Add support for unix_ms timestamps in csv parser.

plugins/parsers/csv/README.md

@@ -73,10 +73,10 @@ time using the JSON document you can use the `csv_timestamp_column` and
 `csv_timestamp_format` options together to set the time to a value in the parsed
 document.
 
-The `csv_timestamp_column` option specifies the column name containing the
-time value and `csv_timestamp_format` must be set to a Go "reference time"
-which is defined to be the specific time: `Mon Jan 2 15:04:05 MST 2006`, 
-it can also be `unix` (for epoch in ms format like 1257894000 )
+The `csv_timestamp_column` option specifies the key containing the time value and
+`csv_timestamp_format` must be set to `unix`, `unix_ms`, or a format string in
+using the Go "reference time" which is defined to be the **specific time**:
+`Mon Jan 2 15:04:05 MST 2006`.
 
 Consult the Go [time][time parse] package for details and additional examples
 on how to set the time format.

plugins/parsers/csv/parser.go

@@ -219,9 +219,12 @@ outer:
 	return m, nil
 }
 
-// ParseTimestamp return a timestamp, if there is no timestamp on the csv it will be the current timestamp, else it will try to parse the time according to the format
-// if the format is "unix" it tries to parse assuming that on the csv it will find an epoch in ms.
-func parseTimestamp(timeFunc func() time.Time, recordFields map[string]interface{}, timestampColumn, timestampFormat string) (metricTime time.Time, err error) {
+// ParseTimestamp return a timestamp, if there is no timestamp on the csv it
+// will be the current timestamp, else it will try to parse the time according
+// to the format.
+func parseTimestamp(timeFunc func() time.Time, recordFields map[string]interface{},
+	timestampColumn, timestampFormat string,
+) (metricTime time.Time, err error) {
 	metricTime = timeFunc()
 
 	if timestampColumn != "" {
@@ -243,6 +246,13 @@ func parseTimestamp(timeFunc func() time.Time, recordFields map[string]interface
 				return
 			}
 			metricTime = time.Unix(unixTime, 0)
+		case "unix_ms":
+			var unixTime int64
+			unixTime, err = strconv.ParseInt(tStr, 10, 64)
+			if err != nil {
+				return
+			}
+			metricTime = time.Unix(unixTime/1000, (unixTime%1000)*1e6)
 		default:
 			metricTime, err = time.Parse(timestampFormat, tStr)
 			if err != nil {

plugins/parsers/csv/parser_test.go

@@ -106,6 +106,24 @@ func TestTimestampUnixFormat(t *testing.T) {
 	require.Equal(t, metrics[1].Time().UnixNano(), int64(1257609906000000000))
 }
 
+func TestTimestampUnixMSFormat(t *testing.T) {
+	p := Parser{
+		HeaderRowCount:    1,
+		ColumnNames:       []string{"first", "second", "third"},
+		MeasurementColumn: "third",
+		TimestampColumn:   "first",
+		TimestampFormat:   "unix_ms",
+		TimeFunc:          DefaultTime,
+	}
+	testCSV := `line1,line2,line3
+1243094706123,70,test_name
+1257609906123,80,test_name2`
+	metrics, err := p.Parse([]byte(testCSV))
+	require.NoError(t, err)
+	require.Equal(t, metrics[0].Time().UnixNano(), int64(1243094706123000000))
+	require.Equal(t, metrics[1].Time().UnixNano(), int64(1257609906123000000))
+}
+
 func TestQuotedCharacter(t *testing.T) {
 	p := Parser{
 		HeaderRowCount:    1,