What is Ansible and What is it used for? | Beginner’s Guide

Ansible is one of the most widely used automation tools in IT, DevOps, cloud, and network automation. It helps engineers automate repetitive tasks such as server configuration, application deployment, cloud provisioning, security updates, and network device management.

Instead of logging into each system separately, engineers can specify tasks using simple YAML playbooks. Ansible will then execute the tasks across several systems via one control node.

In this blog, we will help you understand what Ansible is, how Ansible works as well as what Ansible is used for. We will also explain how beginners can get started using Ansible through practical examples.

What is Ansible?

Ansible is an open-source IT automation tool that is used for managing configurations, application deployment cloud provisioning, security automation, orchestration and automation of networks.

Ansible utilizes a basic human-readable language, called YAML (YAML isn’t an official markup language) to describe automated tasks as playbooks. It runs these tasks using a control node on managed systems using SSH or WinRM (Windows remote management connection) without the need for agents on each target machine as it is an agentless system.

In simple words, Ansible helps engineers automate repeated IT tasks with readable files instead of manual commands. It is used by various working professionals including DevOps engineers, system admins, cloud engineers, and network engineers for workstations and servers, application deployment, cloud provisioning, intra-service orchestration, configuration management, and almost everything system managers do regularly.

Ansible Features

Some of the notable features of Ansible are:

• Agentless Architecture: Ansible connects through SSH, which means no software runs on managed servers. The control node handles all the logic and execution.
• Simple Language: Ansible makes use of YAML for configuration. Tasks mentioned in YAML are simple, plain English.
• Idempotent Execution: Tasks run multiple times safely. Systems reach the desired state without breaking.
• Parallel Processing: Ansible can easily control many servers at once. All the tasks can run simultaneously.
• Secure by Design: Ansible encrypts passwords with Vault and uses SSH keys. Credentials stay protected in playbooks.

Why Is Ansible Used?

Ansible is mainly used because manual infrastructure management is slow, repetitive and, error prone. When teams manage hundreds of routers, servers, switches, or cloud instances, even small errors can lead to major problems. Ansible can solve this issue by transforming repeatable tasks into automation files. These files can be used again or reviewed, re-configured, and run across a variety of systems.

Ansible is commonly used for:

• Configuration management
• Application deployment
• Cloud provisioning
• Network automation
• Security and compliance
• Orchestration
• Patch management
• Disaster recovery
• CI/CD workflows

Let us now discuss each of these use cases in detail.

What is Ansible used for? – Use Cases

Some of the significant use cases of Ansible are:

Configuration Management

Ansible shines at keeping servers consistent. You write playbooks that define how systems should look. Then Ansible makes it happen. Need Apache on 50 servers? One playbook does it all. If you change your mind about a setting? Update the playbook and then rerun it. Every server matches perfectly.

Application Deployment

Deploying apps manually takes forever. Ansible automates the whole process. It copies files, sets permissions, and restarts services. Your app goes from development to production smoothly.

Cloud Provisioning

Building cloud infrastructure used to mean clicking through web interfaces. Now Ansible talks directly to AWS, Azure, or Google Cloud. It spins up servers, configures networks, and sets up storage. Everything happens through code.

Security and Compliance

Keeping systems secure requires constant updates. Ansible patches servers, rotates passwords, and configures firewalls. It runs compliance checks, too. When auditors ask about your security setup, you show them the playbooks.

CI/CD Workflows

Modern teams deploy code multiple times daily. Ansible fits perfectly into CI/CD pipelines. It handles the deployment piece, working with tools like Jenkins or GitLab. Code changes flow automatically from the repository to production.

Network Automation

Network devices need updates, too. Ansible configures routers, switches, and firewalls from major vendors. It backs up configs, pushes changes, and validates settings. Network teams save hours by automating repetitive tasks. One playbook can update VLANs across your entire network.

Disaster Recovery

When systems crash, every minute counts. Ansible helps rebuild infrastructure fast. Your playbooks become recovery documentation. They restore servers, databases, and applications in the right order. What took hours manually now happens in minutes. Regular disaster drills become simple, just run the playbooks and verify everything works.

Ansible for DevOps

Ansible is widely used in DevOps because it helps teams automate deployment and infrastructure tasks.

DevOps teams use Ansible to:

• deploy applications
• configure servers
• manage environment consistency
• run repeatable release tasks
• automate rollback steps
• integrate deployment workflows with CI/CD tools

Ansible playbooks can be stored in Git. This allows teams to review, version, and reuse automation just like application code. This makes Ansible useful for teams that want faster releases and fewer manual deployment errors.

How Ansible Works?

Ansible works by connecting to nodes and pushing out small programs known as ansible modules. It then implements these modules over SSH by default and then eliminates them when finished.

