init

go.mod

@@ -0,0 +1,3 @@
+module gitea.hbanafa.com/hesham/myip
+
+go 1.21.1

main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"net/netip"
+)
+
+// @title My IP
+// @version 0.1
+// @description Get the requseters Real IP, based on HTTP Requests
+func main() {
+    handler := http.NewServeMux()
+    handler.HandleFunc("/", handleRoot)
+
+    log.Fatal(http.ListenAndServe(":8080", handler))
+}
+
+type ResponseType string
+
+const (
+    TEXT ResponseType = "TEXT"
+    JSON ResponseType = "JSON"
+    DEFAULT ResponseType = TEXT
+) 
+
+func (r *ResponseType) IsValid() bool {
+
+    // This is pretty ugly
+    // TODO: Comapre with ignore-case
+    if *r == TEXT {
+        return true
+    }
+
+    if *r == JSON {
+        return true
+    }
+
+    return false
+}
+
+func handleRoot(w http.ResponseWriter, r *http.Request) {
+
+    if r.Method != "GET" {
+        w.WriteHeader(http.StatusBadRequest)
+    }
+    var Type ResponseType
+    Type = ResponseType(r.URL.Query().Get("t"))
+    
+    if !Type.IsValid() {
+        // Using defualt    
+        Type = DEFAULT
+    }
+
+    log.Printf("Type: %v\n", Type)
+    ip := determineRealIP(r)
+
+    w.WriteHeader(http.StatusOK)
+    err := writeFormattedIP(w, Type, ip)
+    if err != nil {
+        log.Println(err.Error())
+        w.WriteHeader(http.StatusInternalServerError)
+    }
+}
+
+func determineRealIP(r *http.Request) string {
+    ip := r.RemoteAddr
+
+    xRealIP := r.Header.Get("X-Real-IP")
+    if xRealIP != "" {
+        ip = xRealIP
+    }
+
+    ipPort, err := netip.ParseAddrPort(ip)
+    if err != nil {
+        log.Println("Error while parsing AddrPort:", err.Error())
+    }
+
+    ipAddrPort := ipPort.Addr().String()
+    if ipAddrPort == "invalid IP" {
+        ipAddr, err := netip.ParseAddr(ip)
+        if err != nil {
+            // Last resort
+            log.Println("Error while parsing Addr:", err.Error())
+            return ip
+        }
+        ip = ipAddr.String()
+    }
+
+    return ip
+}
+
+func writeFormattedIP(w http.ResponseWriter, Type ResponseType, ip string)  error {
+    if Type == TEXT {
+        _, err := w.Write([]byte(ip))
+        if err != nil {
+            return err
+        }
+        return nil
+    }
+
+    if Type == JSON {
+        // TODO: Use MarshalIndent
+        jsonResponse, err := json.Marshal(map[string]string{"ip": ip})
+        if err != nil {
+            return err
+        }
+        _, err = w.Write(jsonResponse)
+        if err != nil {
+            return err
+        }
+    }
+
+    return nil
+}
+
+