Testing Ansible Playbook in a Docker Container

I am considerably new with Ansible and wanted to verify the changes I have made to an existing Ansible project. I found a nifty solution to my problem. I am now running the Ansible playbook inside a docker container. I got inspiration from couple of places that I should give credit to:

Testing Ansible Playbooks with Docker

How to connect to Docker from Ansible

Dockerize an SSH service

So what I have done is, I am creating a Docker container with the open-ssh server, sudo and python installed. Then I am adding an inventory for the docker container. Finally I am executing a bash script where I am building my image, running the container and then running the playbook on the container. I will show you just how I did it.

My Ansible project structure looks like this:

├── ansible
│   ├── env
│   │   └── local_docker
│   ├── roles
│   │   └── role1
│   │       └── tasks
│   │           └── main.yml
│   ├── myplaybook.yml
├── container-start-and-playbook-run.sh
└── docker
    ├── Dockerfile

The Dockerfile looks like this:

FROM ubuntu:16.04

RUN apt-get update && apt-get install -y openssh-server sudo python unzip
RUN mkdir /var/run/sshd
RUN echo 'root:screencast' | chpasswd
RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config

# SSH login fix. Otherwise user is kicked off after login
RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd

ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile

EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]

The content of my local_docker file looks like this:

[local]
ansible-test ansible_connection=docker

The ansible-test is the name of my container that I will create in my container-start-and-playbook-run.sh script. ansible_connection=docker is the part that tell Ansible that it needs to run the playbook inside the ansible-test container.

Now the content of myplaybook will need to refer to this local inventory that I have created. Like so:

---
  - hosts: local
    become: true
    roles:
      - role1

Finally the content of the bash script that puts everything together is:

#!/bin/bash

DOCKER_CONTAINER_NAME="ansible-test"

cd docker && docker build -t myubuntu .

docker run -ti --privileged --name $DOCKER_CONTAINER_NAME -d -p 5000:22 myubuntu

cd ../ansible && ansible-playbook -i env/local_docker myplaybook.yml -vvv
docker stop $DOCKER_CONTAINER_NAME

docker rm $DOCKER_CONTAINER_NAME

This has been greatly helpful for me, as I have zero confidence in my Ansible skills. Hope someone finds it helpful.