Install Ansible on Ubuntu [20.04]

Ansible is the simplest way to automate apps and IT infrastructure. It is an open-source software provisioning, configuration management, and application-deployment tool enabling infrastructure as code. It runs on many Unix-like systems and can configure both Unix-like systems as well as Microsoft Windows.

In this article, we will install Ansible on Ubuntu 20.04 and use it to connect to other VMs.

Ansible Architecture

Ansible works by connecting to your nodes and pushing out scripts called “Ansible modules” to them. Most modules accept parameters that describe the desired state of the system. Ansible then executes these modules (over SSH by default) and removes them when finished.

Prerequisites

A workstation node to implement the Ansible Management Node.
A non-root user with sudo privileges.
One or more host nodes.
SSH access from the workstation to host nodes (set up the SSH key pair).

Installing Ansible

Add the Ansible repository to apt and install Ansible using the following commands:

sudo apt-add-repository ppa:ansible/ansible
sudo apt update
sudo apt install ansible

This will install Ansible on your workstation, which will function as the management node.

Add Remote Hosts to Inventory File

You need to add remote servers to the Ansible inventory file located at /etc/ansible/hosts:

sudo vim /etc/ansible/hosts

Here is an example of defining servers as groups:

[masters]
master ansible_host=host_ip_1 ansible_user=ansibleuser

[workers]
worker1 ansible_host=host_ip_2 ansible_user=ansibleuser
worker2 ansible_host=host_ip_3 ansible_user=ansibleuser
worker3 ansible_host=host_ip_4 ansible_user=ansibleuser

[all:vars]
ansible_python_interpreter=/usr/bin/python3

Replace host_ip_x with the IP addresses of your Ansible hosts and ansibleuser with your Ansible user.

Verify the inventory list:

ansible-inventory --list -y

Expected output:

all:
  children:
    masters:
      hosts:
        master:
          ansible_host: host_ip_1
          ansible_python_interpreter: /usr/bin/python3
          ansible_user: ansibleuser
    ungrouped: {}
    workers:
      hosts:
        worker1:
          ansible_host: host_ip_2
          ansible_python_interpreter: /usr/bin/python3
          ansible_user: ansibleuser
        worker2:
          ansible_host: host_ip_3
          ansible_python_interpreter: /usr/bin/python3
          ansible_user: ansibleuser
        worker3:
          ansible_host: host_ip_4
          ansible_python_interpreter: /usr/bin/python3
          ansible_user: ansibleuser

Test Connection

To test the connection to remote hosts via Ansible, use the ping module:

ansible all -m ping -u root

Expected output:

worker3 | SUCCESS => {
   "changed": false,
   "ping": "pong"
}
worker1 | SUCCESS => {
   "changed": false,
   "ping": "pong"
}
worker2 | SUCCESS => {
   "changed": false,
   "ping": "pong"
}
master | SUCCESS => {
   "changed": false,
   "ping": "pong"
}

For the first connection, Ansible will ask to confirm the authenticity of the hosts. Type yes and press enter to proceed.

Originally published at onloadcode.com on November 28, 2020.