Implement telegraf collecting stats on itself

closes #1348

internal/models/running_input.go

@@ -5,15 +5,34 @@ import (
 	"time"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/selfstat"
 )
 
+var GlobalMetricsGathered = selfstat.Register("agent", "metrics_gathered", map[string]string{})
+
 type RunningInput struct {
 	Input  telegraf.Input
 	Config *InputConfig
 
 	trace       bool
-	debug       bool
 	defaultTags map[string]string
+
+	MetricsGathered selfstat.Stat
+}
+
+func NewRunningInput(
+	input telegraf.Input,
+	config *InputConfig,
+) *RunningInput {
+	return &RunningInput{
+		Input:  input,
+		Config: config,
+		MetricsGathered: selfstat.Register(
+			"gather",
+			"metrics_gathered",
+			map[string]string{"input": config.Name},
+		),
+	}
 }
 
 // InputConfig containing a name, interval, and filter
@@ -51,7 +70,6 @@ func (r *RunningInput) MakeMetric(
 		r.defaultTags,
 		r.Config.Filter,
 		true,
-		r.debug,
 		mType,
 		t,
 	)
@@ -60,17 +78,11 @@ func (r *RunningInput) MakeMetric(
 		fmt.Println("> " + m.String())
 	}
 
+	r.MetricsGathered.Incr(1)
+	GlobalMetricsGathered.Incr(1)
 	return m
 }
 
-func (r *RunningInput) Debug() bool {
-	return r.debug
-}
-
-func (r *RunningInput) SetDebug(debug bool) {
-	r.debug = debug
-}
-
 func (r *RunningInput) Trace() bool {
 	return r.trace
 }