Run Command Inside of Docker Container Using Ansible

Question

what I\'m trying to accomplish is to run commands inside of a Docker container that has already been created on a Digital Ocean Ubuntu/Docker Droplet using Ansible.

Answer 1

You should be able to execute a script (with your sequence of command in it) with docker exec:

docker exec container-name bash -l -c /path/to/script > /path/to/log

(See also "Why do I have to use bash -l -c inside my container?")

• /path/to/script should be accessible by your Ansible process.
• /path/to/log is a path inside the container, that could be shared in a volume.

Answer 2

Ended up doing something like that:

- name: execute command in docker
  shell: |
    docker exec container sh -l -c "cat /tmp/secret"
  register: hello

- debug: msg="{{ hello.stdout }}"

Answer 3

Update: there is a way to do this without using my module, see my other answer

I wrote a simple module to run exec on a remote Docker host. I've submitted it to the ansible project, but you can easily add it to your own projects if you need to. The module is only 23 lines long, take it from my pull request and add it to your ./library directory, and then you can add a task in your playbook like so:

  - name: Run docker exec command
    docker_exec: 
      command: <some command>
      docker_host: <docker host>
      name: <container name>
    register: exec_output

  - name: Show exec output
    debug: msg="{{ exec_output.result }}"

Answer 4

You can run commands within docker containers using the command module For example this code will execute echo "Hello1" and echo "Hello2" in my_container:

   tasks:
        - name: Execute commands in docker container
          command: docker exec -it my_container bash -c 'echo "Hello1"; echo "Hello2"'

Answer 5

After discussion with some very helpful developers on the ansible github project, a better way to do this is like so:

- name: add container to inventory
  add_host:
    name: [container-name]
    ansible_connection: docker
  changed_when: false

- name: run command in container
  delegate_to: [container-name]
  raw: bash

If you have python installed in your image, you can use the command module or any other module instead of raw.

If you want to do this on a remote docker host, add:

ansible_docker_extra_args: "-H=tcp://[docker-host]:[api port]"

to the add_host block.

See the Ansible documentation for a more complete example.