Leveraging the Become Keyword in Ansible Task Scenarios

Introduction

This tutorial will guide you through the process of leveraging the "become" keyword in Ansible task scenarios. You will learn how to effectively utilize privilege escalation to execute your Ansible playbooks with elevated permissions, enabling you to automate a wide range of tasks and scenarios. By the end of this article, you will have a solid understanding of the "become" keyword and how to apply it in your Ansible projects.

Skills Graph

Introduction to Ansible and the Become Keyword

Ansible is a powerful open-source automation tool that simplifies the management of IT infrastructure and applications. At the core of Ansible's functionality is the concept of "tasks," which are the fundamental building blocks of Ansible playbooks. These tasks define the actions to be performed on remote hosts, such as installing software, configuring services, or managing user accounts.

One of the key features in Ansible is the become keyword, which allows you to execute tasks with elevated privileges. This is particularly useful when you need to perform actions that require administrative or root-level access, such as installing system packages, modifying system configurations, or managing sensitive files and directories.

In this section, we will explore the concept of privilege escalation in Ansible and dive into the details of the become keyword. We will discuss its purpose, configuration options, and practical examples to help you effectively leverage this feature in your Ansible-based automation workflows.

Understanding Privilege Escalation in Ansible Playbooks

Privilege Escalation in Ansible

Ansible, by default, executes tasks with the privileges of the user account that is running the Ansible command. However, many administrative tasks require elevated privileges, such as root or sudo access, to perform actions like installing software, modifying system configurations, or managing user accounts.

To address this requirement, Ansible provides the become keyword, which allows you to escalate the privileges of a task to a different user, typically the root user or a user with sudo permissions.

Become Keyword in Ansible

The become keyword in Ansible is used to specify the user account under which a task should be executed. This can be set at the playbook level, the task level, or even the host level, depending on your specific requirements.

When you use the become keyword, Ansible will attempt to escalate the privileges of the task to the specified user account. This can be done using various methods, such as sudo, su, or enable (for network devices).

- hosts: all
  become: true
  tasks:
    - name: Install package
      apt:
        name: nginx
        state: present
      become: true

In the example above, the become keyword is used at both the playbook level and the task level to ensure that the "Install package" task is executed with elevated privileges.

Become Options

Ansible provides several options to configure the become behavior, such as:

• become_user: The user account to switch to when executing the task.
• become_method: The privilege escalation method to use (e.g., sudo, su, enable).
• become_flags: Additional flags to pass to the privilege escalation method.

These options can be set at the playbook, task, or host level to fine-tune the privilege escalation process.

- hosts: all
  become: true
  become_method: sudo
  become_user: root
  tasks:
    - name: Install package
      apt:
        name: nginx
        state: present

In this example, the become_method is set to sudo, and the become_user is set to root, ensuring that the "Install package" task is executed with root privileges.

Leveraging the Become Keyword in Task Scenarios

Common Use Cases for the Become Keyword

The become keyword in Ansible is particularly useful in the following scenarios:

1. System Package Management: Installing, upgrading, or removing system packages often requires elevated privileges. Using the become keyword ensures that these tasks can be executed successfully.

2. System Configuration Management: Modifying system-level configurations, such as network settings, firewall rules, or service configurations, typically requires root or sudo access. The become keyword enables you to make these changes programmatically.

3. User and Group Management: Creating, modifying, or deleting user accounts and groups often requires administrative privileges. The become keyword allows you to automate these user management tasks.

4. File and Directory Operations: Performing operations on sensitive files and directories, such as modifying permissions, ownership, or content, may require elevated privileges. The become keyword ensures that these file-related tasks can be executed as needed.

5. Service Management: Starting, stopping, or restarting critical system services, such as web servers, database engines, or network daemons, often requires root or sudo access. The become keyword enables you to manage these services programmatically.

Practical Examples

Here are some practical examples of using the become keyword in Ansible playbooks:

- hosts: webservers
  become: true
  tasks:
    - name: Install Apache web server
      apt:
        name: apache2
        state: present

    - name: Start Apache service
      systemd:
        name: apache2
        state: started
        enabled: true

- hosts: dbservers
  become: true
  become_user: postgres
  tasks:
    - name: Create a new PostgreSQL database
      postgresql_db:
        name: myapp_db

    - name: Create a new PostgreSQL user
      postgresql_user:
        name: myapp_user
        password: mypassword

In the first example, the become keyword is used at the playbook level to execute all tasks with elevated privileges. This ensures that the Apache web server can be installed and the service can be started successfully.

