elasticsearch-wait-for-cluster-health.yml

---

# Make sure shard allocation is enabled
- name: Enable shard allocation for the cluster
  ansible.builtin.uri:
    url: "{{ elasticsearch_http_protocol }}://{{ elasticsearch_api_host }}:{{ elasticstack_elasticsearch_http_port }}/_cluster/settings"
    method: PUT
    body: '{ "persistent": { "cluster.routing.allocation.enable": null }}'
    body_format: json
    user: elastic
    password: "{{ elasticstack_password.stdout }}"
    validate_certs: no
  register: response
  # next line is boolean not string, so no quotes around true
  # use python truthiness
  until: "response.json.acknowledged == true"
  retries: 5
  delay: 30

# From https://www.elastic.co/guide/en/elastic-stack/8.17/upgrading-elasticsearch.html
## During a rolling upgrade, primary shards assigned to a node running the new version cannot have their replicas assigned to a node with the old version. The new version might have a different data format that is not understood by the old version.
##
## If it is not possible to assign the replica shards to another node (there is only one upgraded node in the cluster), the replica shards remain unassigned and status stays yellow.
##
## In this case, you can proceed once there are no initializing or relocating shards (check the init and relo columns).

- name: Check cluster health
  block:
  - name: Wait for cluster health to return to green
    ansible.builtin.uri:
      url: "{{ elasticsearch_http_protocol }}://{{ elasticsearch_api_host }}:{{ elasticstack_elasticsearch_http_port }}/_cluster/health"
      method: GET
      user: elastic
      password: "{{ elasticstack_password.stdout }}"
      validate_certs: no
    register: response
    until: "response.json.status == 'green'"
    retries: 50
    delay: 30

  # Timed out while waiting for green cluster
  # Check if we can continue with a yellow cluster
  rescue:
    - name: "Rescue: Check if cluster health is yellow"
      ansible.builtin.uri:
        url: "{{ elasticsearch_http_protocol }}://{{ elasticsearch_api_host }}:{{ elasticstack_elasticsearch_http_port }}/_cluster/health"
        method: GET
        user: elastic
        password: "{{ elasticstack_password.stdout }}"
        validate_certs: no
      register: response
      failed_when: "response.json.status != 'yellow' or response.json.relocating_shards != 0 or response.json.initializing_shards != 0"

    - name: "Rescure: Wait before verifying status"
      ansible.builtin.pause:
        seconds: 10

    - name: "Rescue: Verify we can safely continue with yellow cluster"
      ansible.builtin.uri:
        url: "{{ elasticsearch_http_protocol }}://{{ elasticsearch_api_host }}:{{ elasticstack_elasticsearch_http_port }}/_cluster/health"
        method: GET
        user: elastic
        password: "{{ elasticstack_password.stdout }}"
        validate_certs: no
      register: response
      failed_when: "response.json.status != 'yellow' or response.json.relocating_shards != 0 or response.json.initializing_shards != 0"