Proto to OpenAPIv3 - How to annotate Query Parameters as "required"?

[aazizpc]

Hi, I have a gRPC implementation of REST services. It's divided across two proto files - one for the operations and one for the request and response messages.

One of them, a GET Service, accepts a single query parameter as input, which I want to annotate as "required" so that I can use the openApiv3 converter and get that information into the OpenAPI yaml spec.

I tried to do it in the following two ways:

1. Adding it to the message, and not the operation, just like how we do with the JSON payload values.

Proto Annotation:

message GetEngagementsRequest {
  option (openapi.v3.schema) = {
    title: "Engagements Request";
    required: "crn";
  };
  string crn = 1 [
    (openapi.v3.property) = {
      example: {
        yaml: "crn123",
      }
      title: "Customer reference number";
      min_length: 1;
    }
  ];
}

There's no mention of "required" in the yaml file output: OpenAPI YAML file:

    /engagements/get-engagements/v1:
        get:
            tags:
                - Entitlement
            operationId: Entitlement_GetEngagements
            parameters:
                - name: crn
                  in: query
                  schema:
                    type: string

2. Tried to set the parameter as required in the operation level using the annotations below.

Proto Annotation:

rpc GetEngagements(model.GetEngagementRequest) returns (model.GetEngagementResponse) {
    option (google.api.http) = {
      get: "/engagement/get-engagements/v1"
    };
    option (openapi.v3.operation) = {
      description: "Get engagements";
      parameters: [
        {
          parameter:
          {
            name: "crn";
            required: true;
            in: "query";
            example: {
              yaml: "crn123",
            }
            description: "Customer reference number";
            schema: {
              schema:
              {
                  type: "string"
              }
            }
          }
        }
      ]
    };
  }

This seems to work, but brings a duplicate one from the request message. OpenAPI YAML:

    /engagements/get-engagements/v1:
        get:
            tags:
                - Entitlement
            description: Get Engagements
            operationId: Entitlement_GetEngagements
            parameters:
                - name: crn
                  in: query
                  schema:
                    type: string
                - name: crn
                  in: query
                  description: Customer reference number
                  required: true
                  schema:
                    type: string
                  example: crn123

[2minchul]

It seems like this has been an issue for a while, but I still haven't found a solution. I think this problem is related to the following:

• https://github.com/google/gnostic/issues/379
• https://github.com/google/gnostic/pull/403
• https://github.com/google/gnostic/pull/404
• https://github.com/google/gnostic/pull/405

If anyone knows a solution, please help.