Add Metrics

pkg/middlewares/metrics/recorder.go

@@ -0,0 +1,37 @@
+package metrics
+
+import (
+	"bufio"
+	"net"
+	"net/http"
+)
+
+// responseRecorder captures information from the response and preserves it for
+// later analysis.
+type responseRecorder struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+// WriteHeader captures the status code for later retrieval.
+func (r *responseRecorder) WriteHeader(status int) {
+	r.ResponseWriter.WriteHeader(status)
+	r.statusCode = status
+}
+
+// Hijack hijacks the connection
+func (r *responseRecorder) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return r.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+// CloseNotify returns a channel that receives at most a
+// single value (true) when the client connection has gone
+// away.
+func (r *responseRecorder) CloseNotify() <-chan bool {
+	return r.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+// Flush sends any buffered data to the client.
+func (r *responseRecorder) Flush() {
+	r.ResponseWriter.(http.Flusher).Flush()
+}