--- - name: set dns server for docker set_fact: docker_dns_servers: "{{ dns_servers }}" - name: show docker_dns_servers debug: msg: "{{ docker_dns_servers }}" - name: set base docker dns facts set_fact: docker_dns_search_domains: - 'default.svc.{{ dns_domain }}' - 'svc.{{ dns_domain }}' docker_dns_options: - ndots:{{ ndots }} - timeout:2 - attempts:2 - 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: 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 -r 's/^search\s*([^#]+)\s*(#.*)?/\1/' 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 all.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