From baa555616f0cc40cd5023c3a9f70ee87e4ef13ec Mon Sep 17 00:00:00 2001
From: Rabi Mishra <ramishra@redhat.com>
Date: Thu, 3 Dec 2020 12:58:05 +0530
Subject: [PATCH] Stop NetworkManager from updating resolv.conf

cloud-init creates /etc/NetworkManager/conf.d/99-cloud-init.conf,
for NetworkManager to not update resolv.conf. However, subsequent
update of NetworkManager seems to remove that file as there is no
config(noreplace) directive for it. So after an update/upgrade of
overcloud nodes, reboot would cleanup the dns entries.

cloud-init do configuration only one time during first instance
boot. So this would ensure resolv.conf is not touched during
subsequent reboots.

Change-Id: I989e3f1d14fd33e97933032111cf48166dc5f50c
(cherry picked from commit 6881079d12a9fb2cf752a5f56116c1b4d3a7b75d)
---
 .../roles/tripleo_bootstrap/tasks/main.yml    | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tripleo_ansible/roles/tripleo_bootstrap/tasks/main.yml b/tripleo_ansible/roles/tripleo_bootstrap/tasks/main.yml
index aaa5b5a2a..2e5c697a2 100644
--- a/tripleo_ansible/roles/tripleo_bootstrap/tasks/main.yml
+++ b/tripleo_ansible/roles/tripleo_bootstrap/tasks/main.yml
@@ -78,6 +78,25 @@
         name: "{{ tripleo_bootstrap_network_service }}"
         enabled: true
 
+- name: Stop NetworkManager from updating resolv.conf
+  become: true
+  when: tripleo_bootstrap_network_service == 'NetworkManager'
+  block:
+    - name: Set 'dns=none' in /etc/NetworkManager/NetworkManager.conf
+      ini_file:
+        path: /etc/NetworkManager/NetworkManager.conf
+        state: present
+        no_extra_spaces: true
+        section: main
+        option: dns
+        value: none
+        backup: true
+
+    - name: Reload NetworkManager
+      service:
+        name: NetworkManager
+        state: reloaded
+
 - name: Symlink puppet modules under /etc/puppet/modules
   become: true
   shell: >-