5.11. Extending DNS

Rocks provides a mechanism to put external hostnames under the DNS control of your cluster. Generally, external hosts have names served by site-wide DNS servers. However if there is no external DNS server available, you may want to use your frontend's DNS server to handle the name to IP mappings for certain non-cluster nodes.

Since the DNS configuration file is automatically generated by Rocks, you cannot add static configuration to the standard zone files in /var/named. Instead, you need to put local name mappings in the file:

/var/named/<networkname>.domain.local

And reverse mappings (IP to name) in:

/var/named/reverse.<networkname>.domain.<networkprefix>.local

Where networkname for a default Rocks installation is private and networkprefix for a default Rocks installation is 1.10. That is, the above file names would be:

For forward mapping: /var/named/private.domain.local For reverse mapping: /var/named/reverse.private.domain.1.10.local

To add the mappings in the above .local files to the running configuration, execute:

# rocks sync config

These files are in the BIND configuration format, just like the standard private.domain and reverse.private.domain files.

Your external hosts will have names in the .local cluster domain.

Errors in your local DNS files will cause the entire local cluster domain naming to fail. Proceed with caution.