How to setup DNS cluster on CWP 3 – Add additional Nameservers

Where there is the need to additional nameservers to an existing cluster, the following needs to be met:

If the above are met, then proceed to the following steps to configure an additional nameserver

step 1: create the file /root/dns_sync_slave2.conf and add the following content

USERNAME="slave"
SERVER="192.168.78.129"
SSHPORT="22"
SOURCESYNCLOCATION="/var/named/slave"
CHECKMAINDNS="centos-webpanel.com"
LOCALSYNCLOCATION="/var/named/slave"
LOCALCONFFILE="/etc/named/slave_additional.conf"

The keyword are explained below:
USERNAME = the user created on the DNS manager
SERVER = IP of DNS Manager.
SSHPORT = SSH-Port of Slave DNS Server & Manager.
SOURCESYNCLOCATION = Location of DNS zone files on Slave DNS Server & Manager.
CHECKMAINDNS = This is a domain used for testing Slave DNS Server & Manager, it can be any domain and doesn’t need to be on the server.
LOCALSYNCLOCATION = Location for DNS zone files on this local server.
LOCALCONFFILE = Configuration files which contains the list of all zone files on this local server.

step 2: Setup cron how often you want to check for changes
crontab -e

add the following:

* * * * * sh /scripts/dns_sync_slave2 

Note: On servers with many clients and domains 100+ we recommend 5min cron. For servers with 1000+ you can go even with every 1-2 minutes.

step 3: In file /etc/named.conf after options{} where other include lines are specifed add:

include "/etc/named/slave_additional.conf";

step 4: Prepare config files

touch /etc/named/slave_additional.conf
chown named.named /etc/named/slave_additional.conf

step 5: Generate a public key and copy to the DNS manager
CWP.Admin –> Server settings –> SSH Key Generator

Copy the key specified under the heading You Public Key from: /root/.ssh/id_rsa.pub

mkdir /home/slave/.ssh
chown -R slave.slave /home/slave/.ssh
chmod 600 /home/slave/.ssh/authorized_keys
chmod 700 /home/slave/.ssh/

nano /home/slave/.ssh/authorized_keys

Note: Other nameservers you add to the DNS manager, you copy the public key to this file only

step 7: On DNS manager, enable shell for the slave user
By default, acount created on CWP has bash shell disabled. for the addditional nameserver to be able to sync the zone files from the DNS manager, the bash shell for the slave user needs to be enabled.

chsh -s /bin/bash slave

step 8: Testing passwordless login
You can now test ssh connection from the additional nameserver to DNS Server

ssh slave@SERVER-IP -p SSH-PORT

If your connection goes ok without asking for the password then the additional server is ok and ready to receive zone files.

References
CWP wiki