kubespray/roles/etcd/tasks/join_member.yml

---
- name: Join Member | Add member to cluster
  shell: "{{ bin_dir }}/etcdctl --endpoints={{ etcd_access_addresses }} member add {{ etcd_member_name }} {{ etcd_peer_url }}"
  register: member_add_result
  until: member_add_result.rc == 0
  retries: 4
  delay: "{{ retry_stagger | random + 3 }}"
  when: target_node == inventory_hostname

- include: refresh_config.yml
  vars:
    etcd_peer_addresses: >-
      {% for host in groups['etcd'] -%}
        {%- if hostvars[host]['etcd_member_in_cluster'].rc == 0 -%}
          {{ "etcd"+loop.index|string }}=https://{{ hostvars[host].access_ip | default(hostvars[host].ip | default(hostvars[host].ansible_default_ipv4['address'])) }}:2380,
        {%- endif -%}
        {%- if loop.last -%}
          {{ etcd_member_name }}={{ etcd_peer_url }}
        {%- endif -%}
      {%- endfor -%}      
  when: target_node == inventory_hostname

- name: Join Member | reload systemd
  command: systemctl daemon-reload
  when: target_node == inventory_hostname

- name: Join Member | Ensure etcd is running
  service:
    name: etcd
    state: started
    enabled: yes
  when: target_node == inventory_hostname

- name: Join Member | Ensure member is in cluster
  shell: "{{ bin_dir }}/etcdctl --no-sync --endpoints={{ etcd_access_addresses }} member list | grep -q {{ etcd_access_address }}"
  register: etcd_member_in_cluster
  changed_when: false
  check_mode: no
  tags:
    - facts
  when: target_node == inventory_hostname