Add date offset option to date processor

CHANGELOG.md

@@ -6,6 +6,9 @@
   renamed to `sqlserver_azure_db_resource_stats` due to an issue where numeric
   metrics were previously being reported incorrectly as strings.
 
+- The `date` processor now uses the UTC timezone when creating its tag.  In
+  previous versions the local time was used.
+
 #### New Outputs
 
 - [warp10](/plugins/outputs/warp10/README.md) - Contributed by @aurrelhebert

plugins/processors/date/README.md

@@ -19,6 +19,23 @@ A few example usecases include:
   ## Date format string, must be a representation of the Go "reference time"
   ## which is "Mon Jan 2 15:04:05 -0700 MST 2006".
   date_format = "Jan"
+
+  ## Offset duration added to the date string when writing the new tag.
+  # date_offset = "0s"
+
+  ## Timezone to use when generating the date.  This can be set to one of
+  ## "Local", "UTC", or to a location name in the IANA Time Zone database.
+  ##   example: timezone = "America/Los_Angeles"
+  # timezone = "UTC"
+```
+
+#### timezone
+
+On Windows, only the `Local` and `UTC` zones are available by default.  To use
+other timezones, set the `ZONEINFO` environment variable to the location of
+[`zoneinfo.zip`][zoneinfo]:
+```
+set ZONEINFO=C:\zoneinfo.zip
 ```
 
 ### Example
@@ -27,3 +44,5 @@ A few example usecases include:
 - throughput lower=10i,upper=1000i,mean=500i 1560540094000000000
 + throughput,month=Jun lower=10i,upper=1000i,mean=500i 1560540094000000000
 ```
+
+[zoneinfo]: https://github.com/golang/go/raw/50bd1c4d4eb4fac8ddeb5f063c099daccfb71b26/lib/time/zoneinfo.zip

plugins/processors/date/date.go

@@ -1,7 +1,10 @@
 package date
 
 import (
+	"time"
+
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/processors"
 )
 
@@ -12,11 +15,25 @@ const sampleConfig = `
   ## Date format string, must be a representation of the Go "reference time"
   ## which is "Mon Jan 2 15:04:05 -0700 MST 2006".
   date_format = "Jan"
+
+  ## Offset duration added to the date string when writing the new tag.
+  # date_offset = "0s"
+
+  ## Timezone to use when creating the tag.  This can be set to one of
+  ## "UTC", "Local", or to a location name in the IANA Time Zone database.
+  ##   example: timezone = "America/Los_Angeles"
+  # timezone = "UTC"
 `
 
+const defaultTimezone = "UTC"
+
 type Date struct {
-	TagKey     string `toml:"tag_key"`
-	DateFormat string `toml:"date_format"`
+	TagKey     string            `toml:"tag_key"`
+	DateFormat string            `toml:"date_format"`
+	DateOffset internal.Duration `toml:"date_offset"`
+	Timezone   string            `toml:"timezone"`
+
+	location *time.Location
 }
 
 func (d *Date) SampleConfig() string {
@@ -27,16 +44,26 @@ func (d *Date) Description() string {
 	return "Dates measurements, tags, and fields that pass through this filter."
 }
 
+func (d *Date) Init() error {
+	var err error
+	// LoadLocation returns UTC if timezone is the empty string.
+	d.location, err = time.LoadLocation(d.Timezone)
+	return err
+}
+
 func (d *Date) Apply(in ...telegraf.Metric) []telegraf.Metric {
 	for _, point := range in {
-		point.AddTag(d.TagKey, point.Time().Format(d.DateFormat))
+		tm := point.Time().In(d.location).Add(d.DateOffset.Duration)
+		point.AddTag(d.TagKey, tm.Format(d.DateFormat))
 	}
 
 	return in
 }
 
 func init() {
 	processors.Add("date", func() telegraf.Processor {
-		return &Date{}
+		return &Date{
+			Timezone: defaultTimezone,
+		}
 	})
 }

plugins/processors/date/date_test.go

@@ -5,8 +5,11 @@ import (
 	"time"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/metric"
+	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func MustMetric(name string, tags map[string]string, fields map[string]interface{}, metricTime time.Time) telegraf.Metric {
@@ -25,6 +28,8 @@ func TestMonthTag(t *testing.T) {
 		TagKey:     "month",
 		DateFormat: "Jan",
 	}
+	err := dateFormatMonth.Init()
+	require.NoError(t, err)
 
 	currentTime := time.Now()
 	month := currentTime.Format("Jan")
@@ -43,6 +48,10 @@ func TestYearTag(t *testing.T) {
 		TagKey:     "year",
 		DateFormat: "2006",
 	}
+
+	err := dateFormatYear.Init()
+	require.NoError(t, err)
+
 	currentTime := time.Now()
 	year := currentTime.Format("2006")
 
@@ -61,7 +70,46 @@ func TestOldDateTag(t *testing.T) {
 		DateFormat: "2006",
 	}
 
+	err := dateFormatYear.Init()
+	require.NoError(t, err)
+
 	m7 := MustMetric("foo", nil, nil, time.Date(1993, 05, 27, 0, 0, 0, 0, time.UTC))
 	customDateApply := dateFormatYear.Apply(m7)
 	assert.Equal(t, map[string]string{"year": "1993"}, customDateApply[0].Tags(), "should add tag 'year'")
 }
+
+func TestDateOffset(t *testing.T) {
+	plugin := &Date{
+		TagKey:     "hour",
+		DateFormat: "15",
+		DateOffset: internal.Duration{Duration: 2 * time.Hour},
+	}
+
+	err := plugin.Init()
+	require.NoError(t, err)
+
+	metric := testutil.MustMetric(
+		"cpu",
+		map[string]string{},
+		map[string]interface{}{
+			"time_idle": 42.0,
+		},
+		time.Unix(1578603600, 0),
+	)
+
+	expected := []telegraf.Metric{
+		testutil.MustMetric(
+			"cpu",
+			map[string]string{
+				"hour": "23",
+			},
+			map[string]interface{}{
+				"time_idle": 42.0,
+			},
+			time.Unix(1578603600, 0),
+		),
+	}
+
+	actual := plugin.Apply(metric)
+	testutil.RequireMetricsEqual(t, expected, actual)
+}