The Ansible management node is the control node, which handles the complete implementation of the playbook. It is the node from which users are performing the installation, and the inventory file provides a list of hosts where the module needs to run. The management node allows SSH connections, and then it applies the module to the host machines and installs the product and once installed it removes the module.

Ansible Architecture

Ansible architecture is a simple design that works without agents on target machines. The control node runs commands and sends them to be managed nodes through SSH. No special software is needed to run on remote systems. This makes setup fast and secure.

The architecture of Ansible follows a push model. You write tasks in YAML files called playbooks. These run from the control node to configure multiple servers at once.

Core Components of Ansible Architecture 

Control Node

This is where Ansible runs. You install Ansible here and run all commands from this point. It connects to other servers using SSH keys. The control node needs Python installed to work properly. 

Managed Nodes

These are the servers Ansible configures. They don’t need Ansible installed. Just Python and SSH access. Each node runs the tasks sent by the control node. They can be physical servers, VMs, or cloud instances. 

Modules

Ansible Modules are critical software that Ansible distributes from one command computer to all nodal network points or remote hosts. They are predefined instructions that are applied directly to the remote host. Playbooks run modules that maintain applications, packages, and files. Ansible invokes all modules to deliver updates or perform the required activity and disconnects them after completion.

It has over 450 modules for specific tasks. It contains hundreds of built-in modules and code that run when a playbook is launched. A playbook consists of plays, consisting of various tasks, consisting of modules.

Playbook

Ansible Playbooks are YAML files that automate IT tasks. Each playbook contains plays that map hosts to roles and tasks. System administrators write these files to describe what they want systems to look like. 

Playbooks run tasks in order across multiple machines. They install software, copy files, start services, and manage configurations. The YAML format makes them easy to read and write. Teams store playbooks in version control systems like Git. 

Instead of logging into servers manually, engineers run playbooks once. This approach saves time, prevents mistakes, and ensures every server matches the desired configuration perfectly. 

Plugins

Ansible plugins are small pieces of code that extend Ansible’s functionality. They help Ansible handle things like connections, inventory, lookups, filters, callbacks, and task execution. Ansible provides many built-in plugins, and users can create their own custom plugins.

Inventory

Ansible inventory includes all the nodes or hosts that need to be taken care of, along with their IP addresses, databases, server details, and other information. All machines (controls and nodes) used with Ansible are listed in a single, easy-to-read file containing this comprehensive data. After registering the inventory, one can assign parameters to multiple hosts through a simple text-based format.

For network engineers, Ansible inventory is very important. It can include routers, switches, firewalls, load balancers, and lab devices. A clean inventory helps engineers run playbooks on the right devices without manual selection.

Roles

Ansible Roles help in organizing playbooks and files. Roles group related tasks, variables, and files together. They make sharing code easier. You can download roles from Ansible Galaxy or create your own.

Below, we have discussed each component of Ansible architecture in a tabular form.

Component	Role in Ansible
Control Node	The machine where Ansible commands and playbooks run
Managed Nodes	Servers, devices, or systems managed by Ansible
Inventory	A file or source that lists managed nodes
Playbooks	YAML files that define automation tasks
Modules	Small units of code that perform tasks
Plugins	Extensions that add extra Ansible behavior
Collections	Packages that contain modules, plugins, roles, and playbooks
Roles	Reusable structure for organizing playbooks

Ansible follows a push-based model in most common setups. The control node pushes instructions to managed nodes and runs tasks remotely. This agentless model is one of Ansible’s biggest advantages. Managed nodes do not usually need Ansible installed on them.

How to Install Ansible on Ubuntu?

Understanding only theory won’t help you on how to use Ansible. To better understand each and every component and how it works, it’s better to do it yourself by installing Ansible.

Use the following commands on an Ubuntu-based system.

Step I:  Updates the local package list so Ubuntu knows the latest available software versions.

sudo apt update

Step II: Installs tools needed to manage software repositories, including the add-apt-repository command.

sudo apt install software-properties-common –y

Step III: Adds the official Ansible PPA repository and updates the package list automatically.

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

Step IV: Installs Ansible from the available repositories without asking for confirmation.

sudo apt install ansible –y

Step V: Check whether Ansible is installed or not.

ansible –version

After all the steps, it is highly recommended to run a simple local test.

ansible all -i localhost, --connection=local -m ping

Note: Installation steps can change based on operating system and Ansible version. For production environments, always verify the latest installation method from Ansible’s official documentation.

Let us move on to next section where we will discuss how you can use Ansible for network automation.

Ansible for Network Automation

Ansible is not only used for servers and DevOps. Network engineers also use Ansible to automate routers, switches, firewalls, and other network devices.

For beginners, it is helpful to first understand what network automation is and then follow a proper network automation roadmap before moving into tools like Ansible.

