kubespray/roles/network_plugin/flannel/tasks/main.yml

---
- name: Flannel | Set Flannel etcd configuration
  command: |-
    {{ bin_dir }}/etcdctl --peers={{ etcd_access_addresses }} \
    set /{{ cluster_name }}/network/config \
    '{ "Network": "{{ kube_pods_subnet }}", "SubnetLen": {{ kube_network_node_prefix }}, "Backend": { "Type": "{{ flannel_backend_type }}" } }'
  delegate_to: "{{groups['etcd'][0]}}"
  run_once: true

- name: Flannel | Create flannel certs directory
  file:
    dest: "{{ flannel_cert_dir }}"
    state: directory
    mode: 0750
    owner: root
    group: root

- name: Flannel | Link etcd certificates for flanneld
  file:
    src: "{{ etcd_cert_dir }}/{{ item.s }}"
    dest: "{{ flannel_cert_dir }}/{{ item.d }}"
    state: hard
    force: yes
  with_items:
    - {s: "ca.pem", d: "ca_cert.crt"}
    - {s: "node-{{ inventory_hostname }}.pem", d: "cert.crt"}
    - {s: "node-{{ inventory_hostname }}-key.pem", d: "key.pem"}

- name: Flannel | Create flannel pod manifest
  template:
    src: flannel-pod.yml
    dest: "{{kube_manifest_dir}}/flannel-pod.manifest"
  notify: Flannel | delete default docker bridge

- name: Flannel | Wait for flannel subnet.env file presence
  wait_for:
    path: /run/flannel/subnet.env
    delay: 5
    timeout: 600

- name: Flannel | Get flannel_subnet from subnet.env
  shell: cat /run/flannel/subnet.env | awk -F'=' '$1 == "FLANNEL_SUBNET" {print $2}'
  register: flannel_subnet_output
  changed_when: false
  check_mode: no

- set_fact:
    flannel_subnet: "{{ flannel_subnet_output.stdout }}"

- name: Flannel | Get flannel_mtu from subnet.env
  shell: cat /run/flannel/subnet.env | awk -F'=' '$1 == "FLANNEL_MTU" {print $2}'
  register: flannel_mtu_output
  changed_when: false
  check_mode: no

- set_fact:
    flannel_mtu: "{{ flannel_mtu_output.stdout }}"

- set_fact:
    docker_options_file: >-
      {%- if ansible_os_family == "Debian" -%}/etc/default/docker{%- elif ansible_os_family == "RedHat" -%}/etc/sysconfig/docker{%- endif -%}
  tags: facts

- set_fact:
    docker_options_name: >-
      {%- if ansible_os_family == "Debian" -%}DOCKER_OPTS{%- elif ansible_os_family == "RedHat" -%}other_args{%- endif -%}
  tags: facts

- set_fact:
    docker_network_options: '"--bip={{ flannel_subnet }} --mtu={{ flannel_mtu }}"'

- name: Flannel | Ensure path for docker network systemd drop-in
  file:
    path: "/etc/systemd/system/docker.service.d"
    state: directory
    owner: root

- name: Flannel | Create docker network systemd drop-in
  template:
    src: flannel-options.conf.j2
    dest: "/etc/systemd/system/docker.service.d/flannel-options.conf"
  notify:
    - Flannel | restart docker