Ansible Modules: A Deep Dive

Are you tired of manually configuring your servers? Do you want to automate your infrastructure and save time? If so, Ansible is the tool for you. Ansible is an open-source automation tool that allows you to automate your IT infrastructure. It is easy to use, flexible, and powerful. One of the key features of Ansible is its modules. In this article, we will take a deep dive into Ansible modules and explore how they can help you automate your infrastructure.

What are Ansible Modules?

Ansible modules are small pieces of code that perform a specific task. They are the building blocks of Ansible playbooks. Modules can be used to manage files, install packages, configure services, and much more. Ansible comes with a large number of built-in modules, and you can also create your own custom modules.

How do Ansible Modules Work?

Ansible modules work by executing tasks on remote hosts. When you run an Ansible playbook, it sends the module code to the remote host and executes it. The module then performs the task and returns the result to the Ansible controller. Ansible modules are idempotent, which means that they can be run multiple times without changing the state of the system.

Types of Ansible Modules

Ansible modules can be divided into two types: core modules and custom modules.

Core Modules

Core modules are built-in modules that come with Ansible. They are maintained by the Ansible community and are included in the Ansible distribution. Core modules cover a wide range of tasks, including managing files, installing packages, configuring services, and more. Some examples of core modules include:

• copy: Copies files to remote hosts
• apt: Installs packages on Debian-based systems
• yum: Installs packages on Red Hat-based systems
• service: Manages services on remote hosts
• user: Manages users on remote hosts

Custom Modules

Custom modules are modules that you create yourself. They are written in Python and can be used to perform any task that is not covered by the core modules. Custom modules can be stored in a directory on the Ansible controller, and Ansible will automatically load them when you run a playbook. Some examples of custom modules include:

• my_module: A module that performs a custom task on remote hosts
• my_module2: Another module that performs a different custom task on remote hosts

How to Use Ansible Modules

Using Ansible modules is easy. You simply include the module name in your playbook, along with any necessary parameters. Here is an example of a playbook that uses the copy module to copy a file to remote hosts:

---
- name: Copy file to remote hosts
  hosts: web_servers
  tasks:
    - name: Copy file
      copy:
        src: /path/to/local/file
        dest: /path/to/remote/file

In this example, the copy module is used to copy a file from the local machine to remote hosts. The src parameter specifies the path to the local file, and the dest parameter specifies the path to the remote file.

Ansible Module Parameters

Ansible modules can take a variety of parameters, depending on the task they are performing. Some common parameters include:

• name: A name for the task
• state: The desired state of the system (e.g. present, absent)
• src: The source file or directory
• dest: The destination file or directory
• mode: The file permissions
• owner: The file owner
• group: The file group
• executable: Whether the file is executable
• args: Additional arguments to pass to the command

Ansible Module Return Values

When an Ansible module is executed, it returns a JSON object that contains information about the task. The return value can be used in subsequent tasks to perform conditional logic. The return value can contain the following keys:

• changed: Whether the state of the system was changed
• failed: Whether the task failed
• msg: A message describing the result of the task
• rc: The return code of the command
• stdout: The standard output of the command
• stderr: The standard error of the command

Ansible Module Development

If you need to perform a task that is not covered by the core modules, you can create your own custom module. Custom modules are written in Python and can be stored in a directory on the Ansible controller. Here is an example of a custom module that performs a task on remote hosts:

#!/usr/bin/python

from ansible.module_utils.basic import AnsibleModule

def main():
    module = AnsibleModule(
        argument_spec=dict(
            name=dict(required=True),
            age=dict(required=True, type='int'),
        )
    )

    name = module.params['name']
    age = module.params['age']

    result = dict(
        changed=False,
        message='Hello, {}! You are {} years old.'.format(name, age),
    )

    module.exit_json(**result)

if __name__ == '__main__':
    main()

In this example, the module takes two parameters (name and age) and returns a message that includes the values of those parameters. To use this module in a playbook, you would include the module name (my_module) in the playbook, along with the parameters:

---
- name: Use custom module
  hosts: web_servers
  tasks:
    - name: Run custom module
      my_module:
        name: John
        age: 30

Conclusion

Ansible modules are a powerful tool for automating your IT infrastructure. They allow you to perform a wide range of tasks, from managing files to configuring services. Ansible comes with a large number of built-in modules, and you can also create your own custom modules. By using Ansible modules, you can save time and reduce the risk of errors in your infrastructure. So why not give Ansible a try and see how it can help you automate your infrastructure today?

Editor Recommended Sites