centos resolv.conf keeps getting overwritten

So if ever resolv.conf keeps getting overwritten when you boot linux you can tear your hair out trying to
work out why various web sites will tell you its NetworkManager (as does the file) or dhcpd or netctl.

Having ruled out all those, checked all sorts of boot scripts and even tried to use audit to find out what is changing the file check for /etc/resolv.conf.save. If it exists it will get copied to /etc/resolv.conf when the server boots.

remove /etc/resolv.conf.save and all should be well.