import Logger middleware

1 files changed, 65 insertions, 0 deletions

diff --git a/logger.go b/logger.go
new file mode 100644
index 0000000..d1a22ea
--- /dev/null
+++ b/logger.go
@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: 2020 Ethel Morgan
+//
+// SPDX-License-Identifier: MIT
+
+package httputil
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"go.eth.moe/logger"
+)
+
+type (
+	responseWriter struct {
+		http.ResponseWriter
+		StatusCode int
+	}
+)
+
+func (rw *responseWriter) WriteHeader(code int) {
+	rw.StatusCode = code
+	rw.ResponseWriter.WriteHeader(code)
+}
+
+// Logger is a middleware for logging HTTP requests and responses, using go.eth.moe/logger.
+func Logger(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		log, ctx := logger.FromContext(r.Context())
+
+		log.AddField("http.client", r.RemoteAddr)
+		if xForwardedFor := r.Header.Get("X-Forwarded-For"); xForwardedFor != "" {
+			log.AddField("http.client", xForwardedFor)
+		}
+		log.AddField("http.method", r.Method)
+		log.AddField("http.path", r.URL.Path)
+		log.AddField("http.useragent", r.UserAgent())
+
+		for k, v := range mux.Vars(r) {
+			log.AddField(fmt.Sprintf("http.vars.%s", k), v)
+		}
+		for k, vs := range r.URL.Query() {
+			if len(vs) == 1 {
+				log.AddField(fmt.Sprintf("http.query.%s", k), vs[0])
+				continue
+			}
+			log.AddField(fmt.Sprintf("http.query.%s", k), vs)
+		}
+		for k, vs := range r.Form {
+			if len(vs) == 1 {
+				log.AddField(fmt.Sprintf("http.form.%s", k), vs[0])
+				continue
+			}
+			log.AddField(fmt.Sprintf("http.form.%s", k), vs)
+		}
+
+		rw := responseWriter{ResponseWriter: w, StatusCode: 200}
+
+		next.ServeHTTP(&rw, r.WithContext(ctx))
+
+		log.AddField("http.status", rw.StatusCode)
+		log.Info("served HTTP request")
+	})
+}