vars_prompt: add choices support for input validation

[bhowmickkrishnendu]

Summary

This PR adds support for a new choices key in vars_prompt, allowing list-based input validation directly in playbooks. Users can now restrict input to predefined options, improving playbook usability and preventing invalid data entry.

Feature

Example usage:

hosts: localhost
gather_facts: no
vars_prompt:
  - name: color
    prompt: "Choose a color"
    choices:
      - red
      - green
      - blue
    private: no

tasks:
  - debug:
      msg: "You selected: {{ color }}"

Behavior:

• If the user enters an invalid choice during interactive prompts, they are shown the valid options and prompted again.
• Values provided via --extra-vars are also validated against the choices list.
• If an invalid value is passed via --extra-vars, a ValueError is raised with a clear error message.

Example with --extra-vars:

Valid usage:

ansible-playbook playbook.yml --extra-vars "color=red"

Invalid usage (raises error):

ansible-playbook playbook.yml --extra-vars "color=yellow"

Error:

Invalid value for 'color': 'yellow' not in allowed choices ['red', 'green', 'blue']

Changes Made

• lib/ansible/playbook/play.py: Added 'choices' to the list of allowed keys in vars_prompt validation.

• lib/ansible/executor/playbook_executor.py:

  • Added logic to validate interactive user input against choices list.
  • Added validation for values provided via --extra-vars.
  • Implemented re-prompting logic when invalid choices are entered interactively.
  • Added clear error messages showing available options.

• changelogs/fragments/vars_prompt_choices_support.yml: Added changelog fragment documenting the new feature.

Notes

• Backward compatible: No changes to existing behavior unless choices is explicitly used.
• Enhanced UX: Clear error messages guide users to valid options.
• Comprehensive validation: Both interactive input and --extra-vars are validated.
• Useful for: Enforcing specific input options (e.g., environments, regions, deployment types).

ISSUE TYPE

• Feature Pull Request

Testing

Test interactive prompts with valid/invalid choices:

ansible-playbook test_choices.yml

Test --extra-vars validation with valid choice:

ansible-playbook test_choices.yml --extra-vars "color=red"

Test --extra-vars validation with invalid choice (should raise error):

ansible-playbook test_choices.yml --extra-vars "color=yellow"

[webknjaz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[webknjaz]

FYI this sort of change would normally require tests.

[bhowmickkrishnendu]

Thanks for the review! I’ve added integration tests under test/integration/targets/vars_prompt_choices/.

The tests cover:

• Valid choices via --extra-vars
• Invalid choices via --extra-vars (expected failure)

Please let me know if you’d like additional scenarios included.

[bhowmickkrishnendu]

This is long standing PR. Please verify!

[s-hertel]

Have you considered using a play argument spec instead? I'm not sure I see the benefit to adding 'choices' to 'vars_prompt' since the argument spec handles that and more.

For example:

# playbook.yml
- hosts: localhost
  gather_facts: no
  vars_prompt:
    - name: from_vars_prompt
      prompt: enter choice1 or choice2
  validate_argspec: vars_prompt_options

# playbook.meta.yml  - name must match playbook
argument_specs:
  vars_prompt_options:
    options:
      from_vars_prompt:
        type: str
        choices:
          - choice1
          - choice2
        required: True

[s-hertel]

What if choices is an unsupported format or contains invalid choices?

[s-hertel]

This seems like a change in behavior. Previously this occurred only iv the variable name is not in extra vars.

[s-hertel]

I don't think extra vars should be validated using choices.

[s-hertel]

If there's no valid choice this will loop forever. I think some validation of the contents of choices should be added first.

[bcoca]

@bhowmickkrishnendu stop spaming comments in other tickets, this is not a 'long standing PR' by any account, I could link hundreds that have been in the queue much longer.

[ansibot]

Hi @bhowmickkrishnendu!

Thank you very much for your submission to Ansible. It means a lot to us that you've taken the time to contribute.

Unfortunately, we currently ask that first-time contributors only have one open pull request. This will help you to learn what an acceptable pull request is like and also help us keep up with the review queue.

Since you already have an active pull request open at #85368, we are automatically closing this one for now. Once your other PR is merged or closed, please feel free to reopen this one or submit it again.

Thank you for understanding!

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