How to translate a flask route with path parameters to gRPC service?-CodePudding

I'm a little confused on how a simple flask route can translate to a gRPC service reading the official gRPC introduction.

Suppose I have a flask route like

@app.route("/hello/<string:name>/")
def hello_name():
    return "PLACEHOLDER"

If I wanted to define that as a Service in gRPC how would that look? It does not take any request data but instead asks for the data directly in the path. Would it be defined directly as /hello/<string:name/? I couldn't seem to find docs on that.

CodePudding user response：

In Flask, these are called route params.

In gRPC transcoding (!) see below, you'll need to identify the variable name in the definition:

message HelloRequest {
    string name = 1;
}

rpc Hello(HelloRequest) returns (HelloResponse) {
    option (google.api.http) = {
        get: "/hello/{name}"
    };
}

In order to make an HTTP/1 e.g. GET request to an HTTP/2 gRPC service, you'll need to use gRPC HTTP Transcoding. This places a proxy between your e.g. Flask client and the gRPC service and converts the client's HTTP/1 e.g. GETs into HTTP/2 gRPC calls. It's non-trivial but it works.

See: