command/agent: added missing syslog wrapper

command/agent/syslog.go

@@ -0,0 +1,49 @@
+package agent
+
+import (
+	"bytes"
+	"github.com/hashicorp/go-syslog"
+)
+
+// levelPriority is used to map a log level to a
+// syslog priority level
+var levelPriority = map[string]gsyslog.Priority{
+	"TRACE": gsyslog.LOG_DEBUG,
+	"DEBUG": gsyslog.LOG_INFO,
+	"INFO":  gsyslog.LOG_NOTICE,
+	"WARN":  gsyslog.LOG_WARNING,
+	"ERR":   gsyslog.LOG_ERR,
+	"CRIT":  gsyslog.LOG_CRIT,
+}
+
+// SyslogWrapper is used to cleaup log messages before
+// writing them to a Syslogger. Implements the io.Writer
+// interface.
+type SyslogWrapper struct {
+	l gsyslog.Syslogger
+}
+
+// Write is used to implement io.Writer
+func (s *SyslogWrapper) Write(p []byte) (int, error) {
+	// Extract log level
+	var level string
+	afterLevel := p
+	x := bytes.IndexByte(p, '[')
+	if x >= 0 {
+		y := bytes.IndexByte(p[x:], ']')
+		if y >= 0 {
+			level = string(p[x+1 : x+y])
+			afterLevel = p[x+y+2:]
+		}
+	}
+
+	// Each log level will be handled by a specific syslog priority
+	priority, ok := levelPriority[level]
+	if !ok {
+		priority = gsyslog.LOG_NOTICE
+	}
+
+	// Attempt the write
+	err := s.l.WriteLevel(priority, afterLevel)
+	return len(p), err
+}