdM IDs:# ipa-client-automount Searching for IPA server... IPA server: DNS discovery Location: default Continue to configure the system with these values? [no]: yes Configured /etc/idmapd.conf Restarting sssd, waiting for it to become available. Started autofs
Update your
/etc/exports
file, and add the Kerberos security method to the client options. For example:/nfs/projects/ 192.0.2.0/24(rw,sec=krb5i)
If you want that your clients can select from multiple security methods, specify them separated by colons:
/nfs/projects/ 192.0.2.0/24(rw,sec=krb5:krb5i:krb5p)
Reload the exported file systems:
# exportfs -r
5.3. Configuring automount locations and maps in IdM using the IdM CLI
A location is a set of maps, which are all stored in auto.master
. A location can store multiple maps. The location entry only works as a container for map entries; it is not an automount configuration in and of itself.
As a system administrator in Identity Management (IdM), you can configure automount locations and maps in IdM so that IdM users in the specified locations can access shares exported by an NFS server by navigating to specific mount points on their hosts. Both the exported NFS server directory and the mount points are specified in the maps. The example describes how to configure the raleigh location and a map that mounts the nfs-server.idm.example.com:/exports/project share on the /devel/ mount point on the IdM client as a read-write directory.
Prerequisites
- You are logged in as an IdM administrator on any IdM-enrolled host.
Procedure
Create the raleigh automount location:
$ ipa automountlocation-add raleigh ---------------------------------- Added automount location "raleigh" ---------------------------------- Location: raleigh
Create an auto.devel automount map in the raleigh location:
$ ipa automountmap-add raleigh auto.devel -------------------------------- Added automount map "auto.devel" -------------------------------- Map: auto.devel
Add the keys and mount information for the exports/ share:
Add the key and mount information for the auto.devel map:
$ ipa automountkey-add raleigh auto.devel --key='*' --info='-sec=krb5p,vers=4 nfs-server.idm.example.com:/exports/&' ----------------------- Added automount key "*" ----------------------- Key: * Mount information: -sec=krb5p,vers=4 nfs-server.idm.example.com:/exports/&
Add the key and mount information for the auto.master map:
$ ipa automountkey-add raleigh auto.master --key=/devel --info=auto.devel ---------------------------- Added automount key "/devel" ---------------------------- Key: /devel Mount information: auto.devel
5.4. Configuring automount on an IdM client
As an Identity Management (IdM) system administrator, you can configure automount services on an IdM client so that NFS shares configured for a location to which the client has been added are accessible to an IdM user automatically when the user logs in to the client. The example describes how to configure an IdM client to use automount services that are available in the raleigh location.
Prerequisites
-
You have
root
access to the IdM client. - You are logged in as IdM administrator.
- The automount location exists. The example location is raleigh.
Procedure
On the IdM client, enter the
ipa-client-automount
command and specify the location. Use the-U
option to run the script unattended:# ipa-client-automount --location raleigh -U
Stop the autofs service, clear the SSSD cache, and start the autofs service to load the new configuration settings:
# systemctl stop autofs ; sss_cache -E ; systemctl start autofs