docs: add ADR 0029 Tutor Implementation for authz schema discovery

[carlos-marquez-wgu]

Description

Adds ADR-0029 which defines how the Tutor implementation for authorization schema discovery works.

Authorization schema discovery already proposed a Tutor patch route in ADR 0019 and ADR 0023. This ADR fills the gap of how we feed the resulting authz schema YAML file to be discoverable.

The proposal includes adding a new Django setting for discovery to find the file, which needs to be an absolute filesystem path, and then using a Tutor plugin to place the rendered patch (openedx-authz-schema) where it can be found by this setting.

I also include two rejected alternatives: riding an existing installed package that Tutor already mounts files to, and scanning /openedx/config/ which already contains unrelated YAML configurations shipped by Tutor.

Key decisions

• Create a Tutor plugin in https://github.com/openedx/openedx-tutor-plugins
• Add new Django setting OPENEDX_AUTHZ_SCHEMA_FILES
• Treat schema resources as multi-document YAML streams so multiple plugin contributions survive concatenation
• Updates to discovery.py (filesystem paths) and loading.py (multi-document parsing)

Merge checklist:
Check off if complete or not applicable:

• Documentation updated (not only docstrings)
• Fixup commits are squashed away
• Unit tests added/updated
• Manual testing instructions provided
• Noted any: Concerns, dependencies, migration issues, deadlines, tickets

[openedx-webhooks]

Thanks for the pull request, @carlos-marquez-wgu!

This repository is currently maintained by @openedx/committers-openedx-authz.

Once you've gone through the following steps feel free to tag them in a comment and let them know that your changes are ready for engineering review.

🔘 Get product approval

If you haven't already, check this list to see if your contribution needs to go through the product review process.

• If it does, you'll need to submit a product proposal for your contribution, and have it reviewed by the Product Working Group.
  • This process (including the steps you'll need to take) is documented here.
• If it doesn't, simply proceed with the next step.

🔘 Provide context

To help your reviewers and other members of the community understand the purpose and larger context of your changes, feel free to add as much of the following information to the PR description as you can:

• Dependencies

  This PR must be merged before / after / at the same time as ...

• Blockers

  This PR is waiting for OEP-1234 to be accepted.

• Timeline information

  This PR must be merged by XX date because ...

• Partner information

  This is for a course on edx.org.

• Supporting documentation
• Relevant Open edX discussion forum threads

🔘 Get a green build

If one or more checks are failing, continue working on your changes until this is no longer the case and your build turns green.

Details

---

Where can I find more information?

If you'd like to get more details on all aspects of the review process for open source pull requests (OSPRs), check out the following resources:

• Overview of Review Process for Community Contributions
• Pull Request Status Guide
• Making changes to your pull request

When can I expect my changes to be merged?

Our goal is to get community contributions seen and reviewed as efficiently as possible.

However, the amount of time that it takes to review and merge a PR can vary significantly based on factors such as:

• The size and impact of the changes that it introduces
• The need for product review
• Maintenance status of the parent repository

💡 As a result it may take up to several weeks or months to complete a review and merge your PR.

[rodmgwgu]

I agree with this approach, thanks!

[BryanttV]

Thanks, @carlos-marquez-wgu! I just have a couple of comments.

we should update the ADR number, since 0028 is already taken.

[BryanttV]

An absolute-path schema file has no package or module. How would we obtain the (distribution, module, resource_path) source record that ADRs 0019 and 0025 require?

[carlos-marquez-wgu]

Good question

I propose we use a sentinel value for distribution and the absolute filesystem path for module and resource_path:

• distribution = <tutor-patch>
• module = the absolute path of the file
• resource_path = same absolute path (redundant for filesystem sources, but consistent with the model)
• distribution_version = 0.0.0 (Sentinel value - filesystem sources have no package version, and 0.0.0 signals that unambiguously.)

For our tutor plugin, the absolute path will be /openedx/config/authz-schema.yml, it works for identity because it's stable within a deployment, and it naturally extends if OPENEDX_AUTHZ_SCHEMA_FILES ever lists multiple files contributed by third party plugins / patches.

How does this sound?

pd: ADR number updated 😄