grpc-ecosystem / grpc-gateway

🐛 Bug Report

Using the sample proto below, only default appears in the output json - example and pattern do not.

To Reproduce

message GetTileForImageRequest {
	// The unique reference number of the image.
	string image_urn = 1 [(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
		example: "urn:eagleview.com:v4:spatial-data:raster:visual:ated:QIgDbfZw-kqKfTxbMQXwhw:0",
		default: "urn:eagleview.com:v4:spatial-data:raster:visual:ated:QIgDbfZw-kqKfTxbMQXwhw:0",
		pattern: "^(urn:eagleview\\.com:v\\d+:spatial-data:\\w+:\\w+:\\w+:[A-Za-z0-9-_]+):(\\d+)$",
	}];
}

I'm using buf to generate the swagger using the following template:

buf.gen.swagger.yaml:

version: v1
plugins:
  - name: openapiv2
    out: build/go
    opt:
      - json_names_for_fields=false
      - visibility_restriction_selectors=LATEST

$ buf generate --template buf.gen.swagger.yaml --path proto/evt/iw/service

Expected behaviour

{
  "name": "image_urn",
  "description": "The unique reference number of the image.",
  "in": "path",
  "required": true,
  "type": "string",
  "example": "urn:eagleview.com:v4:spatial-data:raster:visual:ated:QIgDbfZw-kqKfTxbMQXwhw:0",
  "default": "urn:eagleview.com:v4:spatial-data:raster:visual:ated:QIgDbfZw-kqKfTxbMQXwhw:0",
  "pattern": "^(urn:eagleview\\.com:v\\d+:spatial-data:\\w+:\\w+:\\w+:[A-Za-z0-9-_]+):(\\d+)$"
}

Actual Behavior

{
  "name": "image_urn",
  "description": "The unique reference number of the image.",
  "in": "path",
  "required": true,
  "type": "string",
  "default": "urn:eagleview.com:v4:spatial-data:raster:visual:ated:QIgDbfZw-kqKfTxbMQXwhw:0"
}

Your Environment

$ uname -a
Linux 0664eeb787b5 5.14.0-1049-oem #56-Ubuntu SMP Fri Aug 12 10:23:08 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

$ protoc --version
libprotoc 25.3

Package	Version
github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway	v2.19.1
github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2	v2.19.1
google.golang.org/protobuf/cmd/protoc-gen-go	v1.32.0

Hm, that's odd, in our example protobuf file you can see that the example and pattern both make it into the generated file:

grpc-gateway/examples/internal/proto/examplepb/a_bit_of_everything.proto

Lines 193 to 202 in c2720cd

    
           message ErrorResponse { 
        
             string correlationId = 1 [(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = { 
        
               pattern: "^[0-9A-F]{8}-[0-9A-F]{4}-4[0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$", 
        
               title: "x-correlation-id", 
        
               description: "Unique event identifier for server requests", 
        
               format: "uuid", 
        
               example: "\"2438ac3c-37eb-4902-adef-ed16b4431030\"" 
        
             }]; 
        
             ErrorObject error = 2; 
        
           }

grpc-gateway/examples/internal/proto/examplepb/a_bit_of_everything.swagger.json

Lines 7795 to 7809 in c2720cd

    
           "examplepbErrorResponse": { 
        
             "type": "object", 
        
             "properties": { 
        
               "correlationId": { 
        
                 "type": "string", 
        
                 "format": "uuid", 
        
                 "example": "2438ac3c-37eb-4902-adef-ed16b4431030", 
        
                 "description": "Unique event identifier for server requests", 
        
                 "title": "x-correlation-id", 
        
                 "pattern": "^[0-9A-F]{8}-[0-9A-F]{4}-4[0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$" 
        
               }, 
        
               "error": { 
        
                 "$ref": "#/definitions/examplepbErrorObject" 
        
               } 
        
             }

Could you provide a test repo that reproduces the issue? Or better yet, make a contribution to our repo that exhibits the issue.

Please find attached a zip of a sample repo. that reproduces the issue.
imagery-warehouse-api-public-lite.zip

Thank you, with all due respect, I'm not going to download a zip file from a stranger on the internet. Could you please provide a github repository or gist or something where I can view the contents? Thanks.

I've created a private repo here, and have sent you an invite.

Sorry, that invitation expired, my bad, could you send it again please?

OK I can reproduce the issue. Seems like we only render the example when the field in question is used in the request body, not when it's part of the path or the query. I think we should be able to support including the example and other fields for non-body fields too.

Would you be interested in contributing a fix for this?