Support colon in final path segment, last match wins behavior (behind flags)

[jfhamlin]

Addresses #224. Reintroduces changes from #708, this time behind a command line flag (-allow_colon_final_segments) and adds a new option to runtime.ServeMux to enable "last match wins" behavior. Please see discussion in #224 and #708 for context.

[johanbrandhorst]

Hi @jfhamlin, thanks for the contribution! Looks like you need to regenerate some of the example files, please see CONTRIBUTING.md for two docker one liners you can run.

[jfhamlin]

please see CONTRIBUTING.md for two docker one liners you can run.

Done!

[codecov-io]

Codecov Report

Merging #949 into master will increase coverage by 0.17%.
The diff coverage is 82.05%.

@@            Coverage Diff             @@
##           master     #949      +/-   ##
==========================================
+ Coverage   53.06%   53.23%   +0.17%     
==========================================
  Files          40       40              
  Lines        3969     3999      +30     
==========================================
+ Hits         2106     2129      +23     
- Misses       1667     1672       +5     
- Partials      196      198       +2

Impacted Files	Coverage Δ
protoc-gen-grpc-gateway/descriptor/registry.go	58.77% <0%> (-1.05%)	⬇️
runtime/mux.go	55.38% <100%> (+2.15%)	⬆️
protoc-gen-grpc-gateway/gengateway/template.go	67.03% <100%> (+1.51%)	⬆️
runtime/pattern.go	90.38% <87.5%> (-1.05%)	⬇️

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[johanbrandhorst]

LGTM, thanks for this brilliant contribution!

[aysylu]

This appears to be breaking existing projects with:

proto/v1beta1/project_go_proto/project.pb.gw.go:244:75: too many arguments in call to runtime.NewPattern
proto/v1beta1/project_go_proto/project.pb.gw.go:244:135: undefined: runtime.AssumeColonVerbOpt

Test link: https://circleci.com/gh/grafeas/grafeas/1066?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-build-link. Could you provide some insight into what's broken?

[johanbrandhorst]

@aysylu I've just released 1.9.2, which should fix your build. As a general note, the error you're getting is because you're using the master version of the generator (protoc-gen-grpc-gateway), and a locked version of the runtime. Ideally, these should always be the same version. In reality, we know this confuses a lot of users, so please update to 1.9.2 and it should fix your issue.

[aysylu]

@johanbrandhorst we were able to get around the issue updating our config and pointing to 1.9.0. We did test whether 1.9.2 and it looks like it fails with the same issue, just an FYI. Happy to provide more information on the dependencies if it's helpful.

[johanbrandhorst]

Hm, how are you generating the files and versioning the runtime? I'd be very interested in hearing of 1.9.2 is broken.