Defining custom go struct tags for protobuf message fields

Question

I am new to grpc and have been trying to just fetch a json response from a webserver. The stub can then request the json from the rpc server.

In my .proto file, I created a message type:

message Post {
    int64 number = 1;
    string now = 2;
    string name = 3;
}

But I am not able to marshal the number field, since protoc produces the struct pb.go file with a number tag:

{
        "no": "23",
        "now": "12:06:46",
        "name": "bob"
}

How can I force the Message to be 'converted' with a tag other than the lowercase name of the message field? Such as using the json tag no, even if the field name in the Message is number.

Answer 1

You can set a proto3 field option on the proto message definition with a json_name

message Post {
    int64 number = 1 [json_name="no"];
    string now = 2;
    string name = 3;
}

link to the docs