package middlewares import ( "log" "net/http" "os" "github.com/gorilla/handlers" ) // Logger is a middleware handler that logs the request as it goes in and the response as it goes out. type Logger struct { file *os.File } // NewLogger returns a new Logger instance. func NewLogger(file string) *Logger { if len(file) > 0 { fi, err := os.OpenFile(file, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666) if err != nil { log.Fatal("Error opening file", err) } return &Logger{fi} } return &Logger{nil} } func (l *Logger) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) { if l.file == nil { next(rw, r) } else { handlers.CombinedLoggingHandler(l.file, next).ServeHTTP(rw, r) } } // Close closes the logger (i.e. the file). func (l *Logger) Close() { if l.file != nil { l.file.Close() } }