Automating Server Setup with Ansible: A Practical Guide

by

Introduction

Managing server setups manually can be time-consuming, error-prone, and inefficient, especially in environments with multiple servers or repetitive configuration tasks. Ansible, a powerful open-source IT automation tool, simplifies this process by allowing you to automate server provisioning, configuration, and management.

In this guide, we’ll provide a practical introduction to using Ansible for automating the setup and configuration of Ubuntu Server. By the end of this article, you’ll know how to write and execute Ansible playbooks to automate common server tasks, saving time and ensuring consistency across your infrastructure.

Why Use Ansible for Server Automation?

Ansible is widely used for server automation because of its simplicity and power. Here’s why it’s a top choice:

  • Agentless: Ansible doesn’t require any agent software to be installed on the target servers. It uses SSH for communication.
  • Declarative Syntax: Ansible playbooks use YAML, a human-readable syntax, making it easy to define desired states.
  • Reusable Configurations: Write playbooks once and reuse them across multiple servers.
  • Idempotent: Ansible ensures tasks are only executed if necessary, avoiding redundant operations.
  • Extensibility: Ansible supports a wide range of modules to handle tasks like package installation, file management, and service configuration.

Prerequisites

Before we dive into automating Ubuntu Server setup with Ansible, ensure you have the following:

  1. Control Node: A machine (your local system or a dedicated server) where Ansible is installed.
  2. Target Servers: Ubuntu Servers (on-premises or in the cloud) that you want to configure.
  3. SSH Access: Ensure passwordless SSH access is set up between the control node and the target servers.

Step 1: Install Ansible

1.1 Install Ansible on the Control Node

On your control node (e.g., your local machine running Ubuntu), install Ansible:

sudo apt update  
sudo apt install ansible -y

1.2 Verify Installation

Check the installed version of Ansible to ensure it’s installed correctly:

ansible --version

Example output:

ansible 2.10.8
  config file = None
  configured module search path = ['/home/uadmin/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.10.12 (main, Feb  4 2025, 14:57:36) [GCC 11.4.0]

Step 2: Set Up SSH Access

Ansible communicates with target servers over SSH. You’ll need to set up passwordless SSH access from the control node to the target servers.

2.1 Generate an SSH Key Pair

If you don’t already have an SSH key pair, generate one:

ssh-keygen -t rsa -b 2048

2.2 Copy the SSH Key to Target Servers

Use the following command to copy your public key to the target server(s):

ssh-copy-id ubuntu@<target-server-ip>

Test SSH access to ensure it works without a password:

ssh ubuntu@<target-server-ip>

Step 3: Define Your Inventory

Ansible uses an inventory file to define the target servers you want to manage.

3.1 Create an Inventory File

Create a file named inventory in your working directory:

nano inventory

Add the IP addresses or hostnames of the target servers. For example:

[ubuntu_servers]  
192.168.50.42  
192.168.50.145

Save and exit the file (Ctrl+O, then Ctrl+X).

3.2 Test Connectivity

Use the ping module to test connectivity to the target servers:

ansible -i inventory ubuntu_servers -m ping

Example output:

192.168.50.145 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
192.168.50.42 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}

Step 4: Write Your First Ansible Playbook

Ansible playbooks are YAML files that define the tasks you want to automate. Let’s create a playbook to automate the setup of an Ubuntu Server.

4.1 Create a Playbook File

Create a file named setup.yml:

nano setup.yml

4.2 Define the Playbook

Add the following content to the playbook:

---  
- name: Configure Ubuntu Server  
  hosts: ubuntu_servers  
  become: true  

  tasks:  
    - name: Update and upgrade apt packages  
      apt:  
        update_cache: yes  
        upgrade: dist  

    - name: Install common packages  
      apt:  
        name:  
          - curl  
          - wget  
          - git  
          - build-essential  
        state: present  

    - name: Enable UFW and allow SSH  
      ufw:  
        rule: allow  
        name: OpenSSH  
        state: enabled  

    - name: Create a new user  
      user:  
        name: devuser  
        password: "{{ 'password123' | password_hash('sha512') }}"  
        state: present  
        groups: sudo

Explanation of Tasks

  1. Update and Upgrade Packages: Ensures the server has the latest updates and security patches.
  2. Install Common Packages: Installs essential tools like curl, wget, and git.
  3. Enable UFW: Configures the firewall to allow SSH access.
  4. Create a New User: Adds a new user with sudo privileges.
  5. Set Hostname: Configures the server’s hostname.

Save and exit the file.

Step 5: Run the Playbook

Execute the playbook to apply the configurations:

ansible-playbook -i inventory setup.yml

Ansible will log the progress of each task. If all tasks complete successfully, your Ubuntu Server will be fully configured.

Output Below:

uadmin@u2204-001:~$ sudo ansible-playbook -i inventory setup.yml

PLAY [Configure Ubuntu Server] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************
ok: [192.168.50.145]
ok: [192.168.50.42]

TASK [Update and upgrade apt packages] *******************************************************************************
^X^C [ERROR]: User interrupted execution
uadmin@u2204-001:~$ sudo nano setup.yml
uadmin@u2204-001:~$ sudo ansible-playbook -i inventory setup.yml

PLAY [Configure Ubuntu Server] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************
ok: [192.168.50.145]
ok: [192.168.50.42]

TASK [Update and upgrade apt packages] *******************************************************************************
ok: [192.168.50.42]
ok: [192.168.50.145]

TASK [Install common packages] ***************************************************************************************
changed: [192.168.50.145]
changed: [192.168.50.42]

TASK [Enable UFW and allow SSH] **************************************************************************************
changed: [192.168.50.145]
changed: [192.168.50.42]

TASK [Create a new user] *********************************************************************************************
changed: [192.168.50.42]
changed: [192.168.50.145]

PLAY RECAP ***********************************************************************************************************
192.168.50.145             : ok=5    changed=3    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
192.168.50.42              : ok=5    changed=3    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Step 6: Verify the Configuration

6.1 Check Installed Packages

Log in to one of the target servers and verify that the common packages were installed:

curl --version  
git --version

6.2 Check Firewall Status

Verify that the firewall is enabled:

sudo ufw status

6.3 Check New User

Ensure the new user was created:

cat /etc/passwd | grep devuser

Advanced Use Cases

Once you’re comfortable with basic playbooks, you can explore more advanced use cases:

  • Deploying Applications: Use Ansible to install and configure web servers (e.g., Nginx, Apache) or databases (e.g., MySQL, PostgreSQL).
  • Managing Multiple Environments: Create separate inventory files for staging, production, and development environments.
  • Using Roles: Organize your playbooks into reusable roles for complex setups.
  • Integrating with CI/CD: Automate server setup as part of your CI/CD pipeline.

Conclusion

Ansible is a powerful tool for automating server setup and configuration. In this guide, we covered:

  • Installing Ansible on the control node.
  • Setting up SSH access to target servers.
  • Writing and executing a basic playbook to automate Ubuntu Server setup.

By leveraging Ansible, you can save time, reduce errors, and ensure consistency across your infrastructure. Whether you’re managing a single server or hundreds, Ansible is an essential tool for modern DevOps workflows.

Leave a Comment