Refactor stub implementation of LTI Provider. BLD-601.

[olmar]

Refactor stub implementation of LTI Provider.

Issue: https://edx-wiki.atlassian.net/browse/BLD-601.

@auraz please review.
@wedaly please review.

[singingwolfboy]

Don't commit commented-out code to the repository.

[olmar]

@wedaly I`m looking for how it possible to launch such stubs manually. Do you know smth about it?

[wedaly]

The superclass defines a send_response method that accepts a headers kwarg. You should use that to send the headers.

[olmar]

Fixed.

[wedaly]

1. Take another look at the StubHttpService base class -- you can re-use the helper methods defined there instead of re-implementing them in the subclass.

2. I don't understand why the stub needs different configuration for unit/acceptance/manual testing. For unit tests, you should use mock.patch to mock requests.post. I don't understand why manual testing is handled as a separate case.

3. Please check for pylint/pep8 style violations.

4. Rebase onto master and resolve merge conflicts.

Please let me know when you're ready for me to take another look.

[wedaly]

In terms of starting the server manually, you can add a short Python script that starts the server on a particular port. I'd recommend adding this directly in common/djangoapps/terrain/stubs/lti.py for now. It should look something like this:

 if __name__ == "__main__":
     service = StubLtiService()
     service.start()
     try:
          while true:
               pass
     except KeyboardInterrupt:
          service.shutdown()
          exit(0)

[wedaly]

It looks like the LTI module is setting the hostname for the callback URL here:

https://github.com/edx/edx-platform/blob/master/common/lib/xmodule/xmodule/lti_module.py#L284-L299

It's setting it based on the XBlock's self.system.hostname property. This, in turn, looks like it's configured using Django settings:

https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/module_render.py#L391

We have SITE_NAME set to localhost in the sandbox, so it should be safe to change it to localhost in dev and devstack settings as well. I'd prefer to configure this in settings rather than within the stub server.

[olmar]

@wedaly please continue review.

[wedaly]

This looks like a private method; if so, it should have an underscore in front to denote that:

_create_content

[olmar]

made method to be private

[wedaly]

I made some style comments, and I'm still unsure about explicitly setting http/https for the test environment. You'll also need to rebase and fix merge conflicts.

Please let me know when you're ready for another round of review.

[olmar]

@auraz this PR involves some changes to LTI Module also. Please review.

[olmar]

@wedaly please continue review.

[wedaly]

👍 but please squash your commits before merging.

[auraz]

a) add comment why we do this
b) please remove changes to quoting