Asif Javed

Your Complete Guide to Setting Up an Ansible Automation Environment

Posted on by Asif

Are you tired of manually configuring servers one by one? Welcome to the world of Ansible, where infrastructure automation becomes simple, repeatable, and scalable. In this guide, I’ll walk you through setting up your first Ansible environment from scratch.

graph TB
    A[Control Node] --> B[Inventory Files]
    B --> C[Static Inventory]
    B --> D[Dynamic Inventory]
    C --> E[Playbooks]
    D --> E
    E --> F[Modules]
    F --> G[SSH Connection]
    F --> H[WinRM Connection]
    G --> I[Node1]
    G --> J[Node2]
    H --> K[Windows Server]
    I --> L[Configuration Applied]
    J --> L
    K --> L
    M[Ansible.cfg] -.-> A
    M -.-> G
    M -.-> H
    N[Variables] -.-> E
    O[Roles] -.-> F
    
    style A fill:#e1f5e1
    style C fill:#fffacd
    style D fill:#fffacd
    style I fill:#f0f8ff
    style J fill:#f0f8ff
    style K fill:#f0f8ff

Understanding Ansible Components

Before diving into configuration, let’s understand the four key pillars of Ansible:

  1. Inventories – Your list of managed machines
  2. Playbooks – YAML files defining what to do and in what order
  3. Modules – The workhorses that actually perform tasks
  4. Plugins – Extend functionality for logging, connections, and dynamic data

YAML: The Language of Ansible

Everything in Ansible—playbooks, roles, tasks, variables—is written in YAML. Remember these essentials:

  • Start files with --- (optional but recommended)
  • Key-value pairs form your data structure
  • Use - for list items
  • Indentation matters! It defines parent-child relationships

Setting Up Your Control Node

Prerequisites

  • Python 3.8 or later
  • Internet connectivity
  • RHEL 9.0+ (or Ubuntu with appropriate packages)

Installation Steps

# For RHEL-based systems
subscription-manager register
dnf list ansible-core
dnf install ansible-core

# Create Ansible user
sudo useradd ansible
sudo passwd ansible

Configuring Managed Nodes

Linux Prerequisites

  • Python 2.6 or later
  • SSH installed and enabled
  • Account with administrative privileges

Windows Prerequisites

  • PowerShell 3.0 or higher
  • WinRM enabled and configured
  • WinRM allowed through firewall
  • Administrative account

Building Your SSH Infrastructure

# Switch to ansible user
su ansible
cd ~

# Generate SSH keys
ssh-keygen

# Copy keys to managed nodes
ssh-copy-id node1
ssh-copy-id node2

Configuring Passwordless Sudo

On each managed node, create a sudoers file:

sudo vim /etc/sudoers.d/ansible

Add this line:

ansible ALL=(ALL) NOPASSWD: ALL

Verify with:

sudo systemctl restart crond

Creating Your First Inventory

Inventories can be static or dynamic. Let’s start with static:

mkdir ansible
vim inventory

Add your nodes:

node1
node2

Note: these nodes have been added to the host file with their corresponding IPs

Test connectivity:

ansible node1 -i inventory -m ping
ansible node2 -i inventory -m ping

Organizing with Groups

Create a more structured inventory with the following contents:

vim group_inventory
[webservers]
node1

[databaseservers]
node2

[production:children]
webservers
databaseservers

Configuring Ansible Defaults

Create ansible.cfg to simplify commands:

$ vim ansible.cfg
[defaults]
inventory=inventory
remote_user=ansible

[privilege_escalation]
become=true
become_method=sudo
become_user=root

Mastering Ad-Hoc Commands

Test basic operations:

# Check connectivity
ansible node1 -m ping

# Run commands
ansible all -m command -a "uptime"
ansible all -m command -a "whoami"

# Use shell module
ansible all -m shell -a "echo $HOME > /home/ansible/home.txt"

# File operations
ansible all -m copy -a "src=/etc/hosts dest=/home/ansible/host.file"
ansible all -m file -a "path=/home/ansible/testdir state=directory mode=0777"

Managing Packages and Services

# Install packages
ansible node2 -m dnf -a "name=httpd state=latest"

# Manage services
ansible all -m service -a "name=httpd state=started"
ansible all -m service -a "name=httpd state=stopped"
ansible all -m service -a "name=httpd state=restarted enabled=1"

# Check status
ansible all -m command -a "systemctl status httpd"

Creating Your First Playbook

Playbooks make automation repeatable. Configure your editor first:

vim ~/.vimrc

Add:

autocmd FileType yaml setlocal ai ts=2 sw=2 et

Now create your playbook:

---
- name: my first play
  hosts: node1
  tasks:
    - name: Ensure file exists
      file:
        path: /home/ansible/mytext.txt
        state: touch

    - name: Add welcome message
      lineinfile:
        path: /home/ansible/mytext.txt
        line: "Welcome from Playbook"

Run it:

ansible-playbook playbook.yml

Understanding Playbook Output Colors

  • Green: No changes made
  • Yellow/Orange: Changes were made
  • Red: Execution failed

Troubleshooting and Best Practices

Ansible Lint

Install this essential tool:

pip3 install --user ansible-lint
ansible-lint playbook.yml
ansible-lint -v playbook.yml  # Detailed report

Common Troubleshooting Steps

  1. Start with error logs
  2. Increase verbosity with -v, -vv, or -vvv
  3. Check syntax: ansible-playbook --syntax-check playbook.yml
  4. Dry run: ansible-playbook --check playbook.yml
  5. Use the debug module for variable inspection

Gathering Facts

# Method 1: Add in playbook
gather_facts: true

# Method 2: Ad-hoc command
$ ansible all -m setup

Dynamic Inventories

For cloud environments, create dynamic inventory scripts:

#!/usr/bin/env python3
import json
import sys

if __name__ == '__main__':
    if '--list' in sys.argv:
        print(json.dumps({
            "webservers": {
                "hosts": ["node1", "node2"],
                "vars": {
                    "ansible_user": "ansible"
                }
            },
            "_meta": {
                "hostvars": {
                    "node1": {
                        "ansible_host": "192.168.1.101"
                    },
                    "node2": {
                        "ansible_host": "192.168.1.102"
                    }
                }
            }
        }))
    elif '--host' in sys.argv:
        # This is for single host queries
        print(json.dumps({}))
    else:
        print(json.dumps({
            "webservers": {
                "hosts": ["node1", "node2"]
            }
        }))
# Make it executable
$ chmod +x dynamic_inventory.py

# Test with --list flag
$ ./dynamic_inventory.py --list

# Test in Ansible
$ ansible webservers -i dynamic_inventory.py --list-hosts

# Test ping with dynamic inventory
$ ansible webservers -i dynamic_inventory.py -m ping

Wrapping Up

You’ve now set up a complete Ansible environment! Remember:

  • Keep playbooks in version control
  • Use roles for complex configurations
  • Regularly run ansible-lint to maintain quality
  • Test with --check before applying changes

Ansible transforms infrastructure management from a chore into a streamlined process. Start small, automate one task at a time, and watch your efficiency soar.