Summary

In this chapter, we gave an introduction to the REST API. We saw that REST is not a protocol, but an architectural pattern. HTTP is the actual protocol on which we can implement our REST service. We jumped into the fundamentals of the REST API to be clear about what they actually are. Then we explored types of web services. Before REST, we had something called SOAP, which used XML as its data format. REST operates on JSON as its primary format. REST has verbs and status codes. We saw what these status codes refer to.

We designed and implemented a simple service that finds the fastest mirror site to download OS images from all Debian mirror sites hosted worldwide. In this process, we also saw how to package a Go project into a binary. We understood the GOPATH environment variable, which is a workspace definition in Go. We now know that all packages and projects reside on that path.

Next, we jumped into the world of OpenAPI specification by introducing Swagger UI and Swagger files. The structure of these files and how to run Swagger UI with the help of Docker were discussed briefly. We also saw why a developer should start API development by writing down the specifications in the form of a Swagger file.

In the next chapter, we will dig deeper into URL routing. Starting from the built-in router, we will explore Gorilla Mux, a powerful URL routing library.