LDAP is to Linux what Active Directory is to Windows. It's a directory-based system that allows you to centralize your user authentication. The biggest downfall with LDAP is that it's a fairly complex system, and taking advantage of it requires a significant amount of skill. But once you get that LDAP system up and running, you should be good to go. Here are a few tips that will make it easier for you to manage your mission-critical data.
1: Learn the command line
Yes, the command line. It's one of the more complicated systems you will ever come across on Linux, but when you've mastered these tools, managing LDAP becomes easier. Naturally, GUI tools are available (more on those in a minute). But having the skills to manage your LDAP data from the command line will ensure that you can tackle every possible task. Warning: Learning the command line will take time, so don't get frustrated when it seems like you just can't grasp it. Keep plowing through until you've mastered it.
2: Learn how to import user information from a file
This goes along with the previous tip. If you have to import user data into LDAP, you do NOT want to have to do it one user at a time. If you attempt this, you will be working for a very, very long time. Instead you can create one file (say, users.ldif), add all the user information you need to it, and import this information with a command like ldapadd -x -D cn=admin,dc=wallen,dc=local -W -f users.ldif. The format of each user entry looks like this:
# Willow's Entry
dn: cn=Willow Wallen,ou=people,dc=wallen,dc=local
cn: Willow Rosenberg
3: Find a good GUI
If you are uncomfortable with the command line (or just have trouble mastering LDAP from the command line), you will want a strong GUI replacement for the LDAP command tools. There are three strong candidates for this task: Webmin LDAP module, which is included in the Standard Modules package, phpLDAPadmin, and 389 Directory Server. Of these three, the easiest to use is Webmin module and the most powerful is 389 Directory Server.
4: Back up properly
One of the easiest ways to back up your LDAP data is to use slapcat. This tool will export your LDAP database into an ldif file that can then be imported back in. The basic usage of slapcat is slapcat > backup.ldif. It really is that simple. Just make sure you don't back up a running LDAP database, as slapcat does enough poking around the structure of the database to possibly cause damage.
5: Understand the LDAP directory tree
You might think this would fall under the category "Get to know LDAP," but you'd be surprised how far you can get in LDAP without really understanding the directory tree. With the help of the GUI tools, you could get LDAP up and running and set up a basic directory without knowing the structure of the directory tree at all. But it's important to understand how your information is stored so you can manage it effectively.
The basic LDAP directory tree might look something like this:
In the above example, the base DN is derived from the domain techrepublic.com. All your new records for this directory will be under dc=techrepublic,dc=com (in this example). Also note that this is the same format used by Microsoft's Active Directory, so migration is simple.
LDAP is a challenge for just about any level of experience, but you can ease this challenge by following the above tips. Of course, given the complexity of LDAP, there are plenty of other helpful tricks. If you have your own favorite tips, share them with fellow TechRepublic members.
Jack Wallen is an award-winning writer for TechRepublic and Linux.com. He’s an avid promoter of open source and the voice of The Android Expert. For more news about Jack Wallen, visit his website getjackd.net.