--- - name: Set dns server for docker set_fact: docker_dns_servers: "{{ dns_servers }}" - name: Show docker_dns_servers debug: msg: "{{ docker_dns_servers }}" - name: Add upstream dns servers set_fact: docker_dns_servers: "{{ docker_dns_servers + upstream_dns_servers | default([]) }}" when: dns_mode in ['coredns', 'coredns_dual'] - name: Add global searchdomains set_fact: docker_dns_search_domains: "{{ docker_dns_search_domains + searchdomains | default([]) }}" - name: Check system nameservers shell: set -o pipefail && grep "^nameserver" /etc/resolv.conf | sed -r 's/^nameserver\s*([^#\s]+)\s*(#.*)?/\1/' args: executable: /bin/bash changed_when: False register: system_nameservers check_mode: no - name: Check system search domains # noqa risky-shell-pipe - if resolf.conf has no search domain, grep will exit 1 which would force us to add failed_when: false # Therefore -o pipefail is not applicable in this specific instance shell: grep "^search" /etc/resolv.conf | sed -r 's/^search\s*([^#]+)\s*(#.*)?/\1/' args: executable: /bin/bash changed_when: False register: system_search_domains check_mode: no - name: Add system nameservers to docker options set_fact: docker_dns_servers: "{{ docker_dns_servers | union(system_nameservers.stdout_lines) | unique }}" when: system_nameservers.stdout - name: Add system search domains to docker options set_fact: docker_dns_search_domains: "{{ docker_dns_search_domains | union(system_search_domains.stdout.split() | default([])) | unique }}" when: system_search_domains.stdout - name: Check number of nameservers fail: msg: "Too many nameservers. You can relax this check by set docker_dns_servers_strict=false in docker.yml and we will only use the first 3." when: docker_dns_servers | length > 3 and docker_dns_servers_strict | bool - name: Rtrim number of nameservers to 3 set_fact: docker_dns_servers: "{{ docker_dns_servers[0:3] }}" when: docker_dns_servers | length > 3 and not docker_dns_servers_strict | bool - name: Check number of search domains fail: msg: "Too many search domains" when: docker_dns_search_domains | length > 6 - name: Check length of search domains fail: msg: "Search domains exceeded limit of 256 characters" when: docker_dns_search_domains | join(' ') | length > 256