Adding custom mux endpoint to openapi output

[joshgarnett]

Adding custom mux endpoint to openapi output

[johanbrandhorst]

As Kamesh says, this is a post-processing step at the moment, there's no support for including it in the output generated by protoc-gen-openapiv2. I think Kamesh is talking about using https://jsonpatch.com/ perhaps? But any way you want to post-process the file should work. I've used Go before.

[kamesh-09]

You can have a json file similar to openapi output - having paths as key - with upload endpoints. Once openapi output is generated you can patch your custom file into generated output. Can be automated via script which will basically combine both json files, so manual update is not required everytime.

You can define patch file as:

{
  "paths": {
    "upload_endpoint": {
      "methodType[post]": {
        "requestBody": {.....}
      }
    }
  }
}

[joshgarnett]

For anyone else going down this path, here is an example patch file you can use:

{
  "paths": {
    "/v1/file": {
      "post": {
        "summary": "Upload a file",
        "operationId": "Service_UploadFile",
        "consumes": [
          "multipart/form-data"
        ],
        "responses": {
          "200": {
            "description": "A successful response.",
            "schema": {
              "$ref": "#/definitions/v1UploadFileResponse"
            }
          },
          "default": {
            "description": "An unexpected error response.",
            "schema": {
              "$ref": "#/definitions/rpcStatus"
            }
          }
        },
        "parameters": [
          {
            "name": "file",
            "description": "The file being to be uploaded.",
            "in": "formData",
            "required": true,
            "type": "file"
          }
        ],
        "tags": [
          "Service"
        ]
      }
    }
  },
  "definitions": {
    "v1UploadFileResponse": {
      "type": "object",
      "properties": {
        "file": {
          "$ref": "#/definitions/apiSomeOtherProtobuf"
        }
      }
    }
  }
}

For merging the json, I just tossed together a simple python script

#!/usr/bin/env python3

import argparse
import json
import mergedeep


def main():
    parser = argparse.ArgumentParser(description='Merges two json files')
    parser.add_argument('-b', '--base', required=True, help="the base json file")
    parser.add_argument('-p', '--patch', required=True, help="the patch json file")
    parser.add_argument('-o', '--out', required=True, help="the file to write the output to")
    args = parser.parse_args()

    with open(args.base) as f:
        base = json.load(f)

    with open(args.patch) as f:
        patch = json.load(f)

    mergedeep.merge(base, patch)

    with open(args.out, 'w') as f:
        json.dump(base, f, indent=2)


if __name__ == '__main__':
    main()