This gist creates 2 files -- http_connection_reuse_test_server.go will bring up a server and http_connection_reuse_test_client.go will bring a client that make calls to that server. This is to test the TCP connection reuse for new HTTP connections

http_connection_reuse_test_client.go

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
)

func main() {

	for i := 0; i < 10; i++ {
		client := http.Client{}
		// I am running a server here that can be found here https://gist.github.com/rachitchauhan43/8b7fc6a24074d0d0c0d9095f4e583a07#file-http_connection_reuse_test_server-go
		req, err := http.NewRequest("GET", "http://localhost:8090/hello", nil)
		req.Header = http.Header{
			"Host":          {"www.host.com"},
			"Content-Type":  {"application/json"},
			"Authorization": {"Bearer Token"},
		}

		resp, err := client.Do(req)
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()
		//Commenting out bellow line will lead to multiple TCP connections being in TIME_WAIT state
		_, err = ioutil.ReadAll(resp.Body)

		fmt.Println("Response status:", resp.Status)
	}

}

http_connection_reuse_test_server.go

package main

import (
	"fmt"
	"net/http"
)

func hello(w http.ResponseWriter, req *http.Request) {

	fmt.Fprintf(w, "helloyellow\n")
}

func headers(w http.ResponseWriter, req *http.Request) {

	for name, headers := range req.Header {
		for _, h := range headers {
			fmt.Fprintf(w, "%v: %v\n", name, h)
		}
	}
}

func main() {
	// This is a simple test server exposing 2 endpoint at port 8090 --> /hello and /headers
	http.HandleFunc("/hello", hello)
	http.HandleFunc("/headers", headers)

	http.ListenAndServe(":8090", nil)
}