OpenLDAP Everywhere Revisited
To begin configuring the Linux LDAP client, you need to install the name switch service package, nss_ldap. The Red Hat tool /usr/bin/authconfig is handy for configuring the client. Select Use LDAP and fill in the fields so that they read Server: ldapserver.foo.com and Base DN: dc=foo,dc=com. Authconfig writes to these files: /etc/ldap.conf, /etc/openldap/ldap.conf and /etc/nsswitch.conf.
Verify that /etc/nsswitch.conf has the following entries:
passwd: files ldap shadow: files ldap group: files ldap automount: files ldap
Verify that /etc/ldap.conf has these entries:
host ldapserver.foo.com base dc=foo,dc=com
Verify that /etc/openldap/ldap.conf has these entries:
HOST ldapserver.foo.com BASE dc=foo,dc=com
The user's password and group entries must be removed from the password and group files on the NFS server where home directories live. Create backups and then edit /etc/passwd, /etc/shadow, /etc/group and /etc/gshadow to remove the LDAP real people entries. In our case, /etc/passwd should have no accounts left with a UID from 1000 to 9999.
To test, log in to a Linux LDAP client using an LDAP user name. You should see the appropriate login shell and home directory for the user. To test auto.misc shares, you must access the share by name, for example:
Automount only mounts NFS shares as they are used, so the directory /share/redhat is not visible until it has been accessed.
The main purpose of using Samba and LDAP together is to achieve unified login for Microsoft Windows clients. What this means to your organization is a user will be able to log on to your network from any workstation and have access to all shared folders, files and printers.
The first step to unified login starts by configuring Samba as a primary domain controller (PDC). The full configuration details on how to set up Samba as your PDC are outside the scope of this article. Please visit the Idealx Web site for a great HOWTO (see Resources). The folks at Idealx have made great contributions to the Samba Project, and you should become familiar with their tools if you plan on using Samba.
Assuming you already have experience with setting up Samba domain controllers, this Samba configuration file should get you up and running with our directory example in the article (Listing 5). The full file is available from the Linux Journal FTP site (see Resources).
Listing 5. Excerpts from a Samba smb.conf file configured to work with the OpenLDAP directory.
[global] ... obey pam restrictions = No ldap passwd sync = Yes ldap passwd sync = Yes ... passdb backend = ldapsam:ldap://ldapserver.foo.com/ ldap admin dn = cn=Manager,dc=foo,dc=com ldap suffix = dc=foo,dc=com ldap group suffix = ou=Groups ldap user suffix = ou=People ldap machine suffix = ou=Computers ldap idmap suffix = ou=People ldap ssl = no add user script = \ /usr/local/sbin/smbldap-useradd -m "%u" ldap delete dn = Yes delete user script = \ /usr/local/sbin/smbldap-userdel "%u" add machine script = \ /usr/local/sbin/smbldap-useradd -w "%u" add group script = \ /usr/local/sbin/smbldap-groupadd -p "%g" delete group script = \ /usr/local/sbin/smbldap-groupdel "%g" add user to group script = \ /usr/local/sbin/smbldap-groupmod -m "%u" "% g" delete user from group script = \ /usr/local/sbin/smbldap-groupmod -x "% u" "%g" set primary group script = \ /usr/local/sbin/smbldap-usermod -g "%g" "%u "
The remaining piece of the puzzle involves setting up LDAP to take advantage of Samba's advancements made in the past couple of years. This should be similar to the LDAP setup above, but with updated features added in for Samba. With the new Samba 3 version, we now are able to store all Samba account information inside the LDAP directory. This is beneficial because now all the information is stored in a centralized location.
One difference in the LDAP/Samba combination setup is the additional accounts and LDAP entries that need to be populated for the two to work together. Several well-known Windows domain user accounts and domain group accounts are required for your unified login server to function. Special LDAP OU entries also are required for the server to store domain account information. Fortunately, a script called smbldap-populate is available that does all of this for you. This script is part of the Idealx smbldap-tools package that can aid you in setting up both your PDC and your Samba Enabled LDAP directory. Listing 6 is sample output of what you should see when you run the smbldap-populate script.
Fast/Flexible Linux OS Recovery
On Demand Now
In this live one-hour webinar, learn how to enhance your existing backup strategies for complete disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible full-system recovery solution for UNIX and Linux systems.
Join Linux Journal's Shawn Powers and David Huffman, President/CEO, Storix, Inc.
Free to Linux Journal readers.Register Now!
- Download "Linux Management with Red Hat Satellite: Measuring Business Impact and ROI"
- Peppermint 7 Released
- Sony Settles in Linux Battle
- Libarchive Security Flaw Discovered
- Maru OS Brings Debian to Your Phone
- Profiles and RC Files
- Snappy Moves to New Platforms
- Git 2.9 Released
- The Giant Zero, Part 0.x
- Understanding Ceph and Its Place in the Market
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide