Add Kubernetes metadata from env vars

env_test.go

@@ -186,40 +186,13 @@ func testTracerSanitizeFieldNamesEnv(t *testing.T, envValue, expect string) {
 }
 
 func TestTracerServiceNameEnvSanitizationSpecified(t *testing.T) {
-	testTracerServiceNameSanitization(
-		t, "foo_bar", "ELASTIC_APM_SERVICE_NAME=foo!bar",
-	)
+	_, _, service := getSubprocessMetadata(t, "ELASTIC_APM_SERVICE_NAME=foo!bar")
+	assert.Equal(t, "foo_bar", service.Name)
 }
 
 func TestTracerServiceNameEnvSanitizationExecutableName(t *testing.T) {
-	testTracerServiceNameSanitization(
-		t, "apm_test", // .test -> _test
-	)
-}
-
-func testTracerServiceNameSanitization(t *testing.T, sanitizedServiceName string, env ...string) {
-	if os.Getenv("_INSIDE_TEST") != "1" {
-		cmd := exec.Command(os.Args[0], "-test.run=^"+t.Name()+"$")
-		cmd.Env = append(os.Environ(), "_INSIDE_TEST=1")
-		cmd.Env = append(cmd.Env, env...)
-		output, err := cmd.CombinedOutput()
-		if !assert.NoError(t, err) {
-			t.Logf("output:\n%s", output)
-		}
-		return
-	}
-
-	var transport transporttest.RecorderTransport
-	tracer, _ := apm.NewTracer("", "")
-	tracer.Transport = &transport
-	defer tracer.Close()
-
-	tx := tracer.StartTransaction("name", "type")
-	tx.End()
-	tracer.Flush(nil)
-
-	_, _, service := transport.Metadata()
-	assert.Equal(t, sanitizedServiceName, service.Name)
+	_, _, service := getSubprocessMetadata(t)
+	assert.Equal(t, "apm_test", service.Name) // .test -> _test
 }
 
 func TestTracerCaptureBodyEnv(t *testing.T) {

model/model.go

@@ -85,6 +85,9 @@ type System struct {
 
 	// Container describes the container running the service.
 	Container *Container `json:"container,omitempty"`
+
+	// Kubernetes describes the kubernetes node and pod running the service.
+	Kubernetes *Kubernetes `json:"kubernetes,omitempty"`
 }
 
 // Process represents an operating system process.
@@ -108,6 +111,34 @@ type Container struct {
 	ID string `json:"id"`
 }
 
+// Kubernetes describes properties of the Kubernetes node and pod in which
+// the service is running.
+type Kubernetes struct {
+	// Namespace names the Kubernetes namespace in which the pod exists.
+	Namespace string `json:"namespace,omitempty"`
+
+	// Node describes the Kubernetes node running the service's pod.
+	Node *KubernetesNode `json:"node,omitempty"`
+
+	// Pod describes the Kubernetes pod running the service.
+	Pod *KubernetesPod `json:"pod,omitempty"`
+}
+
+// KubernetesNode describes a Kubernetes node.
+type KubernetesNode struct {
+	// Name holds the node name.
+	Name string `json:"name,omitempty"`
+}
+
+// KubernetesPod describes a Kubernetes pod.
+type KubernetesPod struct {
+	// Name holds the pod name.
+	Name string `json:"name,omitempty"`
+
+	// UID holds the pod UID.
+	UID string `json:"uid,omitempty"`
+}
+
 // Transaction represents a transaction handled by the service.
 type Transaction struct {
 	// ID holds the 64-bit hex-encoded transaction ID.

