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Configuring Docker Via Ansible

Hello everyone, you all might have seen the power of docker, a container managing software by directly. But to use it with remote systems isn’t an tedious task when you have to configure same type of configuration in different-different flavours of OS’s

Yes it is tedious task so, in this article I would like to explain how to use ansible a configuration management tool, to manage docker.

The pre-requisites are that you should have ansible configured on the system and you are all set.

The task is as below :

🔹 Configure Docker

🔹 Start and enable Docker services

🔹 Pull the httpd server image from the Docker Hub

🔹 Run the docker container and expose it to the public

🔹 Copy the html code in /var/www/html directory and start the web server

Now, let’s write task for for configuring the docker,

- name: Docker repository conf

  yum_repository:
    name: dockername
    description: desc for docker
    baseurl: https://download.docker.com/linux/centos/8/x86_64/stable/
    gpgcheck: no

Checking if docker is already present

- stat: path=/usr/bin/docker
  register: docker_present

this task will install the docker library of python

- name: install python3 docker sdk
   pip:
     name: docker

Installing docker via yum it will not install if it is already installed

- name: install docker
   command: "yum install docker-ce --nobest -y"
   when: not docker_present.stat.exists

Now finally starting the docker service

- name: start service for docker
  service:
    name: docker
    state: started
    enabled: yes

Creating a folder on the host docker container so that later we can transfer the files from there to the container

- name: "Creating folder in docker host"
  file:
    path: "/web"
    state: directory

Copying the files from the controller node to the managed node

- name: "Copying the files in the host system"
  copy:
    src: "index.html"
    dest: "/web"

Finally creating and starting the container from the httpd image of docker

- name: "Creating OS from httpd image"
  docker_container:
  name: "ansible_apache"
  image: "httpd"
  state: started
  exposed_ports:
    - "80"   
    ports:   
    - "8844:80"   
    volumes:
    - /web:/usr/local/apache2/htdocs/

Full playbook

We have now successfully launched the webserver on top of docker. to see whether it is a success or not go to the managed node and type the following command.

docker inspect <name of image> | grep IP to get the IP address of container

curl <IP> to access the content of web page

Thanks for reading 🔥🔥😊😊