Ansible task to upgrade elasticsearch cluster.

upgrade_elasticsearch.yml

---
- name: get current elasticsearch version
  uri:
    url: http://localhost:9200
    method: GET
    headers:
      Content-Type: application/json
  register: current_elasticsearch_version

- block:
  - set_fact:
      es_home: "/usr/share/elasticsearch"

  - name: get node status
    uri:
      url: http://localhost:9200/_cluster/health?pretty
      method: GET
      headers:
        Content-Type: application/json
    register: pre_upgrade_cluster_state

  - name: print elastic_response
    debug:
      msg: "{{ pre_upgrade_cluster_state }}"

  - name: disable shard allocation
    uri:
      url: http://localhost:9200/_cluster/settings
      method: PUT
      body: '{ "transient": { "cluster.routing.allocation.enable": "none" } }'
      headers:
        Content-Type: application/json
    register: elastic_response

  - name: Stop non-essential indexing and perform a synced flush
    uri:
      url: http://localhost:9200/_flush/synced?pretty
      method: POST
    ignore_errors: yes
    register: elastic_response2

  - name: stop elasticsearch service
    service:
      name: elasticsearch
      state: stopped

  - name: remove aws cloud plugin
    command: "{{ es_home }}/bin/elasticsearch-plugin remove discovery-ec2"

  - name: upgrade elasticsearch
    apt:
      pkg: "elasticsearch={{ elasticsearch_version }}"
      state: present
      update_cache: yes

  - name: install aws cloud plugin
    command: "{{ es_home }}/bin/elasticsearch-plugin install discovery-ec2"

  - name: start elasticsearch service
    service:
      name: elasticsearch
      state: started

  - name: wait for node to come up
    wait_for:
      host: localhost
      port: 9200
      delay: 10

  - name: Verify the node has joined the cluster
    uri:
      url: http://localhost:9200/_cluster/health?pretty
      method: GET
      headers:
        Content-Type: application/json
    register: post_upgrade_cluster_state
    until: pre_upgrade_cluster_state.json.number_of_nodes == post_upgrade_cluster_state.json.number_of_nodes
    retries: 10
    delay: 10

  - name: enable shard allocation
    uri:
      url: http://localhost:9200/_cluster/settings
      method: PUT
      body: '{ "transient": { "cluster.routing.allocation.enable": "all" } }'
      headers:
        Content-Type: application/json

  - name: Ensure cluster is back to green
    uri:
      url: http://localhost:9200/_cluster/health?pretty
      method: GET
      headers:
        Content-Type: application/json
    register: final_cluster_health
    until: final_cluster_health.json.status == "green"
    retries: 1000
    delay: 30

  - name: print post upgrade cluster state
    debug:
      msg: "{{ final_cluster_health }}"

  when: current_elasticsearch_version.json.version.number != elasticsearch_version