How to modularize handler functions and routes

Question

I realized that when building a web server, all of the routes and functions that handle them are in the main.go file. As the application grows, I imagine it could be hard to keep track of everything.

Is there a convention regarding "storing" the routes and handler functions in a file other than main.go?

You can have any number of files in your main package. I suggest you start with the documentation and see how packages work, which will probably provide a lot of insight into how you can modularize your code. — JimB, Oct 30 '19 at 23:21

score 1 · Accepted Answer · answered Oct 30 '19 at 22:42

Here is how I do it. Say you have a ping handler which checks a database connection, and you have it in a package named your/app/animal:

package animal

...

func Ping(db *sql.DB) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        if err := db.PingContext(context.TODO()); err != nil {
            http.Error(w, err, http.StatusInternalServerError)
        }
    })
}

You can set it up like:

package main

...

func main() {
   db, _ := sql.Open("foo",os.GetEnv("DB"))
   http.Handle("/ping",animal.Ping(db))
   log.Fatal(http.ListenAndServe(os.GetEnv("BIND"),nil)
}

How to modularize handler functions and routes

1 Answers1