diff --git a/json_formatter.go b/json_formatter.go index 2ad6dc5..f3729bf 100644 --- a/json_formatter.go +++ b/json_formatter.go @@ -5,9 +5,37 @@ import ( "fmt" ) +type fieldKey string +type FieldMap map[fieldKey]string + +const ( + FieldKeyMsg = "msg" + FieldKeyLevel = "level" + FieldKeyTime = "time" +) + +func (f FieldMap) resolve(key fieldKey) string { + if k, ok := f[key]; ok { + return k + } + + return string(key) +} + type JSONFormatter struct { // TimestampFormat sets the format used for marshaling timestamps. TimestampFormat string + + // FieldMap allows users to customize the names of keys for various fields. + // As an example: + // formatter := &JSONFormatter{ + // FieldMap: FieldMap{ + // FieldKeyTime: "@timestamp", + // FieldKeyLevel: "@level", + // FieldKeyLevel: "@message", + // }, + // } + FieldMap FieldMap } func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) { @@ -29,9 +57,9 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) { timestampFormat = DefaultTimestampFormat } - data["time"] = entry.Time.Format(timestampFormat) - data["msg"] = entry.Message - data["level"] = entry.Level.String() + data[f.FieldMap.resolve(FieldKeyTime)] = entry.Time.Format(timestampFormat) + data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message + data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String() serialized, err := json.Marshal(data) if err != nil { diff --git a/json_formatter_test.go b/json_formatter_test.go index 1d70873..5baa93e 100644 --- a/json_formatter_test.go +++ b/json_formatter_test.go @@ -3,7 +3,7 @@ package logrus import ( "encoding/json" "errors" - + "strings" "testing" ) @@ -118,3 +118,54 @@ func TestJSONEntryEndsWithNewline(t *testing.T) { t.Fatal("Expected JSON log entry to end with a newline") } } + +func TestJSONMessageKey(t *testing.T) { + formatter := &JSONFormatter{ + FieldMap: FieldMap{ + FieldKeyMsg: "message", + }, + } + + b, err := formatter.Format(&Entry{Message: "oh hai"}) + if err != nil { + t.Fatal("Unable to format entry: ", err) + } + s := string(b) + if !(strings.Contains(s, "message") && strings.Contains(s, "oh hai")) { + t.Fatal("Expected JSON to format message key") + } +} + +func TestJSONLevelKey(t *testing.T) { + formatter := &JSONFormatter{ + FieldMap: FieldMap{ + FieldKeyLevel: "somelevel", + }, + } + + b, err := formatter.Format(WithField("level", "something")) + if err != nil { + t.Fatal("Unable to format entry: ", err) + } + s := string(b) + if !strings.Contains(s, "somelevel") { + t.Fatal("Expected JSON to format level key") + } +} + +func TestJSONTimeKey(t *testing.T) { + formatter := &JSONFormatter{ + FieldMap: FieldMap{ + FieldKeyTime: "timeywimey", + }, + } + + b, err := formatter.Format(WithField("level", "something")) + if err != nil { + t.Fatal("Unable to format entry: ", err) + } + s := string(b) + if !strings.Contains(s, "timeywimey") { + t.Fatal("Expected JSON to format time key") + } +}