go-grpc VS grpcurl

Introduction to gRPC

For this article also we will be using the Online Bookshop example and leveraging the same Protobufs as we saw before. For those who aren’t familiar with or missed this series, you can find them from here.

💡 As always, all the code samples documentation can be found at: https://github.com/sahansera/go-grpc

grpcurl

The API server will be built and start running on port 50051. You can test the functionality using a gRPC client of your choice like grpcurl or Postman.

> What is the ubiquitous utility for interacting with gRPC? We have curl for REST. What is openAPI of gRPC?

grpcurl[1] combined with gRPC server reflection[2]. The schema is compiled into the server as an encoded proto which is exposed via server reflection, which grpcurl reads to send correctly encoded requests.

[1] https://github.com/fullstorydev/grpcurl

The whole idea behind the post is that accessing the gRPC service with regular tools is impossible. To test, we need a dedicated tool nonetheless. I found grpcurl. Let's install it and use it to list available services:

gRpcurl is a cool little tool to look at btw. Had to use it at my job before. Can call a gRPC via a curl like command. Regular curl doesn't support HTTP2. Had to use TLS with some tokens even. But you can reference a local .proto(gRPC protobuf file for the call) and make things easier for yourself if you hate reading instructions on command line args like I do.

A simple GRPC client built using grpcurl.

Try testing with grpcurl, using the -H or -rpc-header flags to set the appropriate header.