Don't emit Kubernetes autodiscover events without host

CHANGELOG.asciidoc

@@ -66,6 +66,7 @@ https://github.com/elastic/beats/compare/v6.2.3...master[Check the HEAD diff]
 - Negotiate Docker API version from our client instead of using a hardcoded one. {pull}7165[7165]
 - Fix delays on autodiscovery events handling caused by blocking runner stops. {pull}7170[7170]
 - Error out on invalid Autodiscover template conditions settings. {pull}7200[7200]
+- Do not emit Kubernetes autodiscover events for Pods without IP address. {pull}7235[7235]
 
 *Auditbeat*
 

libbeat/autodiscover/providers/kubernetes/kubernetes.go

@@ -87,13 +87,16 @@ func AutodiscoverBuilder(bus bus.Bus, c *common.Config) (autodiscover.Provider,
 
 	watcher.AddEventHandler(kubernetes.ResourceEventHandlerFuncs{
 		AddFunc: func(obj kubernetes.Resource) {
+			logp.Debug("kubernetes", "Watcher Pod add: %+v", obj)
 			p.emit(obj.(*kubernetes.Pod), "start")
 		},
 		UpdateFunc: func(obj kubernetes.Resource) {
+			logp.Debug("kubernetes", "Watcher Pod update: %+v", obj)
 			p.emit(obj.(*kubernetes.Pod), "stop")
 			p.emit(obj.(*kubernetes.Pod), "start")
 		},
 		DeleteFunc: func(obj kubernetes.Resource) {
+			logp.Debug("kubernetes", "Watcher Pod delete: %+v", obj)
 			time.AfterFunc(config.CleanupTimeout, func() { p.emit(obj.(*kubernetes.Pod), "stop") })
 		},
 	})
@@ -120,6 +123,11 @@ func (p *Provider) emitEvents(pod *kubernetes.Pod, flag string, containers []kub
 	containerstatuses []kubernetes.PodContainerStatus) {
 	host := pod.Status.PodIP
 
+	// Do not emit events without host (container is still being configured)
+	if host == "" {
+		return
+	}
+
 	// Collect all container IDs and runtimes from status information.
 	containerIDs := map[string]string{}
 	runtimes := map[string]string{}

libbeat/autodiscover/providers/kubernetes/kubernetes_test.go

@@ -2,11 +2,14 @@ package kubernetes
 
 import (
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 
+	"github.com/elastic/beats/libbeat/autodiscover/template"
 	"github.com/elastic/beats/libbeat/common"
 	"github.com/elastic/beats/libbeat/common/bus"
+	"github.com/elastic/beats/libbeat/common/kubernetes"
 )
 
 func TestGenerateHints(t *testing.T) {
@@ -129,6 +132,140 @@ func TestGenerateHints(t *testing.T) {
 	}
 }
 
+func TestEmitEvent(t *testing.T) {
+	tests := []struct {
+		Message  string
+		Flag     string
+		Pod      *kubernetes.Pod
+		Expected bus.Event
+	}{
+		{
+			Message: "Test common pod start",
+			Flag:    "start",
+			Pod: &kubernetes.Pod{
+				Metadata: kubernetes.ObjectMeta{
+					Name:        "filebeat",
+					Namespace:   "default",
+					Labels:      map[string]string{},
+					Annotations: map[string]string{},
+				},
+				Status: kubernetes.PodStatus{
+					PodIP: "127.0.0.1",
+					ContainerStatuses: []kubernetes.PodContainerStatus{
+						{
+							Name:        "filebeat",
+							ContainerID: "docker://foobar",
+						},
+					},
+				},
+				Spec: kubernetes.PodSpec{
+					NodeName: "node",
+					Containers: []kubernetes.Container{
+						{
+							Image: "elastic/filebeat:6.3.0",
+							Name:  "filebeat",
+						},
+					},
+				},
+			},
+			Expected: bus.Event{
+				"start": true,
+				"host":  "127.0.0.1",
+				"kubernetes": common.MapStr{
+					"container": common.MapStr{
+						"id":      "foobar",
+						"name":    "filebeat",
+						"image":   "elastic/filebeat:6.3.0",
+						"runtime": "docker",
+					},
+					"pod": common.MapStr{
+						"name": "filebeat",
+					},
+					"node": common.MapStr{
+						"name": "node",
+					},
+					"namespace":   "default",
+					"annotations": common.MapStr{},
+				},
+				"meta": common.MapStr{
+					"kubernetes": common.MapStr{
+						"namespace": "default",
+						"container": common.MapStr{
+							"name": "filebeat",
+						}, "pod": common.MapStr{
+							"name": "filebeat",
+						}, "node": common.MapStr{
+							"name": "node",
+						},
+					},
+				},
+			},
+		},
+		{
+			Message: "Test pod without host",
+			Flag:    "start",
+			Pod: &kubernetes.Pod{
+				Metadata: kubernetes.ObjectMeta{
+					Name:        "filebeat",
+					Namespace:   "default",
+					Labels:      map[string]string{},
+					Annotations: map[string]string{},
+				},
+				Status: kubernetes.PodStatus{
+					ContainerStatuses: []kubernetes.PodContainerStatus{
+						{
+							Name:        "filebeat",
+							ContainerID: "docker://foobar",
+						},
+					},
+				},
+				Spec: kubernetes.PodSpec{
+					NodeName: "node",
+					Containers: []kubernetes.Container{
+						{
+							Image: "elastic/filebeat:6.3.0",
+							Name:  "filebeat",
+						},
+					},
+				},
+			},
+			Expected: nil,
+		},
+	}
+
+	for _, test := range tests {
+		mapper, err := template.NewConfigMapper(nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		metaGen, err := kubernetes.NewMetaGenerator(common.NewConfig())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		p := &Provider{
+			config:    defaultConfig(),
+			bus:       bus.New("test"),
+			metagen:   metaGen,
+			templates: mapper,
+		}
+
+		listener := p.bus.Subscribe()
+
+		p.emit(test.Pod, test.Flag)
+
+		select {
+		case event := <-listener.Events():
+			assert.Equal(t, test.Expected, event)
+		case <-time.After(2 * time.Second):
+			if test.Expected != nil {
+				t.Fatal("Timeout while waiting for event")
+			}
+		}
+	}
+}
+
 func getNestedAnnotations(in common.MapStr) common.MapStr {
 	out := common.MapStr{}