resolv.conf on CentOS 7/RHEL 7 is NetworkManager managed

This bug was originally filed in Launchpad as [LP: #1620807](https://bugs.launchpad.net/cloud-init/+bug/1620807)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2016-09-06T20:06:49.898875+00:00

date_fix_committed = None

date_fix_released = None

id = 1620807

importance = medium

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1620807

milestone = None

owner = bregeer-ctl

owner_name = Bert JW Regeer

private = False

status = confirmed

submitter = bregeer-ctl

submitter_name = Bert JW Regeer

tags = ['centos', 'rhel']

duplicates = []

_Launchpad user **Bert JW Regeer(bregeer-ctl)** wrote on 2016-09-06T20:06:49.898875+00:00_

Related to https://bugs.launchpad.net/cloud-init/+bug/1620796 I have found that even when I have fixed cloud-init to properly write resolv.conf it gets overwritten as soon as network is started because NetworkManager takes over control:

/etc/resolv.conf

# Generated by NetworkManager
search novalocal

# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com

instead any DNS entries should be added directly to the ifcfg-eth* files that are generated, then let NM figure out what DNS resolvers it wants to add to /etc/resolv.conf.