Automating Your Infrastructure with Ansible: A Beginner’s Guide

9 min readApr 9, 2023

What is Ansible?

Ansible is an open-source IT automation tool designed to simplify the process of configuring and managing computer systems, network devices, and applications. It is written in Python and uses a declarative language to describe system configurations and automate tasks.

With Ansible, users can define the desired state of their infrastructure and applications using YAML files called playbooks, which describe the steps that Ansible should take to achieve that state. Ansible then executes these steps across all the hosts defined in the playbook.

Some of the key features of Ansible include:

Agentless architecture: Ansible uses SSH or WinRM to connect to remote hosts, which means it does not require any agent software to be installed on the managed nodes.
Idempotent execution: Ansible ensures that the desired state is achieved regardless of the current state of the system, and it does not make unnecessary changes to achieve the desired state.
Large ecosystem: Ansible has a large community and a vast collection of pre-built modules, playbooks, and roles that can be used to automate various tasks.
Extensibility: Ansible can be extended using custom modules and plugins to support complex workflows and integrate with other tools and platforms.

Ansible is used by IT operations teams, system administrators, developers, and DevOps engineers to automate the provisioning, configuration, deployment, and management of IT infrastructure and applications.

Use Cases

Ansible can be used to automate various IT operations and manage a wide range of systems and applications. Some of the most common use cases of Ansible include:

Configuration management: Ansible can be used to manage the configuration of servers, network devices, and applications. It can ensure that the desired configuration is applied across all the systems in the infrastructure.
Provisioning: Ansible can be used to automate the process of provisioning new servers and applications. It can create new virtual machines, configure them, and install the required software and services.
Continuous deployment: Ansible can be integrated into the continuous deployment pipeline to automate the deployment of new releases of applications. It can ensure that the new release is deployed consistently and reliably across all the environments.
Security and compliance: Ansible can be used to automate security and compliance tasks such as patching, vulnerability scanning, and configuration auditing. It can ensure that the systems are up-to-date, secure, and compliant with the relevant standards.
Orchestration: Ansible can be used to orchestrate complex workflows and automate multi-step tasks. It can coordinate the execution of tasks across multiple systems and ensure that they are executed in the correct order.
Cloud automation: Ansible can be used to automate the management of cloud infrastructure and services. It can provision, configure, and manage cloud resources such as virtual machines, storage, and networking.

Overall, Ansible provides a flexible and powerful platform for automating IT operations and managing infrastructure and applications at scale.

Ansible Connections

In Ansible, a connection is a method used to connect to the managed nodes and execute tasks. Ansible supports various connection types, depending on the type of system or application being managed.

Here are some of the common connection types used in Ansible:

SSH connection: This is the most common connection type used in Ansible. It uses the SSH protocol to connect to the managed nodes and execute tasks. It works with both Linux and Unix-based systems.
WinRM connection: This connection type is used to manage Windows systems. It uses the Windows Remote Management (WinRM) protocol to connect to the managed nodes and execute tasks.
Local connection: This connection type is used to execute tasks locally on the Ansible control node. It is useful for tasks such as copying files or executing shell commands.
Docker connection: This connection type is used to manage Docker containers. It uses the Docker API to connect to the Docker daemon and manage the containers.
Kubernetes connection: This connection type is used to manage Kubernetes clusters. It uses the Kubernetes API to connect to the cluster and manage the resources.
Network connection: This connection type is used to manage network devices such as routers, switches, and firewalls. It uses various protocols such as Telnet, SSH, and SNMP to connect to the devices and execute tasks.

The connection type used in Ansible is specified in the inventory file or the playbook, depending on the use case. By using the appropriate connection type, Ansible can manage a wide range of systems and applications, making it a versatile and flexible tool for IT automation.

Ansible Architecture

Ansible follows a client-server architecture, where the control node acts as the server and the managed nodes act as the clients. The control node is the Ansible host where Ansible is installed and executed, and the managed nodes are the target hosts that Ansible will configure and manage.

The Ansible architecture consists of the following components:

Inventory: The inventory is a configuration file that lists the managed nodes and their details, such as IP addresses, hostnames, and connection type. It defines the scope of the playbooks and roles and provides a way to group and organize the managed nodes.
Playbooks: Playbooks are YAML files that define the desired state of the managed nodes and the steps that Ansible should take to achieve that state. They consist of one or more plays, which are a set of tasks that are executed on a group of hosts.
Modules: Modules are the units of work in Ansible. They are reusable code blocks that perform a specific task, such as installing a package, copying a file, or restarting a service. Ansible comes with a large collection of built-in modules, and users can also create their own custom modules.
Roles: Roles are a way to organize and reuse playbooks and tasks. They allow users to group related tasks and configurations and share them across multiple playbooks.
Ansible Engine: Ansible Engine is the core component of Ansible that orchestrates the execution of playbooks and tasks. It parses the playbooks, connects to the managed nodes, and executes the tasks using the appropriate modules.
Ansible Vault: Ansible Vault is a tool used to encrypt sensitive data such as passwords, SSH keys, and other credentials in the playbooks and roles.
Plugins: Plugins provide additional functionality to Ansible, such as inventory plugins, connection plugins, and module plugins. They allow users to extend Ansible and integrate it with other tools and platforms.

