How to reuse scripts across multiple playbooks?

Reusing Scripts Across Multiple Playbooks

Ansible is a powerful automation tool that allows you to manage your infrastructure and applications across multiple hosts. When working with Ansible, you may find yourself needing to reuse the same scripts or tasks across multiple playbooks. This can help you save time, reduce code duplication, and improve the maintainability of your Ansible codebase.

Shared Roles

One of the best ways to reuse scripts in Ansible is through the use of shared roles. Roles are a way to encapsulate related tasks, files, templates, and variables into a reusable package. By creating a shared role, you can make it available to multiple playbooks, ensuring that the same logic is applied consistently across your infrastructure.

Here's an example of how you can create a shared role:

In this example, we have an Ansible project with a roles directory. Inside the roles directory, we have a common role that contains various subdirectories, such as tasks, files, templates, vars, defaults, and meta. These subdirectories allow you to organize your role's components, making it easier to maintain and reuse across multiple playbooks.

To use the shared role in your playbooks, you can simply include it as a dependency:

- hosts: all
  roles:
    - common

This will execute all the tasks, files, and templates defined within the common role.

Shared Modules and Plugins

In addition to shared roles, Ansible also supports the creation of custom modules and plugins. These can be used to encapsulate complex logic or functionality that can be reused across multiple playbooks.

To create a shared module or plugin, you can place it in a centralized location, such as the library or filter_plugins directories within your Ansible project. Then, you can reference the module or plugin in your playbooks, just like you would with any other Ansible module or plugin.

Here's an example of how you might use a custom module in your playbook:

- hosts: all
  tasks:
    - name: Perform a custom action
      my_custom_module:
        param1: value1
        param2: value2
      register: result

By creating and sharing custom modules and plugins, you can further extend the functionality of Ansible and make your playbooks more reusable and maintainable.

Shared Variables and Templates

Another way to reuse scripts across multiple playbooks is through the use of shared variables and templates. Ansible allows you to define variables at various levels, such as the host, group, or even the entire playbook level. By centralizing the definition of these variables, you can ensure consistency and make it easier to update values across multiple playbooks.

Similarly, Jinja2 templates can be shared and reused across multiple playbooks. This can be particularly useful for generating configuration files or other dynamic content that needs to be applied consistently across your infrastructure.

Here's an example of how you might use a shared template in your playbook:

- hosts: all
  tasks:
    - name: Render a configuration file
      template:
        src: config.j2
        dest: /etc/myapp/config.conf

By using shared variables and templates, you can further promote reusability and maintainability in your Ansible codebase.

Conclusion

Reusing scripts across multiple Ansible playbooks is an important aspect of building scalable and maintainable infrastructure automation. By leveraging shared roles, custom modules and plugins, and shared variables and templates, you can create a more modular and flexible Ansible codebase that can adapt to changing requirements and reduce the overall effort required to manage your infrastructure.

Remember, the key to effective script reuse in Ansible is to focus on creating well-designed, modular components that can be easily shared and updated across your organization. By following these best practices, you can streamline your Ansible workflows and ensure that your infrastructure automation efforts are efficient and sustainable.