In the second example, the become keyword is used at the playbook level, and the become_user option is set to postgres. This allows the tasks to be executed with the privileges of the postgres user, which is necessary for managing PostgreSQL databases and users.

By leveraging the become keyword in your Ansible playbooks, you can seamlessly execute tasks that require elevated privileges, simplifying your automation workflows and ensuring the successful completion of critical system management operations.

Configuring the Become Keyword and Available Options

Configuring the Become Keyword

The become keyword in Ansible can be configured at various levels, including the playbook, task, and host level. This flexibility allows you to fine-tune the privilege escalation behavior based on your specific requirements.

Here's an example of how you can configure the become keyword at different levels:

## Playbook-level configuration
- hosts: all
  become: true
  become_method: sudo
  become_user: root

  tasks:
    - name: Install package
      apt:
        name: nginx
        state: present

    - name: Start nginx service
      systemd:
        name: nginx
        state: started
      become: true
      become_user: nginx

In this example, the become keyword is set at the playbook level, which means that all tasks will be executed with elevated privileges. The become_method is set to sudo, and the become_user is set to root, indicating that the tasks should be executed as the root user using the sudo command.

However, for the "Start nginx service" task, the become keyword is set at the task level, overriding the playbook-level configuration. In this case, the task will be executed as the nginx user, which is necessary to start the Nginx service.

Available Become Options

Ansible provides several options to configure the become behavior, which can be set at the playbook, task, or host level. These options include:

These options can be used in combination to customize the become behavior to suit your specific needs. For example, you might need to use a different privilege escalation method or provide a specific user account for certain tasks or playbooks.

By understanding how to configure the become keyword and its available options, you can leverage the power of Ansible's privilege escalation features to automate a wide range of system administration tasks effectively.

Practical Examples and Use Cases for the Become Keyword

Managing System Packages

One of the most common use cases for the become keyword is managing system packages. This includes installing, upgrading, or removing packages that require elevated privileges. Here's an example:

- hosts: webservers
  become: true
  tasks:
    - name: Install Apache web server
      apt:
        name: apache2
        state: present
    - name: Start Apache service
      systemd:
        name: apache2
        state: started
        enabled: true

In this example, the become keyword is used at the playbook level to ensure that the tasks of installing the Apache web server and starting the Apache service are executed with elevated privileges.

Configuring System Settings

Another common use case for the become keyword is modifying system-level configurations, such as network settings, firewall rules, or service configurations. These tasks often require administrative access to the system. Here's an example:

- hosts: firewalls
  become: true
  tasks:
    - name: Open port 80 in the firewall
      ufw:
        rule: allow
        port: "80"
    - name: Open port 443 in the firewall
      ufw:
        rule: allow
        port: "443"

In this example, the become keyword is used to execute the tasks of opening ports 80 and 443 in the firewall, which requires elevated privileges.

Managing User Accounts

The become keyword can also be used to automate the management of user accounts, such as creating, modifying, or deleting users and groups. This is particularly useful when you need to provision new user accounts or maintain existing ones. Here's an example:

- hosts: all
  become: true
  tasks:
    - name: Create a new user
      user:
        name: myapp_user
        groups: sudo
        shell: /bin/bash
    - name: Set a password for the new user
      user:
        name: myapp_user
        password: "$6$rounds=656000$XiI67Uj1Zq$Uo5Xq8DjRh6URiA8Fj/HnFQ7731cXvIVFvKhmaAlmZI9Dc8u/P9KWLXQrG7nztTCj0KMfQ.9rKHGTXhgO0"

In this example, the become keyword is used to create a new user account with the sudo group membership and set a password for the new user.

By exploring these practical examples, you can see how the become keyword can be leveraged in various Ansible use cases to automate tasks that require elevated privileges, streamlining your infrastructure management and deployment processes.

Summary

In this comprehensive tutorial, you have learned how to leverage the "become" keyword in Ansible task scenarios. You now understand the importance of privilege escalation, how to configure the "become" keyword, and explore practical examples and use cases. By mastering the "become" keyword, you can unlock the full potential of your Ansible automation, ensuring seamless execution of tasks and enhancing the overall efficiency of your infrastructure management.