Ansible 101

In today’s fast-paced business environment, automation is key to staying ahead of the competition. One tool that can help you achieve this is Ansible. Ansible is an open-source automation tool that simplifies the process of configuring and managing systems, deploying applications, and automating repetitive tasks. In this blog post, we will take a closer look at what Ansible is, its components, how it can be used in playbooks, and how it fits into a DevOps CICD workflow.

What is Ansible?

Ansible is an open-source automation tool that helps in the configuration management and application deployment of systems. It allows you to automate repetitive tasks, deploy applications, and manage infrastructure in a simple and efficient way. It uses a simple, human-readable language (YAML) to describe automation jobs, called Playbooks, which are executed against one or many systems. Ansible works by connecting to your nodes and pushing out small programs, called “Ansible modules” to them. These programs are written to be resource models of the desired state of the system. Ansible then executes these modules (over SSH by default), and removes them when finished.

Ansible is different from other automation tools in that it is agentless, meaning that it doesn’t require any additional software to be installed on the target systems. Instead, it uses SSH to communicate with the systems it manages, making it easy to set up and use.

It can be used for a wide variety of tasks, including:

• Configuring and managing servers
• Deploying and scaling applications
• Automating repetitive tasks
• Managing and provisioning cloud resources
• Managing and configuring network devices

Ansible also has a large and active community, which means that there are many resources available for learning and troubleshooting. It is supported on a wide range of operating systems, including Linux, Unix, and Windows.

Overall, Ansible is a powerful and easy-to-use automation tool that can help you streamline your operations and improve your workflow. It’s a great choice for anyone looking to automate their systems and infrastructure.

What are Anisble components?

Ansible has several components that work together to make automation possible. These include:

• Modules: These are the building blocks of Ansible that allow you to perform various tasks on your systems. Some examples of modules include file, command, and service.

• Playbooks: These are the files that contain the instructions for Ansible to execute. They are written in YAML and describe the tasks to be performed, the systems to be targeted, and the order in which the tasks should be executed.

• Inventory: This is a file that contains a list of the systems that Ansible should manage. It can be a simple text file or a more advanced file that can be dynamically generated.

• Variables: Ansible allows you to use variables in playbooks to make them more flexible and reusable. These variables can be defined in the playbook or in separate files.

What is Anisble playbook?

An Ansible playbook is a file that defines a set of tasks to be executed on a specified set of hosts. The playbook is written in YAML and is used to automate the deployment and configuration of systems.

A playbook typically contains one or more plays, each of which defines a specific set of tasks to be executed on a specific group of hosts. Each play contains a list of tasks, which are executed in the order they are defined. Tasks can be simple shell commands or more advanced operations, such as installing software or configuring services.

An example Ansible playbook that installs Apache web server on all hosts defined in the inventory file might look like this:

---
- name: Install Apache Web Server
  hosts: all
  tasks:
  - name: Install Apache
    yum: name=httpd state=installed
  - name: Start Apache
    service: name=httpd state=started

In this example, the playbook is named “Install Apache Web Server” and targets all hosts defined in the inventory file. The tasks to be executed are to install Apache and start the Apache service.

Playbooks can also include variables, which can be used to make the playbook more flexible and reusable. Variables can be defined in the playbook itself or in separate files, and can be used to specify things like the version of software to install or the location of configuration files.

Ansible playbooks are an essential part of Ansible automation, and are used to deploy and manage infrastructure in a simple and efficient way. They can be executed on the command line or integrated into a continuous integration and continuous deployment (CI/CD) pipeline, allowing for automated, repeatable deployments.

What are Ansible roles?

Ansible roles are a way to organize and structure your Ansible playbooks by breaking them down into smaller, reusable units. A role is a collection of tasks, files, templates, and variables that are organized in a specific directory structure.

Roles are defined in the roles directory and are made up of the following directories and files:

• tasks: This directory contains the main.yml file that defines the tasks to be executed by the role
• files: This directory contains any files that need to be copied to the target systems
• templates: This directory contains any templates that need to be rendered and copied to the target systems
• vars: This directory contains any variables used by the role
• defaults: This directory contains default values for variables
• meta: This directory contains metadata about the role, such as its name and dependencies

An example Ansible role that installs and configures the Apache web server might have the following directory structure:

roles/
    apache/
        tasks/
            main.yml
        files/
            httpd.conf
        templates/
            index.html.j2
        vars/
            main.yml
        defaults/
            main.yml
        meta/
            main.yml

The main.yml file in the tasks directory might look like this:

---
- name: Install Apache
  yum: name=httpd state=installed
- name: Start Apache
  service: name=httpd state=started
- name: Copy Apache Configuration
  copy: src=files/httpd.conf dest=/etc/httpd/conf/httpd.conf
- name: Copy index page
  template: src=templates/index.html.j2 dest=/var/www/html/index.html

In this example, the role is named “Apache” and it installs the Apache web server, starts the Apache service, copies the Apache configuration file and index page, allowing user to customize the index page.

Roles can then be included in playbooks using the roles keyword, like this:

---
- name: Example playbook
  hosts: all
  roles:
  - apache

In this way, Ansible roles allow you to organize and reuse your playbooks, making them more maintainable and easier to understand. Roles can also be shared and reused across different playbooks and projects, making it a powerful feature of Ansible.

How Ansible fits in DevOps CICD?

Ansible fits well into a DevOps CICD (Continuous Integration and Continuous Deployment) workflow as it allows for automation of repetitive tasks and infrastructure management, making the deployment process more efficient and less error-prone. Ansible playbooks can be integrated into your CI/CD pipeline and executed automatically on your systems, ensuring that your applications are always up to date and running smoothly.