Ansible is an open-source automation tool that is used for configuration management, application deployment, task automation, and orchestrating complex workflows in IT environments. It simplifies the process of managing and maintaining servers, infrastructure, and applications by allowing you to define tasks and configurations in a declarative manner.
Here are some key characteristics and features of Ansible:
- Agentless: One of Ansible’s notable features is that it is agentless, which means it doesn’t require any software or agents to be installed on the target systems you want to manage. Instead, it uses SSH (for Linux/Unix systems) or WinRM (for Windows systems) to communicate and execute tasks remotely.
- Declarative Language: Ansible uses a declarative language to define the desired state of a system or application. You specify what you want the system to look like, and Ansible figures out how to make it happen.
- Playbooks: Ansible configurations and automation tasks are defined in Playbooks. Playbooks are written in YAML and contain a series of tasks, each describing a specific action to be performed on target systems. These tasks can include package installation, file copying, service management, and more.
- Idempotent: Ansible playbooks and tasks are designed to be idempotent, meaning they can be run multiple times without causing unintended changes. If the desired state has already been achieved, Ansible won’t make any changes, which helps ensure the stability of your systems.
- Extensible: Ansible can be easily extended through custom modules and plugins. You can write custom modules in various programming languages to integrate Ansible with your specific applications and services.
- Inventory Management: Ansible uses an inventory file to specify the list of hosts or systems it should manage. The inventory file can be static or dynamic, allowing you to automate tasks across a wide range of hosts.
- Roles: Ansible roles provide a way to organise and reuse Playbook content. Roles are like building blocks that encapsulate specific functionality and can be shared and reused across projects.
- Ad-Hoc Commands: In addition to Playbooks, Ansible allows you to run ad-hoc commands directly from the command line, making it useful for quick tasks or troubleshooting.
- Community and Ecosystem: Ansible has a vibrant community that actively contributes to its development. It also has a rich ecosystem of pre-built roles and modules available on Ansible Galaxy, which can save time and effort when automating common tasks.
Ansible is widely used in DevOps and system administration for automating repetitive tasks, ensuring consistency across environments, and managing infrastructure as code. It is a versatile tool that can be applied to a wide range of use cases, from server provisioning and configuration management to application deployment and cloud orchestration.
Steps to setup ansible server
Setting up an Ansible server involves a few key steps to get you started with using Ansible to manage remote systems. Here’s a high-level overview of the steps to set up an Ansible server:
- Choose Your Server:
– Select a server or machine (physical or virtual) that will act as your Ansible control node. This is where you’ll install and run Ansible from.
- Install Ansible:
– Install Ansible on your control node. Ansible is typically available for Linux distributions, macOS, and Windows Subsystem for Linux (WSL). You can use package managers like
`apt`, `yum`:
- Verify Installation:
– After installation, you can verify Ansible is installed correctly by running:
- Create an Inventory File:
– Create an Ansible inventory file (sometimes referred to as the hosts file) to specify the target systems or hosts you want to manage with Ansible. This file typically resides at
`/etc/ansible/hosts` or a custom location.
Example inventory file (`/etc/ansible/hosts`):
- Set Up SSH Key-Based Authentication:
– To allow Ansible to securely communicate with your target systems, set up SSH
key-based authentication between the Ansible control node and the target systems. Ensure that the SSH public key of your control node is added to the `~/.ssh/authorized_keys` file on each target system.
- Test SSH Connectivity:
– Verify that Ansible can connect to your target systems using SSH. You can do this with the `ansible` command:
This command sends a ping to all the hosts in your inventory to check if they are reachable.
- Write Ansible Playbooks:
– Create Ansible Playbooks to define the tasks and configurations you want to automate on your target systems. Playbooks are written in YAML and describe the desired state of your systems.
- Run Ansible Playbooks:
– Execute Ansible Playbooks to apply configurations and automate tasks on your target systems. You can run a playbook using the `ansible-playbook` command:
- Monitor and Manage:
– Regularly monitor and manage your systems using Ansible by running playbooks as needed. Ansible keeps systems in the desired state defined in your playbooks.
These steps provide a basic overview of setting up an Ansible server and getting started with automation.