Fix getting nameserver and search for /etc/resolv.conf with comments (#5197)

roles/container-engine/docker/tasks/set_facts_dns.yml

@@ -29,13 +29,13 @@
     docker_dns_search_domains: "{{ docker_dns_search_domains + searchdomains|default([]) }}"
 
 - name: check system nameservers
-  shell: grep "^nameserver" /etc/resolv.conf | sed 's/^nameserver\s*//'
+  shell: grep "^nameserver" /etc/resolv.conf | sed -r 's/^nameserver\s*([^#\s]+)\s*(#.*)?/\1/'
   changed_when: False
   register: system_nameservers
   check_mode: no
 
 - name: check system search domains
-  shell: grep "^search" /etc/resolv.conf | sed 's/^search\s*//'
+  shell: grep "^search" /etc/resolv.conf | sed -r 's/^search\s*([^#]+)\s*(#.*)?/\1/'
   changed_when: False
   register: system_search_domains
   check_mode: no