readme.md

Lab: Using the Assert Module with Input in Ansible

Overview

In this lab, you will learn how to use the assert module in Ansible to validate user input. By prompting the user for input and asserting conditions against the provided values, you can ensure your playbooks are interactive and error-proof.

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Objectives

• Learn how to use the assert module to validate input.
• Prompt for user input using vars_prompt.
• Ensure playbook tasks execute only when valid inputs are provided.

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Prerequisites

• Basic understanding of Ansible playbooks.
• Ansible installed on your ansible machine.

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Duration

Estimated Time: 20 minutes

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Instructions

Step 1: Set Up the Ansible Playbook

1. Create a new YAML file named assert_input_example.yml.

2. Define the play's name, target hosts (localhost in this case), and whether to gather facts:

   ---
   - name: Demonstrate Assert with User Input
     hosts: localhost
     gather_facts: no

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Step 2: Prompt for User Input

1. Add a vars_prompt section to collect a number from the user:

     vars_prompt:
       - name: "user_number"
         prompt: "Please enter a number between 1 and 10"
         private: no

   Explanation:

   • vars_prompt prompts the user for input when the playbook is executed.
   • The input is stored in the user_number variable.

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Step 3: Assert the User Input

1. Add a task to validate that the number entered by the user is within the range 1 to 10:

     tasks:
       - name: Assert that the number is between 1 and 10
         assert:
           that:
             - user_number | int >= 1
             - user_number | int <= 10
           fail_msg: "The entered number is not between 1 and 10"
           success_msg: "The entered number is valid. Proceeding..."

   Explanation:

   • The assert module validates conditions defined in the that list.
   • If the conditions fail, the playbook halts and displays the fail_msg.
   • If the conditions pass, the success_msg is shown.

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Step 4: Display a Success Message

1. Add a task to display a message confirming successful input validation:

       - name: Display a success message
         debug:
           msg: "You've successfully entered a valid number. Thank you!"

   Explanation:

   • The debug module displays a custom success message if the input passes validation.

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Step 5: Execute the Playbook

1. Save the assert_input_example.yml file.

2. Run the playbook using the following command:

   ansible-playbook assert_input_example.yml

3. Follow the prompt to enter a number. If the number is outside the range 1-10, the playbook will halt with an assertion failure message.

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Conclusion

In this lab, you've learned how to use the assert module in Ansible to validate user input dynamically. This approach ensures your playbooks remain interactive, adaptable, and resilient to incorrect inputs. By incorporating input validation, you can create more reliable and user-friendly playbooks. Keep experimenting to further enhance your automation workflows! 👏