Go Practice

I set up this repository to screw around with Go and gRPC a little bit. Got around to leveraging gRPC and Protobuf to build a super simple application which provides the client with show recommendations. I wrote some fairly detailed comments throughout just in case anybody wants to look this over, but I will briefly describe the setup below.

Protobuf

With protobuf, we can define the structure of our incoming and outgoing messages, along with services which will provide specific pieces of functionality. If you look at proto/application.proto you will see that we define our input (ShowRecommendationRequest), output (ShowRecommendation) and our service (ShowRecommendationService). We will use Protobuf to generate Go code from this file so that we can instantiate these messages and services, and handle them with gRPC. The Protobuf-generated code can be found under src/application/application.pb.go.

gRPC

gRPC allows us to pass Protobuf messages back and forth, negating the use of JSON. In our server.go file, you can see that we use the gRPC Go library to serve up our ShowRecommendationService, which will handle the input that our client provides.

Running the Example

When running our example, the expectation is that we can pass our Protobuf-generated messages back and forth between the client and server. We will send the server a ShowRecommendationRequest with our name, and expect to receive a ShowRecommendation which includes our name and the name of the show that is being recommended.

Let's run our server like so:

$ go run server.go 
Server running...

Now, let's execute our client code a few times and observe the results:

$ go run client.go 
2022/03/03 13:15:34 Response from server: name:"Matty" show:"Daredevil"
$ go run client.go 
2022/03/03 13:15:36 Response from server: name:"Matty" show:"Midnight Mass"
$ go run client.go 
2022/03/03 13:15:39 Response from server: name:"Matty" show:"The Haunting of Hill House"

If you were to change the name that we provide in our ShowRecommendationRequest message, you would see that change reflected in the resulting ShowRecommendation as well.

Further Considerations

A couple of things worth noting that I will list out below.

1. At the time of setting up this project, I am brand new to writing Go. I am by no means recommending anything in here as standard practice; I am just familiarizing myself with these tools.
2. The Protobuf-generated code encompasses the server and client functionality. In this example our client lives in the same codebase as our server, but if we had a client that lived in a separate codebase (very likely if implementing microservices), we would need to share that generated code somehow. This could possibly be achieved by storing all Protobuf definitions and generated code in a separate repository, which is then programmatically copied into other projects with Terraform. It could also possibly be achieved by storing these results in a shared library like a Rubygem which could then be versioned and required by multiple projects. A coworker also recommended Git sub-modules as a potential solution.
3. This example is only intended to run on a local machine, so of course there is no proper routing and SSL is not supported. As a result, the setup of our gRPC server is exceedingly simple. It is safe to assume that doing something like this in a production environment would require some extra work and configuration.