golang: refresh dask-gateway-proxy using modules and package directories

[rigzba21]

@consideRatio Restructuring dask-gateway-proxy using go project layout to address #506

Nothing has changed as far as functionality.

• Both router.go and sni.go have been moved into separate packages under the pkg/ directory.
• main.go has been moved to cmd/dask-gateway-proxy.
• logging.go has been moved to its own internal package under internal/logging.
• Generated a new go.mod and go.sum with dependencies.
• GitHub Actions updated to point to pkg/, cmd/dask-gateway-proxy/, and internal/.
  • Currently there are only unit tests for pkg/router.

I hope this helps!

---

EDIT: closes #506!

[consideRatio]

Thank you for your work on this @rigzba21!!! From what I can tell, this looks good. I left a few comments for my own insight but this LGTM from what I can tell.

Also note that the test failures are unrelated at least to this PR (ipython/traitlets#731).

[consideRatio]

@martindurant @TomAugspurger @jacobtomlinson a ping for review, i figure we merge this soonish without further comments.

[TomAugspurger]

I've never written go before, but +1 to the goals of this PR.

[jacobtomlinson]

This seems like a great move to me. The only comment I have is why are we putting some code under pkg? I don't think we should be intentionally exposing any public APIs and we should probably place it in internal instead.

[rigzba21]

The only comment I have is why are we putting some code under pkg? I don't think we should be intentionally exposing any public APIs and we should probably place it in internal instead.

I thought about that, however, I figured that might be a design decision outside of the scope of this PR, and might fit better in a separate PR, and I do not have as much context into the long-term goals for dask-gateway-proxy.

[consideRatio]

I figured that might be a design decision outside of the scope of this PR, and might fit better in a separate PR

Deal! Let's go for a merge on this. The tests were passing before we ran into an issue I think was related to traitlets (ipython/traitlets#731).

[consideRatio]

@rigzba21 thank you so much for your work on this!!!!!! 🎉 ❤️ 🌻