Add container id as optional source tag to docker and docker_log input (#6473)

plugins/inputs/docker/README.md

@@ -26,6 +26,9 @@ to gather stats from the [Engine API](https://docs.docker.com/engine/api/v1.24/)
   ## Deprecated (1.4.0), use container_name_include
   container_names = []
 
+  ## Set the source tag for the metrics to the container ID hostname, eg first 12 chars
+  source_tag = false
+
   ## Containers to include and exclude. Collect all if empty. Globs accepted.
   container_name_include = []
   container_name_exclude = []
@@ -93,6 +96,17 @@ volumes:
   - /var/run/docker.sock:/var/run/docker.sock
 ```
 
+#### source tag
+
+Selecting the containers measurements can be tricky if you have many containers with the same name.
+To alleviate this issue you can set the below value to `true`
+
+```toml
+source_tag = true
+```
+
+This will cause all measurements to have the `source` tag be set to the first 12 characters of the container id. The first 12 characters is the common hostname for containers that have no explicit hostname set, as defined by docker.
+
 #### Kubernetes Labels
 
 Kubernetes may add many labels to your containers, if they are not needed you

plugins/inputs/docker/docker.go

@@ -44,6 +44,8 @@ type Docker struct {
 	ContainerStateInclude []string `toml:"container_state_include"`
 	ContainerStateExclude []string `toml:"container_state_exclude"`
 
+	IncludeSourceTag bool `toml:"source_tag"`
+
 	Log telegraf.Logger
 
 	tlsint.ClientConfig
@@ -90,6 +92,9 @@ var sampleConfig = `
   ## Only collect metrics for these containers, collect all if empty
   container_names = []
 
+  ## Set the source tag for the metrics to the container ID hostname, eg first 12 chars
+  source_tag = false
+
   ## Containers to include and exclude. Globs accepted.
   ## Note that an empty array for both will include all containers
   container_name_include = []
@@ -412,6 +417,13 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 	return nil
 }
 
+func hostnameFromID(id string) string {
+	if len(id) > 12 {
+		return id[0:12]
+	}
+	return id
+}
+
 func (d *Docker) gatherContainer(
 	container types.Container,
 	acc telegraf.Accumulator,
@@ -443,6 +455,10 @@ func (d *Docker) gatherContainer(
 		"container_version": imageVersion,
 	}
 
+	if d.IncludeSourceTag {
+		tags["source"] = hostnameFromID(container.ID)
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), d.Timeout.Duration)
 	defer cancel()
 

plugins/inputs/docker/docker_test.go

@@ -631,6 +631,7 @@ func TestContainerStatus(t *testing.T) {
 				d = Docker{
 					Log:              testutil.Logger{},
 					newClient:        newClientFunc,
+					IncludeSourceTag: true,
 				}
 			)
 
@@ -673,6 +674,7 @@ func TestContainerStatus(t *testing.T) {
 					"label2":            "test_value_2",
 					"server_version":    "17.09.0-ce",
 					"container_status":  tt.expect.Status,
+					"source":            "e2173b9478a6",
 				})
 		})
 	}
@@ -1017,3 +1019,37 @@ func TestContainerName(t *testing.T) {
 		})
 	}
 }
+
+func TestHostnameFromID(t *testing.T) {
+	tests := []struct {
+		name   string
+		id     string
+		expect string
+	}{
+		{
+			name:   "Real ID",
+			id:     "565e3a55f5843cfdd4aa5659a1a75e4e78d47f73c3c483f782fe4a26fc8caa07",
+			expect: "565e3a55f584",
+		},
+		{
+			name:   "Short ID",
+			id:     "shortid123",
+			expect: "shortid123",
+		},
+		{
+			name:   "No ID",
+			id:     "",
+			expect: "shortid123",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			output := hostnameFromID(test.id)
