Allow repeated field in gRPC Transcoding

Question

I'm using gRPC in Google CLoud Endpoints I'm using quick example for endpoint python
I addition one function for SayHelloRepeated but don't know how to transcode repeated field.

helloworld.proto

service Greeter {
...

rpc SayHelloRepeated (RepeatedHello) returns (HelloReply) {}

...
}

message RepeatedHello {
repeated HelloRequest hello_request = 1;
}

message HelloRequest {
string name = 1;
}

api_config_http.yaml

http:
rules:
    ...

    - selector: helloworld.Greeter.SayHelloRepeated
    get: /v1/rsayhello/{hello_request}

    ...

When I try to deploy api_config_http.yaml it give me error Repeated field not allowed

ERROR: (gcloud.endpoints.services.deploy) INVALID_ARGUMENT: Cannot convert to service config.

kind: ERROR message: "http: repeated field not allowed: reached via \'hello_request\' on message \'helloworld.RepeatedHello\'."

Update

What If HelloRequest has multiple fields not just the one name field then what to do.

message HelloRequest {
string name = 1;
string message = 2;
}

user_12767257 · Answer

As per the official documentation Package google.api:

Each mapping specifies a URL path template and an HTTP method. The path template may refer to one or more fields in the gRPC request message, as long as each field is a non-repeated field with a primitive (non-message) type.

This means that you can't use a repeated field in the gRPC. So, you can't use this exact format for you to use repeated fields.

I would recommend you to check this part of the documentation - gRPC Transcoding - to get more information on how to perform a workaround to achieve the use of repeated fields.

Let me know if the information helped you!

Allow repeated field in gRPC Transcoding

1 Answers