[Instrumental] Underscore metric name output (#1607)

* separate hello and authenticate functions, force connection close at end of write cycle so we don't hold open idle connections, which has the benefit of mostly removing the chance of getting hopelessly connection lost

* update changelog, though this will need to be updated again to merge into telegraf master

* bump instrumental agent version

* fix test to deal with better better connect/reconnect logic and changed ident & auth handshake

* Update CHANGELOG.md

correct URL from instrumental fork to origin and put the change in the correct part of the file

* go fmt

* Split out Instrumental tests for invalid metric and value.

* Ensure nothing remains on the wire after final test.

* Force valid metric names by replacing invalid parts with underscores.

* Multiple invalid characters being joined into a single udnerscore.

* Adjust comment to what happens.

* undo split hello and auth commands, to reduce roundtrips

* Split out Instrumental tests for invalid metric and value.

* Ensure nothing remains on the wire after final test.

* Force valid metric names by replacing invalid parts with underscores.

* Multiple invalid characters being joined into a single udnerscore.

* add an entry to CHANGELOG for easy merging upstream

* go fmt variable alignment

* remove some bugfixes from changelog which now more properly are in a different section.

* remove headers and whitespace should should have been removed with the last commit

CHANGELOG.md

@@ -147,6 +147,7 @@ consistent with the behavior of `collection_jitter`.
 - [#1323](https://github.com/influxdata/telegraf/issues/1323): Processes plugin: fix potential error with /proc/net/stat directory.
 - [#1322](https://github.com/influxdata/telegraf/issues/1322): Fix rare RHEL 5.2 panic in gopsutil diskio gathering function.
 - [#1586](https://github.com/influxdata/telegraf/pull/1586): Remove IF NOT EXISTS from influxdb output database creation.
+- [#1607](https://github.com/influxdata/telegraf/pull/1607): Massage metric names in Instrumental output plugin
 - [#1600](https://github.com/influxdata/telegraf/issues/1600): Fix quoting with text values in postgresql_extensible plugin.
 - [#1425](https://github.com/influxdata/telegraf/issues/1425): Fix win_perf_counter "index out of range" panic.
 - [#1634](https://github.com/influxdata/telegraf/issues/1634): Fix ntpq panic when field is missing.

plugins/outputs/instrumental/instrumental.go

@@ -35,7 +35,8 @@ const (
 )
 
 var (
-	StatIncludesBadChar = regexp.MustCompile("[^[:alnum:][:blank:]-_.]")
+	ValueIncludesBadChar = regexp.MustCompile("[^[:digit:].]")
+	MetricNameReplacer   = regexp.MustCompile("[^-[:alnum:]_.]+")
 )
 
 var sampleConfig = `
@@ -131,8 +132,17 @@ func (i *Instrumental) Write(metrics []telegraf.Metric) error {
 		}
 
 		for _, stat := range stats {
-			if !StatIncludesBadChar.MatchString(stat) {
-				points = append(points, fmt.Sprintf("%s %s", metricType, stat))
+			// decompose "metric.name value time"
+			splitStat := strings.SplitN(stat, " ", 3)
+			metric := splitStat[0]
+			value := splitStat[1]
+			time := splitStat[2]
+
+			// replace invalid components of metric name with underscore
+			clean_metric := MetricNameReplacer.ReplaceAllString(metric, "_")
+
+			if !ValueIncludesBadChar.MatchString(value) {
+				points = append(points, fmt.Sprintf("%s %s %s %s", metricType, clean_metric, value, time))
 			} else if i.Debug {
 				log.Printf("Unable to send bad stat: %s", stat)
 			}

plugins/outputs/instrumental/instrumental_test.go

@@ -49,21 +49,28 @@ func TestWrite(t *testing.T) {
 		map[string]interface{}{"value": float64(3.14)},
 		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
 	)
-	// We will drop metrics that simply won't be accepted by Instrumental
+	// We will modify metric names that won't be accepted by Instrumental
 	m4, _ := telegraf.NewMetric(
+		"bad_metric_name",
+		map[string]string{"host": "192.168.0.1:8888::123", "metric_type": "counter"},
+		map[string]interface{}{"value": 1},
+		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
+	)
+	// We will drop metric values that won't be accepted by Instrumental
+	m5, _ := telegraf.NewMetric(
 		"bad_values",
 		map[string]string{"host": "192.168.0.1", "metric_type": "counter"},
 		map[string]interface{}{"value": "\" 3:30\""},
 		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
 	)
-	m5, _ := telegraf.NewMetric(
+	m6, _ := telegraf.NewMetric(
 		"my_counter",
 		map[string]string{"host": "192.168.0.1", "metric_type": "counter"},
 		map[string]interface{}{"value": float64(3.14)},
 		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
 	)
 
-	metrics = []telegraf.Metric{m3, m4, m5}
+	metrics = []telegraf.Metric{m3, m4, m5, m6}
 	i.Write(metrics)
 
 	wg.Wait()
@@ -101,8 +108,15 @@ func TCPServer(t *testing.T, wg *sync.WaitGroup) {
 
 	data3, _ := tp.ReadLine()
 	assert.Equal(t, "increment my.prefix.192_168_0_1.my_histogram 3.14 1289430000", data3)
+
 	data4, _ := tp.ReadLine()
-	assert.Equal(t, "increment my.prefix.192_168_0_1.my_counter 3.14 1289430000", data4)
+	assert.Equal(t, "increment my.prefix.192_168_0_1_8888_123.bad_metric_name 1 1289430000", data4)
+
+	data5, _ := tp.ReadLine()
+	assert.Equal(t, "increment my.prefix.192_168_0_1.my_counter 3.14 1289430000", data5)
+
+	data6, _ := tp.ReadLine()
+	assert.Equal(t, "", data6)
 
 	conn.Close()
 }