In network automation, Ansible can help with:

• Configuration backup
• VLAN configuration
• Interface changes
• Routing configuration checks
• Firewall policy updates
• Compliance validation
• Command execution across multiple devices
• Standard configuration deployment

For example, a network engineer can use Ansible to collect show version output from multiple Cisco routers.

First, install the Cisco IOS collection:

ansible-galaxy collection install cisco.ios

Example Inventory

Example Playbook

This playbook connects to Cisco routers and runs a show command automatically.

Output for the Command

Let us now discuss the basic difference between Ansible, Terraform, Puppet, and Chef.

Ansible vs Terraform vs Puppet vs Chef

Tool	Best used for	Key difference
Ansible	Configuration management, automation, orchestration	Agentless and YAML playbook-based
Terraform	Infrastructure provisioning	Declarative infrastructure as code
Puppet	Configuration management	Agent-based and policy-driven
Chef	Configuration management	Ruby-based automation framework

Ansible and Terraform are often compared, but they solve different problems. Terraform is usually stronger for creating infrastructure. Ansible is usually stronger for configuring systems and automating operational tasks after infrastructure exists. Many teams use both tools together. Terraform can provision infrastructure, and Ansible can configure that infrastructure.

For a detailed comparison between Ansible and Terraform, read our blog on Ansible vs Terraform.

Benefits of Ansible

Ansible offers many benefits to IT and team members involved in network automation.

Agentless setup

Ansible doesn’t require agents on the majority of managed nodes. It generally utilizes SSH for Linux and network devices, as well as WinRM for Windows. This makes the deployment process simpler than many automation tools based on agents.

Simple syntax for YAML

Ansible playbooks make use of YAML. YAML is easy to read and understand for beginners than many programming languages. This is beneficial to system administrators, DevOps engineers, and network engineers to automate their work faster.

Idempotent execution

Ansible aims to bring systems into that desired state. If the desired state already exist, Ansible does not make unnecessary changes. This makes the repeated execution of playbooks more secure and predictable.

Large ecosystem

Ansible can be used with a variety of operating systems, cloud platforms, and network devices via collections and modules. This makes Ansible beneficial across security, cloud, infrastructure, and networking teams.

Good for teams

Playbooks can be saved in Git and reviewed by team members and reused across different environments. This supports better collaboration and less manual errors

Limitations of Ansible

Ansible is an extremely powerful tool; however, beginners should be aware of its limitations.

YAML errors can break playbooks   

YAML is readable, but mistakes in indentation could cause errors. Beginners should verify syntax before using playbooks.

Large environments need planning   

As automation expands the playbooks get become messy. Teams must use roles, collection, variables, and roles to ensure that automation is organized.

Real-time event handling needs extra tools

Basic Ansible is usually executed either manually or by scheduling workflows. Event-driven use cases require additional tools, like Event-Driven Ansible, or platform-level tools.

Secrets need proper handling

API keys and passwords should not be stored in plaintext. Ansible Vault or an appropriate secrets-management system must be utilized.

Network automation requires device-specific knowledge

Ansible can automate routers and switches, but engineers need to be aware of networking knowledge. A playbook can’t replace the knowledge of VLANs, ACLs, routing or the behavior of devices.

Ansible Best Practices for Beginners

Follow these best practices when learning Ansible:

• Start with small playbooks.
• Use clear task names.
• Keep inventory files organized.
• Store playbooks in Git.
• Use roles for reusable automation.
• Use variables instead of repeating values.
• Test playbooks in a lab first.
• Use Ansible Vault for sensitive data.
• Run playbooks with check mode before production changes.
• Document what each playbook does.

Good Ansible automation should be readable, reusable, and safe to run more than once.

How to Start Learning Ansible?

Beginners should not start by memorizing every module. They should follow a practical learning path.

Start with these skills:

1. Learn basic Linux commands.
2. Understand SSH and remote access.
3. Learn YAML syntax.
4. Build a simple inventory.
5. Run ad-hoc Ansible commands.
6. Create your first playbook.
7. Learn variables, handlers, and templates.
8. Organize playbooks with roles.
9. Practice Ansible for network automation.
10. Use Git to manage automation files.

For network engineers, the best path is slightly different. Learn Ansible basics first, and then practice device backup, show commands, VLAN configuration, and configuration validation in a lab.

Frequently Asked Questions

Conclusion

Ansible is an open-source tool for provisioning, application deployment, and configuration management that allows saving time, money, and effort by automating tasks across multiple servers. It is essential for developers and operations engineers to understand tools like these. Therefore, in this blog, we have discussed it in-depth, like what it is, how it works, what is Ansible used for, its features, its architecture, and its advantages and disadvantages. Do check out PyNet Labs’ Ansible and Terraform Course to master these tools.