Ubuntu - etc - resolv.conf - Opting-out of netconfig

netconfig is often found on openSUSE, SUSE, and derivative distributions.

You can disable netconfig’s handling of /etc/resolv.conf by disabling the NETCONFIG_DNS_POLICY option in /etc/sysconfig/network/config to an empty string as shown below.

/etc/sysconfig/network/config
NETCONFIG_DNS_POLICY=""

Afterward, you should delete the netconfig-generated resolv.conf file, and reboot the system.

rm /etc/resolv.conf
reboot

See Recreating /etc/resolv.conf.