Overall, the Ansible architecture is designed to be flexible and modular, allowing users to customize and extend Ansible to meet their specific needs.

Ansible Power

Ansible provides several powerful features that make it a popular choice for IT automation and configuration management. Here are some of the key strengths of Ansible:

Agentless: Ansible is an agentless tool, meaning that it does not require any software to be installed on the managed nodes. This makes it easy to deploy and manage and reduces the complexity of the infrastructure.
Simple and easy to learn: Ansible uses YAML syntax for defining playbooks and roles, which is easy to read and write. It also has a low learning curve, making it accessible to users with different levels of experience.
Idempotent: Ansible is designed to be idempotent, meaning that it will always ensure that the desired state of the system is achieved, regardless of the current state. This ensures consistency and predictability in the infrastructure.
Cross-platform support: Ansible supports a wide range of operating systems, including Linux, Unix, macOS, and Windows, as well as cloud platforms such as AWS, Azure, and Google Cloud Platform.
Scalable: Ansible is designed to be scalable, allowing users to manage hundreds or even thousands of nodes with ease. It also supports parallel execution, which helps to reduce the time required to execute tasks.
Role-based access control: Ansible provides role-based access control (RBAC), which allows users to control access to the infrastructure based on roles and permissions.
Community support: Ansible has a large and active community of users and contributors, who provide support, contribute modules and plugins, and share best practices.

Overall, Ansible provides a powerful and flexible platform for IT automation and configuration management, with a wide range of features and capabilities. It can help to improve the efficiency, consistency, and reliability of IT operations, and reduce the risk of errors and downtime.

Ansible Example

here’s an example of how to use Ansible to configure a web server on a Linux machine step by step:

1. Install Ansible: The first step is to install Ansible on the control node. This can be done by running the following command on a Linux machine:

sudo apt-get update
sudo apt-get install ansible

2. Set up SSH keys: Ansible uses SSH to connect to the managed nodes, so it’s important to set up SSH keys for passwordless authentication. This can be done by generating a key pair on the control node using the following command:

ssh-keygen

Then copy the public key to the managed nodes using the following command:

ssh-copy-id <user>@<managed-node>

3. Create an inventory file: The inventory file is a list of managed nodes that Ansible will manage. It can be created using a text editor and saved as a file, for example, inventory.ini. Here's an example of what it might look like:

[webservers]
web1 ansible_host=192.168.0.1 ansible_user=ubuntu
web2 ansible_host=192.168.0.2 ansible_user=ubuntu

This defines a group of managed nodes called webservers, with two nodes named web1 and web2. The ansible_host and ansible_user variables specify the IP address and username for each node.

4. Create a playbook: The playbook is a YAML file that defines the tasks that Ansible will perform on the managed nodes. It can be created using a text editor and saved as a file, for example, webservers.yml. Here's an example of what it might look like:

---
- name: Install Apache web server
  hosts: webservers
  become: yes
  tasks:
  - name: Update apt cache
    apt:
      update_cache: yes
  - name: Install Apache web server
    apt:
      name: apache2
      state: present
  - name: Start Apache service
    service:
      name: apache2
      state: started
      enabled: yes

This playbook performs three tasks on the managed nodes:

Update the apt cache
Install the Apache web server
Start the Apache service

The hosts variable specifies the group of managed nodes to apply the tasks to, and the become variable allows Ansible to run the tasks as a privileged user.

5. Run the playbook: Finally, the playbook can be executed using the ansible-playbook command. For example, to run the webservers.yml playbook on the managed nodes defined in the inventory.ini file, run the following command:

ansible-playbook -i inventory.ini webservers.yml

This will execute the playbook on the managed nodes and configure the Apache web server.

6. Verify the configuration: To verify that the configuration was successful, open a web browser and navigate to the IP address of one of the managed nodes. If everything was configured correctly, you should see the default Apache web page.

This example covers the basic concepts of inventory, playbooks, and tasks in Ansible. With these concepts, you can build more complex playbooks to automate a wide range of tasks on your infrastructure.

What’s Next?

We will look into the concepts of each feature listed above and will do small hands-on exercises to understand the implementation of each of those concepts.

Mastering DevOps: A Comprehensive Step-by-Step Guide to Elevate Your Skills and Enhance Your Workflow
1. Software Development Life Cycle (SDLC)
2. History Of DevOps
3. What is DevOps
4. DevOps LifeCycle
5. What is Git? — Git operation and command
6. What is Version Control System? — Git vs GitHub
7. The Most Important Linux Commands
8. Vagrant — The Complete Guide
9. The Power of Virtualization
10. Networking Guide
11. Bash Scripts: An In-Depth Tutorial
12. Architecture: Monolithic vs Microservices
13. CI/CD Workflow with Jenkins
14. Automating Your Infrastructure with Ansible
15. Docker Made Easy From Beginner to Advanced in One Guide
16. Creating a Custom Docker Image
17. Examples of Docker File With Various Application Stacks
18. Kubernetes A Beginner’s Tutorial
19. Kubernetes feature: Pods, Services, Replicasets, Controllers, Namespaces, Config, and Secrets
20. Terraform: Simplify Infrastructure Management
Level up your DevOps skills with our easy-to-follow tutorials, perfect for acing exams and expanding your knowledge. Stay tuned for more concepts and hands-on projects to boost your expertise!