Add csv parser unix timestamp support (influxdata#5047)

plugins/parsers/csv/README.md

@@ -75,7 +75,8 @@ 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`.
+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 )
 
 Consult the Go [time][time parse] package for details and additional examples
 on how to set the time format.

plugins/parsers/csv/parser.go

@@ -207,21 +207,9 @@ outer:
 		measurementName = fmt.Sprintf("%v", recordFields[p.MeasurementColumn])
 	}
 
-	metricTime := p.TimeFunc()
-	if p.TimestampColumn != "" {
-		if recordFields[p.TimestampColumn] == nil {
-			return nil, fmt.Errorf("timestamp column: %v could not be found", p.TimestampColumn)
-		}
-		tStr := fmt.Sprintf("%v", recordFields[p.TimestampColumn])
-		if p.TimestampFormat == "" {
-			return nil, fmt.Errorf("timestamp format must be specified")
-		}
-
-		var err error
-		metricTime, err = time.Parse(p.TimestampFormat, tStr)
-		if err != nil {
-			return nil, err
-		}
+	metricTime, err := parseTimestamp(p.TimeFunc, recordFields, p.TimestampColumn, p.TimestampFormat)
+	if err != nil {
+		return nil, err
 	}
 
 	m, err := metric.New(measurementName, tags, recordFields, metricTime)
@@ -231,6 +219,41 @@ 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) {
+	metricTime = timeFunc()
+
+	if timestampColumn != "" {
+		if recordFields[timestampColumn] == nil {
+			err = fmt.Errorf("timestamp column: %v could not be found", timestampColumn)
+			return
+		}
+
+		tStr := fmt.Sprintf("%v", recordFields[timestampColumn])
+
+		switch timestampFormat {
+		case "":
+			err = fmt.Errorf("timestamp format must be specified")
+			return
+		case "unix":
+			var unixTime int64
+			unixTime, err = strconv.ParseInt(tStr, 10, 64)
+			if err != nil {
+				return
+			}
+			metricTime = time.Unix(unixTime, 0)
+		default:
+			metricTime, err = time.Parse(timestampFormat, tStr)
+			if err != nil {
+				return
+			}
+		}
+	}
+	return
+}
+
+// SetDefaultTags set the DefaultTags
 func (p *Parser) SetDefaultTags(tags map[string]string) {
 	p.DefaultTags = tags
 }

plugins/parsers/csv/parser_test.go

@@ -88,6 +88,24 @@ func TestTimestampError(t *testing.T) {
 	require.Equal(t, fmt.Errorf("timestamp format must be specified"), err)
 }
 
+func TestTimestampUnixFormat(t *testing.T) {
+	p := Parser{
+		HeaderRowCount:    1,
+		ColumnNames:       []string{"first", "second", "third"},
+		MeasurementColumn: "third",
+		TimestampColumn:   "first",
+		TimestampFormat:   "unix",
+		TimeFunc:          DefaultTime,
+	}
+	testCSV := `line1,line2,line3
+1243094706,70,test_name
+1257609906,80,test_name2`
+	metrics, err := p.Parse([]byte(testCSV))
+	require.NoError(t, err)
+	require.Equal(t, metrics[0].Time().UnixNano(), int64(1243094706000000000))
+	require.Equal(t, metrics[1].Time().UnixNano(), int64(1257609906000000000))
+}
+
 func TestQuotedCharacter(t *testing.T) {
 	p := Parser{
 		HeaderRowCount:    1,