protoc-gen-swagger: support JSON Schema Validation properties and add openapiv2_field option

[co3k]

This change supports JSON Schema Validation properties.
It allows you to specify some validation rules in .proto file like this:

message GeoCoordinate {
  option (grpc.gateway.protoc_gen_swagger.options.openapiv2_schema) = {
    json_schema: {
      required: ["latitude", "longitude"]
    }
  };

  string latitude = 1;
  string longitude = 2;
}

And also this supports openapiv2_field field option.
It allows you to specifiy additional JSON schema setting like this:

string latitude = 1 [(grpc.gateway.protoc_gen_swagger.options.openapiv2_field) = {pattern: "^[\-]?[0-9]{0,2}\.[0-9]+$"}];
string longitude = 2 [(grpc.gateway.protoc_gen_swagger.options.openapiv2_field) = {pattern: "^[\-]?[0-9]{0,3}\.[0-9]+$"}];

The both of grpc.gateway.protoc_gen_swagger.options.openapiv2_schema and grpc.gateway.protoc_gen_swagger.options.openapiv2_field now supports the following validation properties.

• multiple_of
• maximum
• exclusive_maximum
• minimum
• exclusive_minimum
• max_length
• min_length
• pattern
• max_items
• min_items
• unique_items
• max_properties
• min_properties
• required

Please see also JSON Schema Validation spec to understand about these properties.

[codecov-io]

Codecov Report

Merging #687 into master will decrease coverage by 0.13%.
The diff coverage is 39.06%.

@@            Coverage Diff             @@
##           master     #687      +/-   ##
==========================================
- Coverage    56.3%   56.16%   -0.14%     
==========================================
  Files          30       30              
  Lines        3062     3112      +50     
==========================================
+ Hits         1724     1748      +24     
- Misses       1167     1193      +26     
  Partials      171      171

Impacted Files	Coverage Δ
protoc-gen-swagger/genswagger/types.go	19.04% <ø> (ø)	⬆️
protoc-gen-swagger/genswagger/template.go	38.75% <39.06%> (+0.57%)	⬆️

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[co3k]

Hi, I really need these changes for my works but there aren't any reactions for a month.
What should I do to get any feedbacks about this pull request?

[johanbrandhorst]

This is really interesting, but to make things easier for us maintainers, could you please include a description of the changes? Include any external links as well.

[co3k]

@johanbrandhorst Thanks for your advice! I've added descriptions to this pull request. If it's OK, I will also change the commit message to follow it.

[johanbrandhorst]

@co3k that's great thanks! I think this looks good but I would like the input of @ivucica as well before we merge.

[ivucica]

Can't think of a better way to go about it. I would just rename the new option, but otherwise this seems to be it.

[ivucica]

Can we name this just openapiv2_field similar to what was done with other options?

[co3k]

I've fixed it in 48e32c9

[co3k]

I wonder why the Go: 1.10.x GATEWAY_PLUGIN_FLAGS= Travis CI build gets failed after my rebasing. I've tried make realclean examples but this problem isn't solved.

[johanbrandhorst]

@co3k There's definitely something weird up with our CI pipeline at the moment, I'm trying to work out with the other maintainers what we need to do, sorry for the inconvenience. We'll get this change in as soon as possible!

[co3k]

Oh, I'm sorry...I've forgotten to do go get -u github.com/golang/protobuf/protoc-gen-go before my local building.

Finally, Travis CI builds have been passed.

[johanbrandhorst]

go get -u github.com/golang/protobuf/protoc-gen-go

You absolutely should not be expected to do this. Install it from the vendor folder: go install ./vendor/github.com/golang/protobuf/protoc-gen-go

[johanbrandhorst]

Thanks for your contribution!

[achew22]

@johanbrandhorst would it be possible to have the Makefile build protoc-gen-go from the vendor directory and use it instead?

[johanbrandhorst]

@achew22 This was part of the change I made already:

grpc-gateway/Makefile

Line 119 in 221ef34

go install ./vendor/$(GO_PLUGIN_PKG)