move HTTP middleware

Modify logging, based on github.com/gorilla/handlers.

Author: dmke

Diff for: service/middleware/clean_multipart.go

@@ -0,0 +1,20 @@
+package middleware
+
+import (
+	"log"
+	"net/http"
+)
+
+func CleanMultipart(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+
+		if r.MultipartForm == nil {
+			return
+		}
+		if err := r.MultipartForm.RemoveAll(); err != nil {
+			id, _ := GetRequestID(r)
+			log.Printf("%s: failed to cleanup multipart/form-data residues: %v", id, err)
+		}
+	})
+}

Diff for: service/middleware/logging.go

@@ -0,0 +1,82 @@
+package middleware
+
+import (
+	"bytes"
+	"net"
+	"net/http"
+	"os"
+	"strconv"
+)
+
+type responseLogger struct {
+	status, n int
+	http.ResponseWriter
+}
+
+func (l *responseLogger) Write(b []byte) (n int, err error) {
+	n, err = l.ResponseWriter.Write(b)
+	l.n += n
+	return
+}
+
+func (l *responseLogger) WriteHeader(status int) {
+	l.ResponseWriter.WriteHeader(status)
+	l.status = status
+}
+
+// Logging performs request logging. This method takes heavy inspiration
+// from (github.com/gorilla/handlers).CombinedLoggingHandler.
+func Logging(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		rl := &responseLogger{ResponseWriter: w}
+		url := *r.URL
+
+		next.ServeHTTP(rl, r)
+
+		username := "-"
+		if url.User != nil {
+			if name := url.User.Username(); name != "" {
+				username = name
+			}
+		}
+
+		host, _, err := net.SplitHostPort(r.RemoteAddr)
+		if err != nil {
+			host = r.RemoteAddr
+		}
+
+		uri := r.RequestURI
+
+		// Requests using the CONNECT method over HTTP/2.0 must use
+		// the authority field (aka r.Host) to identify the target.
+		// Refer: https://httpwg.github.io/specs/rfc7540.html#CONNECT
+		if r.ProtoMajor == 2 && r.Method == "CONNECT" {
+			uri = r.Host
+		}
+		if uri == "" {
+			uri = url.RequestURI()
+		}
+
+		id, haveID := GetRequestID(r)
+
+		var buf bytes.Buffer
+		buf.Grow(len(id) + len(r.Method) + len(host) + len(username) + len(uri) + 50) // reduce allocs
+		if haveID {
+			buf.WriteString(id)
+			buf.WriteString(": ")
+		}
+		buf.WriteString(host)
+		buf.WriteString(" - ")
+		buf.WriteString(username)
+		buf.WriteString(" - ")
+		buf.WriteString(r.Method)
+		buf.WriteByte(' ')
+		buf.WriteString(uri)
+		buf.WriteString(" - ")
+		buf.WriteString(strconv.Itoa(rl.status))
+		buf.WriteByte(' ')
+		buf.WriteString(strconv.Itoa(rl.n))
+		buf.WriteByte('\n')
+		_, _ = buf.WriteTo(os.Stderr)
+	})
+}

Diff for: requestid/requestid.go renamed to service/middleware/requestid.go

@@ -1,4 +1,4 @@
-package requestid
+package middleware
 
 import (
 	"context"
@@ -13,7 +13,7 @@ type contextKey string
 
 const ContextKey = contextKey("request-id")
 
-func Middleware(next http.Handler) http.Handler {
+func RequestID(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		id := uuid.Must(uuid.NewRandom()).String()
 		r = r.WithContext(context.WithValue(r.Context(), ContextKey, id))
@@ -22,3 +22,8 @@ func Middleware(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+func GetRequestID(r *http.Request) (string, bool) {
+	id, ok := r.Context().Value(ContextKey).(string)
+	return id, ok
+}

Diff for: requestid/requestid_test.go renamed to service/middleware/requestid_test.go

@@ -1,4 +1,4 @@
-package requestid
+package middleware
 
 import (
 	"net/http"
@@ -26,7 +26,7 @@ func TestMiddleware(t *testing.T) {
 	}
 
 	w := httptest.NewRecorder()
-	Middleware(http.HandlerFunc(captureContextID)).ServeHTTP(w,
+	RequestID(http.HandlerFunc(captureContextID)).ServeHTTP(w,
 		httptest.NewRequest(http.MethodGet, "/", nil))
 	assert.Equal(t, http.StatusOK, w.Code)
 

Diff for: service/service.go

@@ -6,11 +6,10 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	"os"
 	"time"
 
 	"github.com/digineo/texd/exec"
-	"github.com/digineo/texd/requestid"
+	"github.com/digineo/texd/service/middleware"
 	"github.com/digineo/texd/tex"
 	"github.com/gorilla/handlers"
 	"github.com/gorilla/mux"
@@ -62,12 +61,14 @@ func Start(opts Options) func(context.Context) error {
 	r.HandleFunc("/metrics", svc.HandleMetrics).Methods(http.MethodGet)
 
 	// r.Use(handlers.RecoveryHandler())
-	r.Use(requestid.Middleware)
+	r.Use(middleware.RequestID)
 	r.Use(handlers.CompressHandler)
+	r.Use(middleware.Logging)
+	r.Use(middleware.CleanMultipart)
 
 	srv := http.Server{
 		Addr:    opts.Addr,
-		Handler: handlers.CombinedLoggingHandler(os.Stdout, r),
+		Handler: r,
 	}
 
 	go func() {