first version

module/tools/tools.go

@@ -0,0 +1,30 @@
+package tools
+
+import (
+	"net"
+	"net/http"
+	"net/textproto"
+	"strings"
+)
+
+// RemoteIP -
+func RemoteIP(req *http.Request) string {
+	ips := make([]string, 0)
+	if headerAddr := req.Header.Get(textproto.CanonicalMIMEHeaderKey("X-Forwarded-For")); len(headerAddr) > 0 {
+		ips = strings.Split(headerAddr, ",")
+	}
+	if len(ips) > 0 && len(ips[0]) > 0 {
+		rip, _, err := net.SplitHostPort(ips[0])
+		if err != nil {
+			return ips[0]
+		}
+		return rip
+	}
+
+	ip := req.RemoteAddr
+	if rip, _, err := net.SplitHostPort(ip); err == nil {
+		return rip
+	} else {
+		return ip
+	}
+}