Added middleware to set IP address to request context + helpers

context.go

@@ -0,0 +1,26 @@
+package clientip
+
+import "context"
+
+// contextKey is a type used for keys in the context.
+// These keys are used to store and retrieve values from the context.
+// The keys are unique and are used to avoid conflicts with other keys.
+type contextKey struct{ name string }
+
+// requestIPKey is the key used to store the client's IP address in the request context.
+var requestIPKey = contextKey{"request_ip"}
+
+// SetIPAddress sets the client's IP address in the request context.
+// This IP address can be used in the next handler.
+func SetIPAddress(ctx context.Context, ip string) context.Context {
+	return context.WithValue(ctx, requestIPKey, ip)
+}
+
+// GetIPAddress gets the client's IP address from the request context.
+// If the IP address is not found in the context, it returns an empty string.
+func GetIPAddress(ctx context.Context) string {
+	if ip, ok := ctx.Value(requestIPKey).(string); ok {
+		return ip
+	}
+	return ""
+}

middleware.go

@@ -23,3 +23,17 @@ func Middleware(headers ...string) func(http.Handler) http.Handler {
 		return http.HandlerFunc(fn)
 	}
 }
+
+// IpToContext is a middleware that sets the client's IP address in the request context.
+// This IP address can be used in the next handler.
+func IpToContext(ctxKey any) func(http.Handler) http.Handler {
+	return func(h http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			// Get user ip address and set it to the request context
+			// This ip address can be used in the next handler
+			h.ServeHTTP(w, r.WithContext(SetIPAddress(r.Context(), r.RemoteAddr)))
+		}
+
+		return http.HandlerFunc(fn)
+	}
+}