diff --git a/README.md b/README.md index 50faff6..178123d 100644 --- a/README.md +++ b/README.md @@ -286,6 +286,11 @@ The built-in logging formatters are: field to `true`. To force no colored output even if there is a TTY set the `DisableColors` field to `true` * `logrus.JSONFormatter`. Logs fields as JSON. +* `logrus_logstash.LogstashFormatter`. Logs fields as Logstash Events (http://logstash.net). + + ```go + logrus.SetFormatter(&logrus_logstash.LogstashFormatter{Type: “application_name"}) + ``` Third party logging formatters: diff --git a/formatters/logstash/logstash.go b/formatters/logstash/logstash.go new file mode 100644 index 0000000..34b1ccb --- /dev/null +++ b/formatters/logstash/logstash.go @@ -0,0 +1,48 @@ +package logstash + +import ( + "encoding/json" + "fmt" + "github.com/Sirupsen/logrus" + "time" +) + +// Formatter generates json in logstash format. +// Logstash site: http://logstash.net/ +type LogstashFormatter struct { + Type string // if not empty use for logstash type field. +} + +func (f *LogstashFormatter) Format(entry *logrus.Entry) ([]byte, error) { + entry.Data["@version"] = 1 + entry.Data["@timestamp"] = entry.Time.Format(time.RFC3339) + + // set message field + v, ok := entry.Data["message"] + if ok { + entry.Data["fields.message"] = v + } + entry.Data["message"] = entry.Message + + // set level field + v, ok = entry.Data["level"] + if ok { + entry.Data["fields.level"] = v + } + entry.Data["level"] = entry.Level.String() + + // set type field + if f.Type != "" { + v, ok = entry.Data["type"] + if ok { + entry.Data["fields.type"] = v + } + entry.Data["type"] = f.Type + } + + serialized, err := json.Marshal(entry.Data) + if err != nil { + return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err) + } + return append(serialized, '\n'), nil +} diff --git a/formatters/logstash/logstash_test.go b/formatters/logstash/logstash_test.go new file mode 100644 index 0000000..d8814a0 --- /dev/null +++ b/formatters/logstash/logstash_test.go @@ -0,0 +1,52 @@ +package logstash + +import ( + "bytes" + "encoding/json" + "github.com/Sirupsen/logrus" + "github.com/stretchr/testify/assert" + "testing" +) + +func TestLogstashFormatter(t *testing.T) { + assert := assert.New(t) + + lf := LogstashFormatter{Type: "abc"} + + fields := logrus.Fields{ + "message": "def", + "level": "ijk", + "type": "lmn", + "one": 1, + "pi": 3.14, + "bool": true, + } + + entry := logrus.WithFields(fields) + entry.Message = "msg" + entry.Level = logrus.InfoLevel + + b, _ := lf.Format(entry) + + var data map[string]interface{} + dec := json.NewDecoder(bytes.NewReader(b)) + dec.UseNumber() + dec.Decode(&data) + + // base fields + assert.Equal(json.Number("1"), data["@version"]) + assert.NotEmpty(data["@timestamp"]) + assert.Equal("abc", data["type"]) + assert.Equal("msg", data["message"]) + assert.Equal("info", data["level"]) + + // substituted fields + assert.Equal("def", data["fields.message"]) + assert.Equal("ijk", data["fields.level"]) + assert.Equal("lmn", data["fields.type"]) + + // formats + assert.Equal(json.Number("1"), data["one"]) + assert.Equal(json.Number("3.14"), data["pi"]) + assert.Equal(true, data["bool"]) +}