Add 'validate' regex support for vars_prompt

[bhowmickkrishnendu]

Summary

This PR adds support for a new validate key in vars_prompt, allowing regex-based input validation directly in playbooks.

Feature

Example usage:

- hosts: localhost
  gather_facts: no
  vars_prompt:
    - name: phone
      prompt: "Enter your 10-digit phone number"
      validate: "^[0-9]{10}$"
      private: no

  tasks:
    - debug:
        msg: "You entered: {{ phone }}"

If the user input does not match the regex, they are prompted again until the input is valid.

Changes Made

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

lib/ansible/executor/playbook_executor.py: Added logic to evaluate the regex and reprompt on failure.

Notes

Backward compatible: no changes to existing behavior unless validate is explicitly used.
Useful for enforcing specific input formats (e.g., phone numbers, IPs, usernames).

ISSUE TYPE

• Feature Pull Request

[ansibot]

The test ansible-test sanity --test pep8 [explain] failed with 1 error:

lib/ansible/executor/playbook_executor.py:152:161: E501: line too long (161 > 160 characters)

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[bhowmickkrishnendu]

@felixfontein

[felixfontein]

@bhowmickkrishnendu why are you pining me in this PR?

[bhowmickkrishnendu]

@bhowmickkrishnendu why are you pining me in this PR?

Hi @felixfontein , apologies for tagging you directly — I wasn’t aware of the review workflow in the Ansible community and was just trying to request feedback from someone experienced. Thank you for pointing it out!

I’ll follow the standard process and wait for maintainers or codeowners to review this PR. Appreciate your time and support!

[felixfontein]

The core team usually goes through all (new) PRs once or twice a week, I think, but usually not on weekends.

[bhowmickkrishnendu]

The core team usually goes through all (new) PRs once or twice a week, I think, but usually not on weekends.

Thanks for the clarification, @felixfontein — that’s really helpful. I’ll wait patiently for the core team to review it during the usual cycle. Appreciate your time!

[bcoca]

how would this interact with overriding extra vars?

also, using assert/fail seems like a more complete solution

[bhowmickkrishnendu]

how would this interact with overriding extra vars?

also, using assert/fail seems like a more complete solution

Thanks @bcoca — excellent points!

I tested the behavior with --extra-vars, and found that the prompt is still triggered even if the variable is already passed. I plan to update the logic to skip prompting and validation if the variable is already set, ensuring it behaves consistently with other Ansible variable precedence rules.

Regarding assert/fail, my intent was to bring regex validation closer to the input stage itself — allowing early feedback during prompts, before the play begins. But I totally understand your point, and am open to feedback if there's a preferred way you'd like this handled.

I’ll push a patch shortly with the fix for --extra-vars. Appreciate your review and guidance!

[bhowmickkrishnendu]

@bcoca Thanks for the suggestion! Now validation also applies to values passed via --extra-vars or other sources. If the input doesn't match the validate: regex, it raises an error and avoids prompting.

[bhowmickkrishnendu]

Rebased with latest devel to keep CI up-to-date. Looking forward to review feedback!

[bhowmickkrishnendu]

All requested changes are now complete, and I've added the changelog fragment as per the contribution guidelines.
This PR is ready for review. Thank you!

[webknjaz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[bhowmickkrishnendu]

Hi team 👋 Just checking in — it’s been a couple of weeks since /azp run, and the stale_ci label is now showing. Let me know if I should rebase or re-trigger CI. Happy to adjust anything needed 🙌