Remove nameservers with any IP in overcloud resolv.conf workaround

Kayobe has a workaround for CentOS cloud images which contain a bogus
nameserver entry in /etc/resolv.conf. By setting
overcloud_host_image_workaround_resolv_enabled to true, the entry would
be removed. Previously we removed a specific IP address - 10.0.2.3 -
that was present in the CentOS 7 images. However, it seems that CentOS 8
images have a different IP - 192.168.122.1.

This change fixes the issue and becomes resilient to future changes by
matching any IP address. This should be fairly safe, since this
workaround is opt-in.

Change-Id: I9323a38cb2bb627ff56f5713900be00595ea8d4b
Story: 2006574
Task: 39484

ansible/group_vars/all/overcloud

@@ -22,13 +22,12 @@ disable_cloud_init: False
 ###############################################################################
 # Overcloud host image configuration.
 
-# The CentOS cloud images from 7.2 (1511) onwards have a bogus name server
-# entry in /etc/resolv.conf, 10.0.2.3. Cloud-init only appends name server
-# entries to this file, and will not remove this bogus entry. Typically this
-# leads to a delay of around 30 seconds when connecting via SSH, due to a
-# timeout in NSS. The workaround employed here is to remove this bogus entry
-# from the image using virt-customize, if it exists. See
-# https://bugs.centos.org/view.php?id=14369.
+# The CentOS cloud images have a bogus name server entry in /etc/resolv.conf,
+# 192.168.122.1. Cloud-init only appends name server entries to this file, and
+# will not remove this bogus entry. Typically this leads to a delay of around
+# 30 seconds when connecting via SSH, due to a timeout in NSS. The workaround
+# employed here is to remove this bogus entry from the image using
+# virt-customize, if it exists. See https://bugs.centos.org/view.php?id=14369.
 overcloud_host_image_workaround_resolv_enabled: True
 
 # Workaround a CentOS 7.5 bug: cloud-init 0.7.9-24 does not correctly set

ansible/overcloud-host-image-workaround-resolv.yml

 ---
-# The CentOS cloud images from 7.2 (1511) onwards have a bogus name server
-# entry in /etc/resolv.conf, 10.0.2.3. Cloud-init only appends name server
-# entries to this file, and will not remove this bogus entry. Typically this
-# leads to a delay of around 30 seconds when connecting via SSH, due to a
-# timeout in NSS. The workaround employed here is to remove this bogus entry
-# from the image using virt-customize, if it exists. See
-# https://bugs.centos.org/view.php?id=14369.
+# The CentOS cloud images have a bogus name server entry in /etc/resolv.conf,
+# 192.168.122.1. Cloud-init only appends name server entries to this file, and
+# will not remove this bogus entry. Typically this leads to a delay of around
+# 30 seconds when connecting via SSH, due to a timeout in NSS. The workaround
+# employed here is to remove this bogus entry from the image using
+# virt-customize, if it exists. See https://bugs.centos.org/view.php?id=14369.
 
 - name: Ensure the overcloud host image has bogus name server entries removed
   hosts: seed
@@ -32,5 +31,5 @@
             --connection local
             --become
             -m command
-            -a "virt-customize -a /httpboot/deployment_image.qcow2 --edit \"/etc/resolv.conf:s/^nameserver 10\.0\.2\.3\$//\""'
+            -a "virt-customize -a /httpboot/deployment_image.qcow2 --edit \"/etc/resolv.conf:s/^nameserver .*\..*\..*\..*\$//\""'
       when: overcloud_host_image_workaround_resolv_enabled | bool

etc/kayobe/overcloud.yml

@@ -19,13 +19,12 @@
 ###############################################################################
 # Overcloud host image configuration.
 
-# The CentOS cloud images from 7.2 (1511) onwards have a bogus name server
-# entry in /etc/resolv.conf, 10.0.2.3. Cloud-init only appends name server
-# entries to this file, and will not remove this bogus entry. Typically this
-# leads to a delay of around 30 seconds when connecting via SSH, due to a
-# timeout in NSS. The workaround employed here is to remove this bogus entry
-# from the image using virt-customize, if it exists. See
-# https://bugs.centos.org/view.php?id=14369.
+# The CentOS cloud images have a bogus name server entry in /etc/resolv.conf,
+# 192.168.122.1. Cloud-init only appends name server entries to this file, and
+# will not remove this bogus entry. Typically this leads to a delay of around
+# 30 seconds when connecting via SSH, due to a timeout in NSS. The workaround
+# employed here is to remove this bogus entry from the image using
+# virt-customize, if it exists. See https://bugs.centos.org/view.php?id=14369.
 #overcloud_host_image_workaround_resolv_enabled:
 
 # Workaround a CentOS 7.5 bug: cloud-init 0.7.9-24 does not correctly set