testmain_test.go

@@ -0,0 +1,77 @@
+package apm_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.elastic.co/apm"
+	"go.elastic.co/apm/model"
+	"go.elastic.co/apm/transport/transporttest"
+	"go.elastic.co/fastjson"
+)
+
+var (
+	flagDumpMetadata = flag.Bool("dump-metadata", false, "Dump metadata and exit without running any tests")
+)
+
+func TestMain(m *testing.M) {
+	// call flag.Parse() here if TestMain uses flags
+	flag.Parse()
+	if *flagDumpMetadata {
+		dumpMetadata()
+		os.Exit(0)
+	}
+	os.Exit(m.Run())
+}
+
+func getSubprocessMetadata(t *testing.T, env ...string) (*model.System, *model.Process, *model.Service) {
+	cmd := exec.Command(os.Args[0], "-dump-metadata")
+	cmd.Env = append(os.Environ(), env...)
+
+	var stdout bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = os.Stderr
+	if !assert.NoError(t, cmd.Run()) {
+		t.FailNow()
+	}
+
+	var system model.System
+	var process model.Process
+	var service model.Service
+
+	output := stdout.String()
+	d := json.NewDecoder(&stdout)
+	if !assert.NoError(t, d.Decode(&system)) {
+		t.Logf("output: %q", output)
+		t.FailNow()
+	}
+	require.NoError(t, d.Decode(&process))
+	require.NoError(t, d.Decode(&service))
+	return &system, &process, &service
+}
+
+func dumpMetadata() {
+	var transport transporttest.RecorderTransport
+	tracer, _ := apm.NewTracer("", "")
+	defer tracer.Close()
+	tracer.Transport = &transport
+
+	tracer.StartTransaction("name", "type").End()
+	tracer.Flush(nil)
+	system, process, service := transport.Metadata()
+
+	var w fastjson.Writer
+	for _, m := range []fastjson.Marshaler{&system, &process, &service} {
+		if err := m.MarshalFastJSON(&w); err != nil {
+			panic(err)
+		}
+	}
+	os.Stdout.Write(w.Bytes())
+}

tracer_test.go

@@ -21,6 +21,7 @@ import (
 
 	"go.elastic.co/apm"
 	"go.elastic.co/apm/internal/apmhostutil"
+	"go.elastic.co/apm/model"
 	"go.elastic.co/apm/transport"
 	"go.elastic.co/apm/transport/transporttest"
 )
@@ -371,6 +372,39 @@ func TestTracerMetadata(t *testing.T) {
 	}
 }
 
+func TestTracerKubernetesMetadata(t *testing.T) {
+	t.Run("no-env", func(t *testing.T) {
+		system, _, _ := getSubprocessMetadata(t)
+		assert.Nil(t, system.Kubernetes)
+	})
+
+	t.Run("namespace-only", func(t *testing.T) {
+		system, _, _ := getSubprocessMetadata(t, "KUBERNETES_NAMESPACE=myapp")
+		assert.Equal(t, &model.Kubernetes{
+			Namespace: "myapp",
+		}, system.Kubernetes)
+	})
+
+	t.Run("pod-only", func(t *testing.T) {
+		system, _, _ := getSubprocessMetadata(t, "KUBERNETES_POD_NAME=luna", "KUBERNETES_POD_UID=oneone!11")
+		assert.Equal(t, &model.Kubernetes{
+			Pod: &model.KubernetesPod{
+				Name: "luna",
+				UID:  "oneone!11",
+			},
+		}, system.Kubernetes)
+	})
+
+	t.Run("node-only", func(t *testing.T) {
+		system, _, _ := getSubprocessMetadata(t, "KUBERNETES_NODE_NAME=noddy")
+		assert.Equal(t, &model.Kubernetes{
+			Node: &model.KubernetesNode{
+				Name: "noddy",
+			},
+		}, system.Kubernetes)
+	})
+}
+
 type blockedTransport struct {
 	transport.Transport
 	unblocked chan struct{}

utils.go

@@ -80,9 +80,35 @@ func getLocalSystem() model.System {
 			ID: containerID,
 		}
 	}
+	system.Kubernetes = getKubernetesMetadata()
 	return system
 }
 
+func getKubernetesMetadata() *model.Kubernetes {
+	namespace := os.Getenv("KUBERNETES_NAMESPACE")
+	podName := os.Getenv("KUBERNETES_POD_NAME")
+	podUID := os.Getenv("KUBERNETES_POD_UID")
+	nodeName := os.Getenv("KUBERNETES_NODE_NAME")
+	if namespace == "" && podName == "" && podUID == "" && nodeName == "" {
+		return nil
+	}
+	k := model.Kubernetes{
+		Namespace: namespace,
+	}
+	if nodeName != "" {
+		k.Node = &model.KubernetesNode{
+			Name: nodeName,
+		}
+	}
+	if podName != "" || podUID != "" {
+		k.Pod = &model.KubernetesPod{
+			Name: podName,
+			UID:  podUID,
+		}
+	}
+	return &k
+}
+
 func cleanTagKey(k string) string {
 	return tagKeyReplacer.Replace(k)
 }