feat(logger): implement a logger middleware

pkg/logger/body_writer.go

@@ -0,0 +1,46 @@
+package logger
+
+import (
+	"bufio"
+	"errors"
+	"net"
+	"net/http"
+)
+
+type bodyWriter struct {
+	http.ResponseWriter
+	status int
+}
+
+func newBodyWriter(writer http.ResponseWriter) *bodyWriter {
+	return &bodyWriter{
+		ResponseWriter: writer,
+		status:         http.StatusNotImplemented,
+	}
+}
+
+// implements http.ResponseWriter
+func (w *bodyWriter) Write(b []byte) (int, error) {
+	return w.ResponseWriter.Write(b)
+}
+
+// implements http.ResponseWriter
+func (w *bodyWriter) WriteHeader(code int) {
+	w.status = code
+	w.ResponseWriter.WriteHeader(code)
+}
+
+// implements http.Flusher
+func (w *bodyWriter) Flush() {
+	if f, ok := w.ResponseWriter.(http.Flusher); ok {
+		f.Flush()
+	}
+}
+
+// implements http.Hijacker
+func (w *bodyWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	if hi, ok := w.ResponseWriter.(http.Hijacker); ok {
+		return hi.Hijack()
+	}
+	return nil, nil, errors.New("Hijack not supported")
+}