Split deploy steps in separate playbooks: part1 (#3451)

* Fix bootstrap_os/ubuntu idempotency

* Update bastion role

* move container_engine in sub-roles

* requires ansible 2.5

* ubuntu18 as first CI job

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

@@ -0,0 +1,71 @@
+---
+
+- 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 (only when dnsmasq is not used)
+  set_fact:
+    docker_dns_servers: "{{ docker_dns_servers + upstream_dns_servers|default([]) }}"
+  when: dns_mode in ['kubedns', '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 's/^nameserver\s*//'
+  changed_when: False
+  register: system_nameservers
+  check_mode: no
+
+- name: check system search domains
+  shell: grep "^search" /etc/resolv.conf | sed 's/^search\s*//'
+  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