Moved logging middleware into its own package

middleware/log/log.go

@@ -0,0 +1,70 @@
+package log
+
+import (
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/mholt/caddy/middleware"
+)
+
+// New instantiates a new instance of logging middleware.
+func New(c middleware.Controller) (middleware.Middleware, error) {
+	var logWhat, outputFile, format string
+	var logger *log.Logger
+
+	for c.Next() {
+		c.Args(&logWhat, &outputFile, &format)
+
+		if logWhat == "" {
+			return nil, c.ArgErr()
+		}
+		if outputFile == "" {
+			outputFile = defaultLogFilename
+		}
+		switch format {
+		case "":
+			format = defaultReqLogFormat
+		case "{common}":
+			format = commonLogFormat
+		case "{combined}":
+			format = combinedLogFormat
+		}
+	}
+
+	// Open the log file for writing when the server starts
+	c.Startup(func() error {
+		var err error
+		var file *os.File
+
+		if outputFile == "stdout" {
+			file = os.Stdout
+		} else if outputFile == "stderr" {
+			file = os.Stderr
+		} else {
+			file, err = os.OpenFile(outputFile, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+			if err != nil {
+				return err
+			}
+		}
+
+		logger = log.New(file, "", 0)
+		return nil
+	})
+
+	return func(next http.HandlerFunc) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			sw := middleware.NewResponseRecorder(w)
+			next(sw, r)
+			rep := middleware.NewReplacer(r, sw)
+			logger.Println(rep.Replace(format))
+		}
+	}, nil
+}
+
+const (
+	defaultLogFilename  = "access.log"
+	commonLogFormat     = `{remote} ` + middleware.EmptyStringReplacer + ` [{when}] "{method} {uri} {proto}" {status} {size}`
+	combinedLogFormat   = commonLogFormat + ` "{>Referer}" "{>User-Agent}"`
+	defaultReqLogFormat = commonLogFormat
+)