Working with Ansible and Docker

As shown in the diagram, we are trying to provision, docker container in remote host using a intermediate docker container (Docker-Ansible) which has been installed Ansible.

So Ansible playbook will run inside the docker container which is in local host.

By this way you don't have to install Ansible in local machine.

Also we can execute multiple playbook at the same time.

Please note, for this demonstration I am using single machine. You can use two virtual machines instead of single machine with different IP address.

Steps.

1. Install Open-SSH server in Ubuntu.

Please follow below article for this.

https://www.cyberciti.biz/faq/ubuntu-linux-install-openssh-server/

2. Setup SSH keys in Ubuntu.

Please follow below article for this

https://www.digitalocean.com/community/tutorials/how-to-set-up-ssh-keys-on-ubuntu-1604

https://www.ssh.com/ssh/copy-id

3. Install Docker

https://dhanuka84.blogspot.com/2019/02/install-docker-in-ubuntu.html

4. Install Python

https://tecadmin.net/install-python-2-7-on-ubuntu-and-linuxmint/

5. Clone below two github projects

git clone https://github.com/dhanuka84/docker-ansible.git



git clone https://github.com/dhanuka84/docker-ansible-playbook.git

6. Build each project

cd   docker-ansible/master-ubuntu16.04

docker-ansible/master-ubuntu16.04$   docker build -t ansible-docker:master-ubuntu16.04 .

cd   docker-ansible-playbook

docker-ansible-playbook$   docker build -t docker-ansible-intermediate:latest .

7. Provisioning the container using intermediate container

cd   docker-ansible-playbook



docker-ansible-playbook$  ./start.sh

Explanation

1. Docker image ansible-docker:master-ubuntu16.04

If you look at the Dockerfile, you can see it has setup up all the things mentioned in the diagram as Docker-Ansible. This will be the generic Ubuntu based image.

2. docker-ansible-intermediate:latest

We use previous image as parent image in here. Mainly what we do with this image is setup SSH keys and hosts

Though define ssh-keyscan 192.168.0.114  > /root/.ssh/known_hosts in the image level is not the best approach for this just for demo purpose we did like this.

Best approach is do the same in container level  (start.sh) instead of image level.

3. docker-ansible-playbook$ vim docker.yml  playbook

---

- hosts: docker

#  gather_facts: no

  tasks:



  - name: Create container

    docker_container:

     name: docker-test

    # docker_host: "tcp://localhost:22"

    # This is a pre-built ubuntu based image. Also it has been installed python-pip as explain in the #diagram.

   #We use this image as provisioned container

     image: nitincypher/docker-ubuntu-python-pip:latest

    # image: ansible:ubuntu16.04

     command: sleep 1d

     detach: true

     interactive: true

     tty: true

    # tls_hostname: localhost




     tls_verify: yes

References:

https://developer.ibm.com/tutorials/cl-provision-docker-containers-ansible/