[Docker Plugin] add server hostname for each docker measurements (#1599)

* add server hostname for each docker measurements

* update CHANGELOG

* move feature to v1.1

* tweak docker_engine_host tag

CHANGELOG.md

@@ -15,6 +15,7 @@
 - [#1539](https://github.com/influxdata/telegraf/pull/1539): Added capability to send metrics through Http API for OpenTSDB.
 - [#1471](https://github.com/influxdata/telegraf/pull/1471): iptables input plugin.
 - [#1542](https://github.com/influxdata/telegraf/pull/1542): Add filestack webhook plugin.
+- [#1599](https://github.com/influxdata/telegraf/pull/1599): Add server hostname for each docker measurements.
 
 ### Bugfixes
 

plugins/inputs/docker/docker.go

@@ -28,7 +28,8 @@ type Docker struct {
 	PerDevice      bool `toml:"perdevice"`
 	Total          bool `toml:"total"`
 
-	client DockerClient
+	client      DockerClient
+	engine_host string
 }
 
 // DockerClient interface, useful for testing
@@ -147,6 +148,7 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 	if err != nil {
 		return err
 	}
+	d.engine_host = info.Name
 
 	fields := map[string]interface{}{
 		"n_cpus":                  info.NCPU,
@@ -159,11 +161,11 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 	// Add metrics
 	acc.AddFields("docker",
 		fields,
-		nil,
+		map[string]string{"engine_host": d.engine_host},
 		now)
 	acc.AddFields("docker",
 		map[string]interface{}{"memory_total": info.MemTotal},
-		map[string]string{"unit": "bytes"},
+		map[string]string{"unit": "bytes", "engine_host": d.engine_host},
 		now)
 	// Get storage metrics
 	for _, rawData := range info.DriverStatus {
@@ -177,7 +179,7 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 			// pool blocksize
 			acc.AddFields("docker",
 				map[string]interface{}{"pool_blocksize": value},
-				map[string]string{"unit": "bytes"},
+				map[string]string{"unit": "bytes", "engine_host": d.engine_host},
 				now)
 		} else if strings.HasPrefix(name, "data_space_") {
 			// data space
@@ -192,13 +194,13 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 	if len(dataFields) > 0 {
 		acc.AddFields("docker_data",
 			dataFields,
-			map[string]string{"unit": "bytes"},
+			map[string]string{"unit": "bytes", "engine_host": d.engine_host},
 			now)
 	}
 	if len(metadataFields) > 0 {
 		acc.AddFields("docker_metadata",
 			metadataFields,
-			map[string]string{"unit": "bytes"},
+			map[string]string{"unit": "bytes", "engine_host": d.engine_host},
 			now)
 	}
 	return nil
@@ -225,6 +227,7 @@ func (d *Docker) gatherContainer(
 		imageVersion = imageParts[1]
 	}
 	tags := map[string]string{
+		"engine_host":       d.engine_host,
 		"container_name":    cname,
 		"container_image":   imageName,
 		"container_version": imageVersion,

plugins/inputs/docker/docker_test.go

@@ -400,7 +400,7 @@ func TestDockerGatherInfo(t *testing.T) {
 			"n_images":                int(199),
 			"n_goroutines":            int(39),
 		},
-		map[string]string{},
+		map[string]string{"engine_host": "absol"},
 	)
 
 	acc.AssertContainsTaggedFields(t,
@@ -411,7 +411,8 @@ func TestDockerGatherInfo(t *testing.T) {
 			"available": int64(36530000000),
 		},
 		map[string]string{
-			"unit": "bytes",
+			"unit":        "bytes",
+			"engine_host": "absol",
 		},
 	)
 	acc.AssertContainsTaggedFields(t,
@@ -425,6 +426,7 @@ func TestDockerGatherInfo(t *testing.T) {
 			"container_image":   "quay.io/coreos/etcd",
 			"cpu":               "cpu3",
 			"container_version": "v2.2.2",
+			"engine_host":       "absol",
 		},
 	)
 	acc.AssertContainsTaggedFields(t,
@@ -467,6 +469,7 @@ func TestDockerGatherInfo(t *testing.T) {
 			"container_id":              "b7dfbb9478a6ae55e237d4d74f8bbb753f0817192b5081334dc78476296e2173",
 		},
 		map[string]string{
+			"engine_host":       "absol",
 			"container_name":    "etcd2",
 			"container_image":   "quay.io/coreos/etcd",
 			"container_version": "v2.2.2",