integration-tests: switch to go for backends to support TLS scenarios (#707)

* integration-tests: switch to go for backends to support TLS scenarios

* fix apply order

* fix duplicate port value

integration/backends/httpdetails/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+)
+
+func main() {
+	var (
+		certFile, keyFile, bindAddr string
+	)
+
+	flag.StringVar(&certFile, "cert-file", "", "the tls cert file to use")
+	flag.StringVar(&keyFile, "key-file", "", "the tls key file to use")
+	flag.StringVar(&bindAddr, "bind-addr", "", "the address to listen on")
+	flag.Parse()
+
+	var err error
+	if certFile != "" && keyFile != "" {
+		if bindAddr == "" {
+			bindAddr = ":5443"
+		}
+		fmt.Println("starting server on", bindAddr)
+		err = http.ListenAndServeTLS(bindAddr, certFile, keyFile, http.HandlerFunc(handle))
+	} else {
+		if bindAddr == "" {
+			bindAddr = ":5080"
+		}
+		fmt.Println("starting server on", bindAddr)
+		err = http.ListenAndServe(bindAddr, http.HandlerFunc(handle))
+	}
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to listen and serve: %v", err)
+		os.Exit(1)
+	}
+}
+
+type Result struct {
+	Headers    map[string]string `json:"headers"`
+	Method     string            `json:"method"`
+	Host       string            `json:"host"`
+	Port       string            `json:"port"`
+	Path       string            `json:"path"`
+	Query      string            `json:"query"`
+	RequestURI string            `json:"requestURI"`
+}
+
+func handle(w http.ResponseWriter, r *http.Request) {
+	res := &Result{
+		Headers:    map[string]string{},
+		Method:     r.Method,
+		Host:       r.Host,
+		Port:       r.URL.Port(),
+		Path:       r.URL.Path,
+		Query:      r.URL.RawQuery,
+		RequestURI: r.RequestURI,
+	}
+	for k := range r.Header {
+		res.Headers[k] = r.Header.Get(k)
+	}
+	res.Headers["Host"] = r.Host
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(200)
+	_ = json.NewEncoder(w).Encode(res)
+}