kubespray/roles/kubernetes/preinstall/tasks/resolvconf.yml

---
- name: check resolvconf
  shell: which resolvconf
  register: resolvconf
  ignore_errors: yes
  changed_when: false
  tags: facts

- name: check kubelet
  stat:
    path: "{{ bin_dir }}/kubelet"
  register: kubelet
  changed_when: false
  tags: facts

- name: check if early DNS configuration stage
  set_fact:
    dns_early: >-
      {%- if kubelet.stat.exists -%}false{%- else -%}true{%- endif -%}
  tags: facts

- name: target resolv.conf file
  set_fact:
    resolvconffile: >-
      {%- if resolvconf.rc == 0 -%}/etc/resolvconf/resolv.conf.d/head{%- else -%}/etc/resolv.conf{%- endif -%}
  when: ansible_os_family != "CoreOS"
  tags: facts

- name: target temporary resolvconf cloud init file
  set_fact:
    resolvconffile: /tmp/resolveconf_cloud_init_conf
  when: ansible_os_family == "CoreOS"
  tags: facts

- name: create temporary resolveconf cloud init file
  command: cp -f /etc/resolv.conf "{{ resolvconffile }}"
  when: ansible_os_family == "CoreOS"

- name: generate search domains to resolvconf
  set_fact:
    searchentries:
      "{{ ([ 'default.svc.' + dns_domain, 'svc.' + dns_domain ] + searchdomains|default([])) | join(' ') }}"
  tags: facts

- name: decide on dns server IP
  set_fact:
    dns_server_real: >-
      {%- if dns_early|bool -%}{{default_resolver}}{%- else -%}{{dns_server}}{%- endif -%}

- name: pick dnsmasq cluster IP or default resolver
  set_fact:
    dnsmasq_server: |-
      {%- if skip_dnsmasq|bool and not dns_early|bool -%}
        {{ [ skydns_server ] + upstream_dns_servers|default([]) }}
      {%- elif dns_early|bool -%}
        {{ [ dns_server_real ] + upstream_dns_servers|default([]) }}
      {%- else -%}
        {{ [ dns_server ] }}
      {%- endif -%}
  tags: facts

- name: generate nameservers to resolvconf
  set_fact:
    nameserverentries:
      "{{ dnsmasq_server|default([]) + nameservers|default([]) }}"
  tags: facts

- name: Remove search and nameserver options from resolvconf head
  lineinfile:
    dest: /etc/resolvconf/resolv.conf.d/head
    state: absent
    regexp: "^{{ item }}.*$"
    backup: yes
    follow: yes
  with_items:
    - search
    - nameserver
  when: resolvconf.rc == 0
  notify: Preinstall | update resolvconf

- name: Remove search and nameserver options from resolvconf cloud init temporary file
  lineinfile:
    dest: "{{resolvconffile}}"
    state: absent
    regexp: "^{{ item }}.*$"
    backup: yes
    follow: yes
  with_items:
    - search
    - nameserver
  when: ansible_os_family == "CoreOS"
  notify: Preinstall | update resolvconf for CoreOS

- name: Add search domains to resolvconf file
  lineinfile:
    line: "search {{searchentries}}"
    dest: "{{resolvconffile}}"
    state: present
    insertbefore: BOF
    backup: yes
    follow: yes
  notify: Preinstall | update resolvconf

- name: Add nameservers to resolv.conf
  blockinfile:
    dest: "{{resolvconffile}}"
    block: |-
      {% for item in nameserverentries -%}
      nameserver {{ item }}
      {% endfor %}
    state: present
    insertafter: "^search default.svc.*$"
    create: yes
    backup: yes
    follow: yes
    marker: "# Ansible nameservers {mark}"
  notify: Preinstall | update resolvconf

- name: Add options to resolv.conf
  lineinfile:
    line: options {{ item }}
    dest: "{{resolvconffile}}"
    state: present
    regexp: "^options.*{{ item }}$"
    insertafter: EOF
    backup: yes
    follow: yes
  with_items:
    - ndots:{{ ndots }}
    - timeout:2
    - attempts:2
  notify: Preinstall | update resolvconf

- name: Remove search and nameserver options from resolvconf base
  lineinfile:
    dest: /etc/resolvconf/resolv.conf.d/base
    state: absent
    regexp: "^{{ item }}.*$"
    backup: yes
    follow: yes
  with_items:
    - search
    - nameserver
  when: resolvconf.rc == 0
  notify: Preinstall | update resolvconf

- name: disable resolv.conf modification by dhclient
  copy: src=dhclient_nodnsupdate dest=/etc/dhcp/dhclient-enter-hooks.d/znodnsupdate mode=0755
  notify: Preinstall | restart network
  when: ansible_os_family == "Debian"

- name: disable resolv.conf modification by dhclient
  copy: src=dhclient_nodnsupdate dest=/etc/dhcp/dhclient.d/nodnsupdate mode=u+x
  notify: Preinstall | restart network
  when: ansible_os_family == "RedHat"

- name: get temporary resolveconf cloud init file content
  command: cat {{ resolvconffile }}
  register: cloud_config
  when: ansible_os_family == "CoreOS"

- name: persist resolvconf cloud init file
  template:
    dest: "{{resolveconf_cloud_init_conf}}"
    src: resolvconf.j2
    owner: root
    mode: 0644
  notify: Preinstall | update resolvconf for CoreOS
  when: ansible_os_family == "CoreOS"