Add telegraf and go version to the internal input plugin (#6216)

plugins/inputs/internal/README.md

@@ -42,14 +42,16 @@ agent stats collect aggregate stats on all telegraf plugins.
     - metrics_written
 
 internal_gather stats collect aggregate stats on all input plugins
-that are of the same input type. They are tagged with `input=<plugin_name>`.
+that are of the same input type. They are tagged with `input=<plugin_name>`
+`version=<telegraf_version>` and `go_version=<go_build_version>`.
 
 - internal_gather
     - gather_time_ns
     - metrics_gathered
 
 internal_write stats collect aggregate stats on all output plugins
-that are of the same input type. They are tagged with `output=<plugin_name>`.
+that are of the same input type. They are tagged with `output=<plugin_name>`
+and `version=<telegraf_version>`.
 
 
 - internal_write
@@ -63,7 +65,7 @@ that are of the same input type. They are tagged with `output=<plugin_name>`.
 
 internal_<plugin_name> are metrics which are defined on a per-plugin basis, and
 usually contain tags which differentiate each instance of a particular type of
-plugin.
+plugin and `version=<telegraf_version>`.
 
 - internal_<plugin_name>
     - individual plugin-specific fields, such as requests counts.
@@ -71,15 +73,16 @@ plugin.
 ### Tags:
 
 All measurements for specific plugins are tagged with information relevant
-to each particular plugin.
+to each particular plugin and with `version=<telegraf_version>`.
+
 
 ### Example Output:
 
 ```
 internal_memstats,host=tyrion alloc_bytes=4457408i,sys_bytes=10590456i,pointer_lookups=7i,mallocs=17642i,frees=7473i,heap_sys_bytes=6848512i,heap_idle_bytes=1368064i,heap_in_use_bytes=5480448i,heap_released_bytes=0i,total_alloc_bytes=6875560i,heap_alloc_bytes=4457408i,heap_objects_bytes=10169i,num_gc=2i 1480682800000000000
-internal_agent,host=tyrion metrics_written=18i,metrics_dropped=0i,metrics_gathered=19i,gather_errors=0i 1480682800000000000
-internal_write,output=file,host=tyrion buffer_limit=10000i,write_time_ns=636609i,metrics_added=18i,metrics_written=18i,buffer_size=0i 1480682800000000000
-internal_gather,input=internal,host=tyrion metrics_gathered=19i,gather_time_ns=442114i 1480682800000000000
-internal_gather,input=http_listener,host=tyrion metrics_gathered=0i,gather_time_ns=167285i 1480682800000000000
-internal_http_listener,address=:8186,host=tyrion queries_received=0i,writes_received=0i,requests_received=0i,buffers_created=0i,requests_served=0i,pings_received=0i,bytes_received=0i,not_founds_served=0i,pings_served=0i,queries_served=0i,writes_served=0i 1480682800000000000
+internal_agent,host=tyrion,go_version=1.12.7,version=1.99.0 metrics_written=18i,metrics_dropped=0i,metrics_gathered=19i,gather_errors=0i 1480682800000000000
+internal_write,output=file,host=tyrion,version=1.99.0 buffer_limit=10000i,write_time_ns=636609i,metrics_added=18i,metrics_written=18i,buffer_size=0i 1480682800000000000
+internal_gather,input=internal,host=tyrion,version=1.99.0 metrics_gathered=19i,gather_time_ns=442114i 1480682800000000000
+internal_gather,input=http_listener,host=tyrion,version=1.99.0 metrics_gathered=0i,gather_time_ns=167285i 1480682800000000000
+internal_http_listener,address=:8186,host=tyrion,version=1.99.0 queries_received=0i,writes_received=0i,requests_received=0i,buffers_created=0i,requests_served=0i,pings_received=0i,bytes_received=0i,not_founds_served=0i,pings_served=0i,queries_served=0i,writes_served=0i 1480682800000000000
 ```

plugins/inputs/internal/internal.go

@@ -2,8 +2,10 @@ package internal
 
 import (
 	"runtime"
+	"strings"
 
 	"github.com/influxdata/telegraf"
+	inter "github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/inputs"
 	"github.com/influxdata/telegraf/selfstat"
 )
@@ -54,7 +56,14 @@ func (s *Self) Gather(acc telegraf.Accumulator) error {
 		acc.AddFields("internal_memstats", fields, map[string]string{})
 	}
 
+	telegrafVersion := inter.Version()
+	goVersion := strings.TrimPrefix(runtime.Version(), "go")
+
 	for _, m := range selfstat.Metrics() {
+		if m.Name() == "internal_agent" {
+			m.AddTag("go_version", goVersion)
+		}
+		m.AddTag("version", telegrafVersion)
 		acc.AddFields(m.Name(), m.Fields(), m.Tags(), m.Time())
 	}
 

plugins/inputs/internal/internal_test.go

@@ -27,6 +27,7 @@ func TestSelfPlugin(t *testing.T) {
 		},
 		map[string]string{
 			"test":    "foo",
+			"version": "",
 		},
 	)
 	acc.ClearMetrics()
@@ -40,6 +41,7 @@ func TestSelfPlugin(t *testing.T) {
 		},
 		map[string]string{
 			"test":    "foo",
+			"version": "",
 		},
 	)
 	acc.ClearMetrics()
@@ -57,6 +59,7 @@ func TestSelfPlugin(t *testing.T) {
 		},
 		map[string]string{
 			"test":    "foo",
+			"version": "",
 		},
 	)
 }