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LTSP Enhancements - LDAP

So you want to use LTS and have Auto Configuration, Dynamic DNS, NFS Swapping, integration with LDAP, and have a Web Based Configuration program, well Read on!

The LTSP Enhancements build upon the base LTSP distribution (we currently support version 1.90) and use LDAP to provide a centralized location to store the workstations settings. By using LDAP we are able to implement an Auto Configuration Mode which is initiated whenever the workstation detects that it is not currently configured. We have implemented a migration path that will migrate all settings in the lts.conf file to LDAP when a workstation boots that was previously configured in lts.conf.

We use the MAC Address of the workstation to store it's settings in LDAP instead of the hostname that was being given out by a static mapping in DHCP. This allows you to simplify your DHCP configuration and will alleviate many headaches when working with multiple workstations. The real beauty comes after you have configured (or migrated) all your workstations via LDAP because you can now take advantage of Dynamic DNS and NFS Swapping as we have the rc.local script configuring them if you have the correct Attributes defined.

Note: From this point on you need to be logged in as root. I am also assuming you have downloaded our latest distribution and have extracted it.

Simple Installation

To get up and running as quickly as possible, first backup your /tftpboot/lts/ltsroot directory and then extract our ltsroot2.tar.gz file into your /tftpboot/lts directory and rename it to ltsroot. Our /ltsroot2 directory already has Perl installed with working versions of the necessary modules. Modify your lts.conf file to include the necessary changes to use the features we have implemented that you want to work with and place it in /tftpboot/lts/ltsroot/etc.

Then configure your LDAP server and then restart your test workstation after configuring Dynamic DNS or NFS Swapping and watch your workstation boot into the new world of easier thin-client administration!

Manual Installation

To install and configure our LTSP Enhancements package manually, do the following:

backup your /tftpboot/lts/ltsroot directory.
Download and install the Net::LDAP, Convert::BER, and Term::ReadKey modules from CPAN. The process is usually, untar, cd into extracted directory, perl Makefile.pl, make, make test, make install
Copy the perl executables from /usr/bin to usr/bin in the lts file system. Copy the perl5 directory from /usr/lib to usr/lib in the lts file system.
Copy libdl.so.2, libm.so.6, libcrypt.so.1, libdb.so.3, libnss_files.*, ld-*, libldap.so* from /lib to lib in the lts file system. (The specific files were what perl required on our system. Yours may be different.)
Copy halt, mkswap, swapon, insmod from /sbin; rm, dd, sed from /bin to ltsbin in the lts file system.
Copy our programs from bin in the distribution tarball into /tftpboot/lts/ltsroot/ltsbin.
Copy our version of rc.local into /tftpboot/lts/ltsroot/etc.
Modify your lts.conf file and copy it into /tftpboot/lts/ltsroot/etc.
Configure Dynamic DNS, NFS Swapping, and the LDAP server and then restart a workstation to test your installation.

LDAP Server Configuration

We used OpenLDAP 1.2.9 which came with RedHat 6.2 as our LDAP Server.
After installing the server and the development rpm's, do the following:

make sure that LDAP is being started every time the server starts. Use linuxconf or chkconfig to verify the runlevels LDAP will be started/stopped in.

copy ltsp.oc.conf from our distribution to /etc/openldap.

edit /etc/openldap/slapd.conf
- add the line "include /etc/openldap/ltsp.oc.conf" to the top of the file.
- modify the suffix line to fit your needs. We use the dc=domain name, dc=domain extension style. (Ex. suffix "dc=pcxperience, dc=com")
- change the directory setting. By default it is /usr/tmp which periodically gets cleaned out and so your LDAP directory you worked so hard on may just dissapear one day! We create a directory under /var/lib and call it ldap and point the directory to that location. (Ex. directory /var/lib/ldap)
- modify the rootdn setting to reflect the same settings you used in your suffix. (Ex. If using root as the administrative account for the LDAP server you would have the following for your rootdn line: rootdn "cn=root, dc=pcxperience, dc=com" [continuing our previous example])
- now you need to indicate the password for the rootdn account. In another terminal, open /etc/passwd or /etc/shadow, if using shadow passwords, and copy the encrypted version of the password that you would like to assign to the administrative account. Insert it into the slapd.conf file as follows: rootpw {crypt}encrypted password here.
- start or restart the LDAP server by running /etc/rc.d/init.d/ldap start|restart
create the base objects and import any system wide items you want in the LDAP System. This is covered at OpenLDAP's Faq-O-Matic web site.

They use cn=manager whereas we use cn=root.

create the LTSP Organizational Unit (ou) as follows:
At a command prompt on the LDAP server type ldapadd -D "cn=root, dc=your domain name, dc=your domain extension" -W
When prompted for your password, enter the administrative password.
You should now be dropped to a blank line (the server is waiting for you to enter something).
Enter:
dn: ou=LTSP, dc=your domain name, dc=your domain extension<Enter>
ou: LTSP<Enter>
objectclass: top<Enter>
objectclass: ou<Enter>
<Enter>
You should be given a success message and then returned to an empty line prompt. Press Enter to get back to a command prompt.

edit lts.conf and add to the [Default] section these items to tell your thin-clients to use the LDAP server you just configured:
- set LDAP_HOST=IP Address of the LDAP Server
- set BIND_DN=rootdn from the /etc/openldap/slapd.conf file. (Ex. BIND_DN=cn=root,dc=pcxperience,dc=com)
- set BASE_DN=ou=LTSP,suffix, where suffix is from the /etc/openldap/slapd.conf file. (Ex. BASE_DN=ou=LTSP,dc=pcxperience,dc=com)
- After you have migrated all your workstations to LDAP via our migration code (just turn your workstations on and enter the LDAP administrative password when prompted!), you can remove all other entries from lts.conf and just leave these 3 and your system will work as though all your workstations were still in lts.conf!

Final Steps

Without our Web Based Configuration Program everything that we have implemented doesn't do you a whole lot of good as you just get a bigger headache trying to manually administer the LDAP server with the command line programs. After you install and configure the Web Based Configuration Program just surf over to Your LTSP Config Web Site (hopefully you are viewing this on your web server) and start working with your thin client configuration data!

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Copyrighted by PC Xperience, Inc., 2000.