Make the LXC container create use the host resolver config

The current container creation process overrides the DNS resolution
configuration instead of consuming the configuration implemented
in the container cache preparation.

With the implementation of change I66b448dee361e231d172eb278b290ec4dccfdf97
The container cache makes use of the host resolver configuration.

This patch ensures that the container create process falls into line
with that instead of overriding the cache configuration.

Change-Id: I0f12a50471e670a03e17bfaa2c150a8da3f63af4

defaults/main.yml

@@ -55,7 +55,3 @@ lxc_container_download_template_options: >
   --force-cache
   --server {{ lxc_image_cache_server }}
   --variant={{ lxc_container_variant }}
-
-lxc_cache_resolvers:
-  - 'nameserver 8.8.8.8'
-  - 'nameserver 8.8.4.4'

vars/redhat-7.yml

@@ -45,10 +45,6 @@ lxc_container_map:
   release: 7
   prep_commands: |
     mkdir -p /var/backup
-    rm /etc/resolv.conf
-    {% for resolver in lxc_cache_resolvers %}
-    echo "{{ resolver }}" | tee -a /etc/resolv.conf
-    {% endfor %}
     if [ -f  "/usr/lib/systemd/system/poweroff.target" ];then
       ln -sf /usr/lib/systemd/system/poweroff.target /etc/systemd/system/sigpwr.target || true
     fi

vars/ubuntu-14.04.yml

@@ -53,12 +53,6 @@ lxc_container_map:
   release: trusty
   prep_commands: |
     mkdir -p /var/backup
-    echo '# Null Tail' | tee /etc/resolvconf/resolv.conf.d/tail
-    echo '# Null original' | tee /etc/resolvconf/resolv.conf.d/original
-    rm /etc/resolvconf/resolv.conf.d/base
-    {% for resolver in lxc_cache_resolvers %}
-    echo 'nameserver {{ resolver }}' | tee -a /etc/resolvconf/resolv.conf.d/base
-    {% endfor %}
     if [ -f  "/usr/lib/systemd/system/poweroff.target" ];then
       ln -sf /usr/lib/systemd/system/poweroff.target /etc/systemd/system/sigpwr.target || true
     fi

vars/ubuntu-16.04.yml

@@ -53,12 +53,6 @@ lxc_container_map:
   release: xenial
   prep_commands: |
     mkdir -p /var/backup
-    echo '# Null Tail' | tee /etc/resolvconf/resolv.conf.d/tail
-    echo '# Null original' | tee /etc/resolvconf/resolv.conf.d/original
-    rm /etc/resolvconf/resolv.conf.d/base
-    {% for resolver in lxc_cache_resolvers %}
-    echo 'nameserver {{ resolver }}' | tee -a /etc/resolvconf/resolv.conf.d/base
-    {% endfor %}
     if [ -f  "/usr/lib/systemd/system/poweroff.target" ];then
       ln -sf /usr/lib/systemd/system/poweroff.target /etc/systemd/system/sigpwr.target || true
     fi