How to install docker on ubuntu using ansible?

 

 

Installation of docker on Ubuntu using ansible

 

Below are the steps to be followed to install docker on ubuntu using ansible

 

1. Create a new Ansible playbook file, for example docker_setup.yml.
2. Define the hosts or host group on which you want to install Docker. For example, if you want to install Docker on a group of Ubuntu servers with the tag docker_servers, you can define it like this:

 

- name: Install Docker on Ubuntu servers

  hosts: docker_servers

 

3. Define the tasks required to install and set up Docker:

- name: Install Docker on Ubuntu servers

  hosts: docker_servers

- name: Install aptitude

  apt: name=aptitude state=present

 

- name: Install required system packages

  apt: name={{ item }} state=present

  with_items:

    - apt-transport-https

    - ca-certificates

    - curl

    - gnupg-agent

    - software-properties-common

 

- name: Install Docker GPG APT key

  apt_key:

    url: https://download.docker.com/linux/ubuntu/gpg

    state: present

 

- name: Add Docker repository to apt sources

  apt_repository:

    repo: deb [arch=amd64] https://download.docker.com/linux/ubuntu {{ ansible_distribution_release }} stable

    state: present

 

- name: Install Docker

  apt: name=docker-ce state=present

 

- name: Install Python Docker module via pip

  pip:

    name: docker

 

- name: Pull default Docker image

  docker_image:

    name: "{{ default_container_image }}"

    state: present

 

- name: Create Docker containers

  docker_container:

    name: "{{ default_container_name }}{{ item }}"

    image: "{{ default_container_image }}"

    command: "{{ default_container_command }}"

    state: started

  with_sequence: start=1 count={{ container_count }}

      

The above playbook consists of several tasks, each of which performs a specific action:

• The first task installs the aptitude package manager, which is preferred by Ansible as an alternative to apt.
• The second task installs several required system packages, including apt-transport-https, ca-certificates, curl, gnupg-agent, and software-properties-common.
• The third task installs the Docker GPG APT key, which is necessary to authenticate the Docker packages.
• The fourth task adds the official Docker repository to the server's APT sources.
• The fifth task installs Docker itself using the apt package manager.
• The sixth task installs the Python Docker module via pip.
• The seventh task pulls the default Docker image specified by the default_container_image variable from Docker Hub.
• The eighth task creates the number of Docker containers defined by the container_count variable, each using the image defined by default_container_image, and executes the command defined in default_container_command in each new container.

This playbook uses several Ansible modules to perform these tasks, including apt, apt_key, apt_repository, pip, docker_image, and docker_container. The with_items and with_sequence directives are used to loop through lists of items and perform the same task multiple times with different parameters.

 

4. Define the variables required for the playbook to run. You can define these variables in a separate file and include it in the playbook, or you can define them inline in the playbook. Here's an example of defining variables inline:

- name: Install Docker on Ubuntu servers

  hosts: docker_servers

  vars:

    default_container_image: ubuntu:latest

    default_container_name: my_container

    default_container_command: /bin/bash

    container_count: 3

 

In this example, we're using the ubuntu:latest image, naming our containers my_container, running the /bin/bash command in each container, and creating 3 containers.

5. Run the playbook using the ansible-playbook command:

ansible-playbook docker_setup.yml

Below is the kind of output observed when above command is executed

$ ansible-playbook docker_setup.yml

 

PLAY [Install Docker on Ubuntu servers] *********************************************************************

 

TASK [Gathering Facts] **************************************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Install aptitude] *************************************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Install required system packages] *********************************************************************

ok: [server1] => (item=apt-transport-https)

ok: [server2] => (item=apt-transport-https)

ok: [server3] => (item=apt-transport-https)

ok: [server1] => (item=ca-certificates)

ok: [server2] => (item=ca-certificates)

ok: [server3] => (item=ca-certificates)

ok: [server1] => (item=curl)

ok: [server2] => (item=curl)

ok: [server3] => (item=curl)

ok: [server1] => (item=gnupg-agent)

ok: [server2] => (item=gnupg-agent)

ok: [server3] => (item=gnupg-agent)

ok: [server1] => (item=software-properties-common)

ok: [server2] => (item=software-properties-common)

ok: [server3] => (item=software-properties-common)

 

TASK [Install Docker GPG APT key] ***************************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Add Docker repository to apt sources] ****************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Install Docker] **************************************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Install Python Docker module via pip] ****************************************************************

ok: [server1]

ok: [server2]

ok: [server3]

 

TASK [Pull default Docker image] ***************************************************************************

changed: [server1]

changed: [server2]

changed: [server3]

 

TASK [Create Docker containers] ****************************************************************************

changed: [server1] => (item=1)

changed: [server1] => (item=2)

changed: [server1] => (item=3)

changed: [server2] => (item=1)

changed: [server2] => (item=2)

changed: [server2] => (item=3)

changed: [server3] => (item=1)

changed: [server3] => (item=2)

changed: [server3] => (item=3)

 

PLAY RECAP *************************************************************************************************

server1                    : ok=8    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0  

server2                    : ok=8    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0  

server3                    : ok=8    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0