docker_container module always falsely report 'changed' and 'kernel_memory' attribute seems to be the culprit

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1

I have a playbook which in the end ensure that a docker container with provided attributes is started. So consider this task below (stripped off some of the stuff)

`

  • name: Start container
    docker_container:
    name: “{{cname}}”
    image: “{{ image }}”
    state: started
    memory: “{{ mem }}”
    memory_reservation: “{{ memr }}”
    memory_swap: “{{ mems }}”
    kernel_memory: 0

`

This setup was working fine earlier but when i updated to Ansible 2.4.3, this container task would always report changed, while nothing at all is changed for the container on docker host. The container is not even being restarted and yet this task would show ‘changed’. I tried to compare the json returned by the above task with the json of docker inspect on my container, and they were exactly the same.

During debugging, i started commenting out some attributes and when i commented out ‘kernel_memory’, it stopped reporting ‘changed’ and now it is back to the intended behavior of ‘OK’. So i know this attribute is the culprit, i just don’t know what is wrong. I check Ansible 2.6 as well and it has the same problem.

Can anyone please explain what am i doing wrong here or is it some problem in the docker_container module ?

2

Hi,

I have a playbook which in the end ensure that a docker container
with provided attributes is started. So consider this task below
(stripped off some of the stuff)

      - name: Start container
        docker_container:
          name: "{{cname}}"
          image: "{{ image }}"
          state: started
          memory: "{{ mem }}"
          memory_reservation: "{{ memr }}"
          memory_swap: "{{ mems }}"
          kernel_memory: 0

This setup was working fine earlier but when i updated to Ansible
2.4.3, this container task would *always report changed*, while

which version of Ansible did you use before? And did you also upgrade
the docker-py / docker Python package (on the nodes)?

During debugging, i started commenting out some attributes and when i
commented out 'kernel_memory', it stopped reporting 'changed' and now
it is back to the intended behavior of 'OK'. So i know this attribute
is the culprit, i just don't know what is wrong. I check Ansible 2.6
as well and it has the same problem.

Can anyone please explain what am i doing wrong here or is it some
problem in the docker_container module ?

I debugged this a bit; the problem is that the argument kernel_memory
("0", i.e. as a string) is compared to a number (0); the comparison
fails and docker_container things there is some work to do. I've looked
at various versions of the docker_container module, the code always
looked very similar, so I doubt this ever worked differently.

(Actually, it could be that older versions did not set changed=True when
updating the limits, so this wasn't visible with older versions of
Ansible.)

Anyway, this is a bug in the docker_container module IMO. You should
create a ticket for it:
https://github.com/ansible/ansible/issues/new?template=bug_report.md

Cheers,
Felix

3

Hi Felix,

Providing 0 or “0” values has the same undesired result. Although, if i provide empty value (‘’), then it runs just fine.

I have raised a bug here - https://github.com/ansible/ansible/issues/42692

BR,
Ishan

4

Could someone please let me know how to go about updating/patching Ubuntu systems via Ansible playbook.

5

Can someone please tell me what I am doing wrong with the Ansible Playbook syntax. Listed below is the Playbook and the error I am getting.

Basic provisioning example

  • ec2:

key_name: Ansible

instance_type: t2.micro

image: ami-db710fa3

group_id: sg-d271b9a2

wait: yes

volumes:

  • device_name: /dev/xvda

volume_type: gp2

volume_size: 8

delete_on_termination: true

count: 3

vpc_subnet_id: subnet-a29fdcf8

assign_public_ip: yes

ERROR! ‘ec2’ is not a valid attribute for a Play

The error appears to have been in ‘/private/etc/ansible/playbooks/ec2.yml’: line 2, column 3, but may

be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

Basic provisioning example

  • ec2:

^ here

6

This is not a playbook but a task, recommend you read this
https://docs.ansible.com/ansible/latest/user_guide/playbooks_intro.html

7

I live in Mountain View, CA and am looking for someone with Ansible expertise who I can spend 2-3 hours with in order to get up to speed with Ansible. I am willing to pay $100/hr or whatever it takes.

Thanks,
Syed Jafar