+			if test.expect != output {
+				t.Logf("Container ID for hostname is wrong. Want: %s, Got: %s", output, test.expect)
+			}
+		})
+	}
+
+}

plugins/inputs/docker_log/README.md

@@ -43,6 +43,9 @@ The docker plugin uses the [Official Docker Client][] to gather logs from the
   # docker_label_include = []
   # docker_label_exclude = []
 
+  ## Set the source tag for the metrics to the container ID hostname, eg first 12 chars
+  source_tag = false
+
   ## Optional TLS Config
   # tls_ca = "/etc/telegraf/ca.pem"
   # tls_cert = "/etc/telegraf/cert.pem"
@@ -58,6 +61,17 @@ When using the `"ENV"` endpoint, the connection is configured using the
 
 [env]: https://godoc.org/github.com/moby/moby/client#NewEnvClient
 
+### source tag
+
+Selecting the containers can be tricky if you have many containers with the same name.
+To alleviate this issue you can set the below value to `true`
+
+```toml
+source_tag = true
+```
+
+This will cause all data points to have the `source` tag be set to the first 12 characters of the container id. The first 12 characters is the common hostname for containers that have no explicit hostname set, as defined by docker.
+
 ### Metrics
 
 - docker_log
@@ -66,6 +80,7 @@ When using the `"ENV"` endpoint, the connection is configured using the
     - container_version
     - container_name
     - stream (stdout, stderr, or tty)
+    - source
   - fields:
     - container_id
     - message

plugins/inputs/docker_log/docker_log.go

@@ -49,6 +49,9 @@ var sampleConfig = `
   # docker_label_include = []
   # docker_label_exclude = []
 
+  ## Set the source tag for the metrics to the container ID hostname, eg first 12 chars
+  source_tag = false
+
   ## Optional TLS Config
   # tls_ca = "/etc/telegraf/ca.pem"
   # tls_cert = "/etc/telegraf/cert.pem"
@@ -82,6 +85,7 @@ type DockerLogs struct {
 	ContainerExclude      []string          `toml:"container_name_exclude"`
 	ContainerStateInclude []string          `toml:"container_state_include"`
 	ContainerStateExclude []string          `toml:"container_state_exclude"`
+	IncludeSourceTag      bool              `toml:"source_tag"`
 
 	tlsint.ClientConfig
 
@@ -258,6 +262,10 @@ func (d *DockerLogs) tailContainerLogs(
 		"container_version": imageVersion,
 	}
 
+	if d.IncludeSourceTag {
+		tags["source"] = hostnameFromID(container.ID)
+	}
+
 	// Add matching container labels as tags
 	for k, label := range container.Labels {
 		if d.labelFilter.Match(k) {
@@ -435,3 +443,10 @@ func init() {
 		}
 	})
 }
+
+func hostnameFromID(id string) string {
+	if len(id) > 12 {
+		return id[0:12]
+	}
+	return id
+}

plugins/inputs/docker_log/docker_log_test.go

@@ -98,6 +98,7 @@ func Test(t *testing.T) {
 						"container_image":   "influxdata/telegraf",
 						"container_version": "1.11.0",
 						"stream":            "tty",
+						"source":            "deadbeef",
 					},
 					map[string]interface{}{
 						"container_id": "deadbeef",
@@ -141,6 +142,7 @@ func Test(t *testing.T) {
 						"container_image":   "influxdata/telegraf",
 						"container_version": "1.11.0",
 						"stream":            "stdout",
+						"source":            "deadbeef",
 					},
 					map[string]interface{}{
 						"container_id": "deadbeef",
@@ -158,6 +160,7 @@ func Test(t *testing.T) {
 				Timeout:          internal.Duration{Duration: time.Second * 5},
 				newClient:        func(string, *tls.Config) (Client, error) { return tt.client, nil },
 				containerList:    make(map[string]context.CancelFunc),
+				IncludeSourceTag: true,
 			}
 
 			err := plugin.Init()