pcs-container-update

Ansible module for uniform updates to pacemaker container resources.

Requirements

1. The 'pcs' command-line interface utility
2. A Pacemaker High-Availability cluster with container resources
3. Podman or Docker

Full Overview

This is a module for updating container resources being managed by pacemaker in a high-availability cluster. It finds the node the given resource is running on, then compares digests of the new pulled image and the running container image, and updates the container with the new image if the digests are different. This role uses the 'pcs' command-line interface tool to restart the resource if the digests are not equal. It is required to first pull newer images using the Podman/Docker modules with Ansible. This module does not do that for you. It also does not provide rolling updates; this is a uniform update, meaning the resource will experience downtime while it restarts with the newer image. If the resource has dependencies, such as in a resource group, the dependent resources will be stopped to update the given container resource.

Example

Example playbook for including the module in your playbook

- hosts: servers
  roles:
    - jacksonsteiner.ansible_pcs_container_update

Example playbook for using the module to update a container resource

# Update the pacemaker resource postgres running in a podman container
- name: Update Postgres
  pcs_container_update:
    name: postgres

# Update the pacemaker resource nginx running in a podman container
- name: Update nginx
  pcs_container_update:
    name: nginx
    engine: podman

# Update the pacemaker resource nginx running in a docker container
- name: Update nginx
  pcs_container_update:
    name: nginx
    engine: docker

Documentation

Look at the full documentation and examples with

ansible-doc -M library/ pcs_container_update