kubespray/roles/kubernetes/control-plane/tasks/kubeadm-upgrade.yml

---
- name: kubeadm | Check api is up
  uri:
    url: "https://{{ ip | default(fallback_ips[inventory_hostname]) }}:{{ kube_apiserver_port }}/healthz"
    validate_certs: false
  when: inventory_hostname in groups['kube_control_plane']
  register: _result
  retries: 60
  delay: 5
  until: _result.status == 200

- name: kubeadm | Upgrade first master
  command: >-
    timeout -k 600s 600s
    {{ bin_dir }}/kubeadm
    upgrade apply -y {{ kube_version }}
    --certificate-renewal={{ kubeadm_upgrade_auto_cert_renewal }}
    --config={{ kube_config_dir }}/kubeadm-config.yaml
    --ignore-preflight-errors=all
    --allow-experimental-upgrades
    --etcd-upgrade={{ etcd_deployment_type == "kubeadm" | bool | lower }}
    --force
  register: kubeadm_upgrade
  # Retry is because upload config sometimes fails
  retries: 3
  until: kubeadm_upgrade.rc == 0
  when: inventory_hostname == first_kube_control_plane
  failed_when: kubeadm_upgrade.rc != 0 and "field is immutable" not in kubeadm_upgrade.stderr
  environment:
    PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}"
  notify: Master | restart kubelet

- name: kubeadm | Upgrade other masters
  command: >-
    timeout -k 600s 600s
    {{ bin_dir }}/kubeadm
    upgrade apply -y {{ kube_version }}
    --certificate-renewal={{ kubeadm_upgrade_auto_cert_renewal }}
    --config={{ kube_config_dir }}/kubeadm-config.yaml
    --ignore-preflight-errors=all
    --allow-experimental-upgrades
    --etcd-upgrade={{ etcd_deployment_type == "kubeadm" | bool | lower }}
    --force
  register: kubeadm_upgrade
  when: inventory_hostname != first_kube_control_plane
  failed_when:
    - kubeadm_upgrade.rc != 0
    - '"field is immutable" not in kubeadm_upgrade.stderr'
  environment:
    PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}"
  notify: Master | restart kubelet

- name: kubeadm | clean kubectl cache to refresh api types
  file:
    path: "{{ item }}"
    state: absent
  with_items:
    - /root/.kube/cache
    - /root/.kube/http-cache

# FIXME: https://github.com/kubernetes/kubeadm/issues/1318
- name: kubeadm | scale down coredns replicas to 0 if not using coredns dns_mode
  command: >-
    {{ kubectl }}
    -n kube-system
    scale deployment/coredns --replicas 0
  register: scale_down_coredns
  retries: 6
  delay: 5
  until: scale_down_coredns is succeeded
  run_once: yes
  when:
    - kubeadm_scale_down_coredns_enabled
    - dns_mode not in ['coredns', 'coredns_dual']
  changed_when: false