1 files changed, 54 insertions, 0 deletions
diff --git a/icanhazallips.go b/icanhazallips.go
new file mode 100644
index 0000000..bcca91e
--- /dev/null
+++ b/icanhazallips.go
@@ -0,0 +1,54 @@
+// https://gist.github.com/miguelmota/7b765edff00dc676215d6174f3f30216
+package main
+
+import (
+	"errors"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+)
+
+func getIP(r *http.Request) (string, error) {
+	ips := r.Header.Get("X-Forwarded-For")
+	splitIps := strings.Split(ips, ",")
+
+	if len(splitIps) > 0 {
+		netIP := net.ParseIP(splitIps[len(splitIps)-1])
+		if netIP != nil {
+			return netIP.String(), nil
+		}
+	}
+
+	ip, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		return "", err
+	}
+
+	netIP := net.ParseIP(ip)
+	if netIP != nil {
+		ip := netIP.String()
+		if ip == "::1" {
+			return "127.0.0.1", nil
+		}
+		return ip, nil
+	}
+
+	return "", errors.New("IP not found")
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	ip, err := getIP(r)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(ip))
+}
+
+func main() {
+	http.HandleFunc("/", handler)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}