Making GAE_PYTHON optional in tox config.

[dhermes]

Fallback is ${GIT_ROOT}/google_appengine.

The goal is to also make these pull the latest version of the SDK (right now it is downloaded once and frozen in time).

[theacodes]

What was the issue with these commands being in tox, why did we have to move them to their own scripts?

[dhermes]

The issue is that GAE_PYTHONPATH is a requirement, rather than an optional flag that can be used to over-ride. Just running tox is not possible in a "clean" environment.

[theacodes]

You can make it optional by changing the substitution at line 40 from {env:GAE_PYTHONPATH} to {env:GAE_PYTHONPATH:/default/path}.

[theacodes]

(as an aside, I love tox but hate using an ini file for configuration)

[dhermes]

@jonparrott I am aware of the default via {env:VARNAME:DEFAULT_VAL} but

• was unclear on how to make this path relative to the root of the git repo
• am "future-proofing" by giving us a place to manually update the SDK when needed

[theacodes]

Fair enough, just wanted to make you aware of it. I'm fine with scripts as long as @nathanielmanistaatgoogle is fine with it.

Also, in terms of the GAE SDK - see https://github.com/GoogleCloudPlatform/python-repo-tools/blob/master/gcp_python_repo_tools/appengine_sdk.py - we're creating this in tandem with re-organizing the tests over at python-docs-samples. Eventually we should use that here to keep the SDK up-to-date (once I add updating functionality to it).

[dhermes]

Nice! I'm very happy to let you handle it.

[nathanielmanistaatgoogle]

As for my own being fine with scripts: uh... I really don't want to have to be. Look at the way this change adds so much more than it removes. How backed-into-a-corner are we?

[dhermes]

OK I nuked the scripts. There should still be some unification done in build_docs.sh and GAE_PYTHONPATH should be used with fetch_gae_sdk / update_gae_sdk in a consistent way.

[dhermes]

@jonparrott PTAL. It turns out a { inside of a { is a no-no. I tried {env:GAE_PYTHONPATH:{toxinidir}/google_appengine} and it failed in strange ways.

UPDATE: FWIW tox -e gae works perfectly fine from ${GIT_ROOT} or from ${GIT_ROOT}/tests or any other subdirector, meaning that the relative path is relative to {toxinidir} anyhow, so no-harm no-foul.

[theacodes]

Yeah toxinidir is almost always cwd, unless you explicitly change it.

[theacodes]

This LGTM.