feat: add rate limiter proxy

rate/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"strconv"
+)
+
+func main() {
+	// read config file and parse it
+	confB, err := os.ReadFile("proxy-config.json")
+	if err != nil {
+		log.Fatalf("reading config.json: %v", err)
+	}
+
+	hn := &Handler{}
+	err = json.Unmarshal(confB, hn)
+	if err != nil {
+		log.Fatalf("unmarshaling config.json: %v", err)
+	}
+
+	proxyURL, err := url.Parse(hn.ProxyTarget)
+	if err != nil {
+		log.Fatalf("parsing proxy_target as URL: %v", err)
+	}
+	hn.proxy = &httputil.ReverseProxy{
+		Rewrite: func(pr *httputil.ProxyRequest) {
+			pr.SetURL(proxyURL)
+			pr.Out.Host = pr.In.Host
+		},
+	}
+	hn.limiter = NewLimiter()
+	hn.client = &http.Client{}
+
+	log.Printf("serving on port %v", hn.Port)
+
+	err = http.ListenAndServe(":"+strconv.Itoa(hn.Port), hn)
+	if err != nil {
+		log.Fatalf("listening on port %v: %v", hn.Port, err)
+	}
+
+}