Added logging

vendor/github.com/op/go-logging/syslog.go

@@ -0,0 +1,53 @@
+// Copyright 2013, Örjan Persson. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//+build !windows,!plan9
+
+package logging
+
+import "log/syslog"
+
+// SyslogBackend is a simple logger to syslog backend. It automatically maps
+// the internal log levels to appropriate syslog log levels.
+type SyslogBackend struct {
+	Writer *syslog.Writer
+}
+
+// NewSyslogBackend connects to the syslog daemon using UNIX sockets with the
+// given prefix. If prefix is not given, the prefix will be derived from the
+// launched command.
+func NewSyslogBackend(prefix string) (b *SyslogBackend, err error) {
+	var w *syslog.Writer
+	w, err = syslog.New(syslog.LOG_CRIT, prefix)
+	return &SyslogBackend{w}, err
+}
+
+// NewSyslogBackendPriority is the same as NewSyslogBackend, but with custom
+// syslog priority, like syslog.LOG_LOCAL3|syslog.LOG_DEBUG etc.
+func NewSyslogBackendPriority(prefix string, priority syslog.Priority) (b *SyslogBackend, err error) {
+	var w *syslog.Writer
+	w, err = syslog.New(priority, prefix)
+	return &SyslogBackend{w}, err
+}
+
+// Log implements the Backend interface.
+func (b *SyslogBackend) Log(level Level, calldepth int, rec *Record) error {
+	line := rec.Formatted(calldepth + 1)
+	switch level {
+	case CRITICAL:
+		return b.Writer.Crit(line)
+	case ERROR:
+		return b.Writer.Err(line)
+	case WARNING:
+		return b.Writer.Warning(line)
+	case NOTICE:
+		return b.Writer.Notice(line)
+	case INFO:
+		return b.Writer.Info(line)
+	case DEBUG:
+		return b.Writer.Debug(line)
+	default:
+	}
+	panic("unhandled log level")
+}