Refacter API server emphasis on logging

* To aid in debugging log API request and response bodies at trace
  level. Events can be correlated using the X-Reference-Id.
* Server now echos X-Reference-Id from client if set, otherwise
  generates an unique id.
* Move logic for X-Reference-Id into middleware
* Change uses of Header.Add() to Set() when setting Content-Type
* Log API operations in Apache format using gorilla middleware
* Port server code to use BaseContext and ConnContext

Fixes #10053

Signed-off-by: Jhon Honce <jhonce@redhat.com>

pkg/api/server/handler_logging.go

@@ -0,0 +1,51 @@
+package server
+
+import (
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/sirupsen/logrus"
+)
+
+type responseWriter struct {
+	http.ResponseWriter
+}
+
+var apiLogger = &logrus.Logger{
+	Formatter: &logrus.TextFormatter{
+		DisableColors:          true,
+		DisableLevelTruncation: true,
+		FullTimestamp:          true,
+		QuoteEmptyFields:       true,
+		TimestampFormat:        time.RFC3339,
+	},
+	Level: logrus.TraceLevel,
+	Out:   logrus.StandardLogger().Out,
+}
+
+func (l responseWriter) Write(b []byte) (int, error) {
+	apiLogger.WithFields(logrus.Fields{
+		"API":            "response",
+		"X-Reference-Id": l.Header().Get("X-Reference-Id"),
+	}).Trace(string(b))
+	return l.ResponseWriter.Write(b)
+}
+
+func loggingHandler() mux.MiddlewareFunc {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			annotated := apiLogger.WithFields(logrus.Fields{
+				"API":            "request",
+				"X-Reference-Id": r.Header.Get("X-Reference-Id"),
+			})
+			r.Body = ioutil.NopCloser(
+				io.TeeReader(r.Body, annotated.WriterLevel(logrus.TraceLevel)))
+
+			w = responseWriter{ResponseWriter: w}
+			h.ServeHTTP(w, r)
+		})
+	}
+}