initial commit

routes/logging.go

@@ -0,0 +1,97 @@
+package routes
+
+import (
+	"errors"
+	"fmt"
+	"foobar/metrics"
+	"log"
+	"net/http"
+	"runtime/debug"
+	"time"
+)
+
+type wrappedWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func (w *wrappedWriter) WriteHeader(statusCode int) {
+	w.ResponseWriter.WriteHeader(statusCode)
+	w.statusCode = statusCode
+}
+
+func logging(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+
+		wrapped := &wrappedWriter{
+			ResponseWriter: w,
+			statusCode:     http.StatusOK,
+		}
+
+		var panicked bool
+		err := recoverServeHTTP(next, wrapped, r)
+		if err != nil {
+			wrapped.Write([]byte("500 error"))
+			log.Println(err)
+			panicked = true
+		}
+
+		var (
+			latency    = time.Since(start)
+			path       = r.URL.Path
+			statusCode = wrapped.statusCode
+		)
+		if path == "/metrics" && statusCode == 200 {
+			return
+		}
+		log.Printf("%v %v %v %v", wrapped.statusCode, r.Method, r.URL.Path, latency)
+
+		metrics.ResponseLatencyObserve(latency, statusCode, panicked, r)
+	})
+}
+
+func recoverServeHTTP(next http.Handler, w http.ResponseWriter, r *http.Request) (e error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			var err error
+			switch v := rec.(type) {
+			case error:
+				err = v
+			default:
+				err = fmt.Errorf("%v", v)
+			}
+			stack := debug.Stack()
+			w.WriteHeader(http.StatusInternalServerError)
+			e = errors.Join(err, fmt.Errorf(string(stack)))
+		}
+	}()
+	next.ServeHTTP(w, r)
+	return
+}
+
+func logError(err error) {
+	if err == nil {
+		log.Printf("LOG: Erro Nulo!?\n")
+	} else {
+		log.Printf("LOG: %s\n", err.Error())
+	}
+	log.Println(string(debug.Stack()))
+}
+
+func logInternalError(w http.ResponseWriter, err error) {
+	logError(err)
+	http.Error(w, `500`, http.StatusInternalServerError)
+}
+
+func httpErrorf(w http.ResponseWriter, status int, formatString string, format ...interface{}) {
+	http.Error(w, fmt.Sprintf(formatString, format...), status)
+}
+
+func formValueMissing(field string, r *http.Request) error {
+	return fmt.Errorf(
+		"campo '%s' em formulário não pôde ser encontrado. Content-Type: %s",
+		field,
+		r.Header.Get("Content-Type"),
+	)
+}