Ansible: 'item' is undefined

Question

I'm trying to use with_items with delegate_to to run a Docker container in several hosts. I have a group test in /etc/ansible/hosts:

[test]
my_machine1
my_machine2

And this task:

 - name: Run app container
    docker:
      name: "{{artifact_id}}"
      insecure_registry: true
      image: "{{image}}:{{version}}"
      pull: always
      state: reloaded
      ports:
      - "{{port_mapping}}"
      delegate_to: '{{item}}'
      with_items:
      - "{{groups['test']}}"

But when I run it, I get this error:

{"failed": true, "msg": "ERROR! 'item' is undefined"}

What am I doing wrong?

Thanks in advance

Solution

You need to take care of indention. delegate_to and with_items are part of the task, not of the docker module.

- name: Run app container
  docker:
    name: "{{artifact_id}}"
    insecure_registry: true
    image: "{{image}}:{{version}}"
    pull: always
    state: reloaded
    ports:
      - "{{port_mapping}}"
  delegate_to: '{{item}}'
  with_items: "{{groups['test']}}"

Though I'm not sure your delegation will work here. What is the background why you need to delegate it in the first place? The normal way would be to apply the play to the hosts of the group test. I guess you're instead running the play against localhost?

_{Another unrelated thing: I experienced issues with the docker module when pull: always used together with state: reloaded. Unlike docker-compose, the docker module will always restart the container no matter if there was an updated image pulled or not.}

---

- hosts: localhost
  tasks:
    - download nexus
    - build image
    - upload to registry
    - ...
- hosts: test
  tasks:
    - docker: ...

Comments

[Michael]

Your formatting seems off. Could you format the question yaml just to avoid confusion?

[Héctor]

LOL, It was the problem! delegate_to and with_items are not docker module's properties but task itself ones -.-" Thanks.

[Héctor]

Thank you very much. It solved the problem. Yes, I'm running in localhost several actions (download the image from nexus and build it) and the last one, that is run the container, must be executed in test machines. Should I do it another way? Thank you.

[udondan]

You could add a 2nd play. The 1st play builds your image and (I guess uploads it to a private registry). The 2nd play runs the docker module. I added a dummy example playbook above. But I see how the delegation makes sense for you. If the delegation indeed works, go for it if you prefer it that way.

[Héctor]

Perfect. Thank you again.