jinja2 templating - Ansible

Question

In Ansible, I currently have vars set out like this

    container_a_version: 1
    container_b_version: 6
    container_c_version: 3
    container_d_version: 2
    ...

    containers:
     - container_a
     - container_b
     - container_c
     - container_d  
    ... 

Each container has its own template file which has a line like this

    image: registry.sportpesa.com/sportpesa/global/container-a:{{ container_a_version }}

My playbook

    - name: Copy templates
      template:
        src: templates/docker-compose-{{ item }}.yml
        dest: /srv/docker-compose-{{ item }}.yml
      loop: "{{ containers }}"

If I want to deploy only container a and c. I change my variable to this

    containers:
     - container_a
    # - container_b
     - container_c
    # - container_d 

 

What I want to do condense my variables to just have 1 var like this

    containers:
      - { name: a, version: 1 }
      - { name: b, version: 6 }
      - { name: c, version: 3 }
      - { name: d, version: 2 }

However I'm not sure how I can call the container version in my template. Is this possible?

Answer 1

In your loop, you can call a field of the item looped like this:

name: {{ item.name }}
version: {{ item.version }}

I assume you have to put this in your scpecific context. Looks this documentation for more details about jinja templating if necessary.

Answer 2

Put the data into a dictionary

    containers:
      a: 1
      b: 6
      c: 3
      d: 2

    containers_enabled: [a, c]

and iterate enabled containers only. For example

- debug:
    msg:
      - "{{ src }}"
      - "{{ dest }}"
      - "{{ image }}"
  loop: "{{ containers_enabled }}"
  vars:
    src: "templates/docker-compose-container_{{ item }}.yml"
    dest: "/srv/docker-compose-container_{{ item }}.yml"
    image: "container-{{ item }}{{ containers[item] }}"

^{not tested}