NIS Ubuntu
NIS or Network Information Services is a simple - and insecure - way of making Single Sign On in a cluster of UNIX/Linux machines. Very useful in a closed network.
Originally NIS was called YP - Yellow Pages - and the acronyms YP and NIS are used.
There are up to three roles in a NIS installation
- Master server
- The master server - shares files to slaves and clients. For example the passwd and group file
- Slave server(s)
- Maintain copies of the Master Server shared files. Provides redundancy and load balancing
- Clients
- Use the shared files - for example for single sign on. Users added on the master server
Contents
Installation of the master server
Add the following line to /etc/hosts.allow. (In this case master,slaves and clients lives in the 10.222.0.0/24 network)
portmap ypserv ypbind: 10.222.0.0/255.255.255.0
Install NIS. You will be asked to enter the domain name. The domain name is not the DNS domain name - but a unique name for the the cluster of machines sharing the same information. (I use the DNS domain name - one less thing to remember)
apt-get install portmap nis
- Edit /etc/default/nis and set the NISSERVER line to NISSERVER = master
- Edit /etc/yp.conf and add a server line of the form: (Note my domain-name is c1.local)
domain c1.local server 127.0.0.1
- Edit /etc/ypserv.securenets remove the 0.0.0.0 line - insecure - and add your net/nets
Adding a user=
When adding a user with adduser it's necessary to rebuild the NIS maps
root@head:~# <input>make -C /var/yp</input>
make: Går til katalog '/var/yp'
make[1]: Går til katalog '/var/yp/c1.local'
Updating passwd.byname...
Updating passwd.byuid...
Updating netid.byname...
Updating shadow.byname...
make[1]: Forlader katalog '/var/yp/c1.local'
make: Forlader katalog '/var/yp'
Installation on the clients
Install the software
sudo apt-get install portmap nis
run the following commands. Remember to change the IP address of the NIS_SERVER_IP to your NIS servers IP address.
echo "portmap : <notice>NIS_SERVER_IP</notice> >> /etc/hosts.allow
echo "+::::::" >> /etc/passwd
echo "+:::" >> /etc/group
echo "+::::::::" >> /etc/shadow
echo "ypserver <notice>NIS_SERVER_IP</notice> >> /etc/yp.conf
/etc/init.d/nis restart
Test with
yptest