Summary 

In this chapter, we first introduced the HTTP router. We tried to create HTTP routes using Go's net/http package. Then, we briefly discussed ServeMux with an example. We saw how to add multiple handler functions to multiple routes. Then, we introduced a lightweight router package called httprouter, which allows developers to create elegant routes, with the option of parsing parameters passed in the URL path.

We can also serve files over the HTTP using httprouter. We built a small service to get the Go version and file contents (read-only). That example can be extended to fetch any system information or run a system command.

Next, we introduced the popular Go routing library, gorilla/mux. We discussed how it is different from httprouter and explored its functionality by implementing two examples. We explained how Vars can be used to get path parameters and r.URL.Query to parse query parameters.

As part of securing API routes, we discussed SQL injection and how it can happen in our applications. We have also seen the counter measures. By the end of this chapter, one can define routes and handler functions to accept HTTP API requests.

In the next chapter, we will look at Middleware functions, which act as tamperers for HTTP requests and responses. That phenomenon helps us to modify the API response on the fly. The next chapter also features Remote Procedure Call (RPC).