@@ -31,7 +31,12 @@ func (cb *CommandBuilder) launch() error {
 		return errors.Wrap(err, "Failed to get info about target pod")
 	}
 
-	targetContainer, err := targetPod.FindContainerInfo(cb.CommonOptions.Container)
+	targetContainerName := cb.CommonOptions.Container
+	if targetContainerName == "" {
+		targetContainerName = targetPod.Annotations["kubectl.kubernetes.io/default-container"]
+	}
+
+	targetContainer, err := targetPod.FindContainerInfo(targetContainerName)
 	if err != nil {
 		return errors.Wrap(err, "Failed to get info about target container")
 	}
@@ -40,7 +45,7 @@ func (cb *CommandBuilder) launch() error {
 		NewJobRunSpec(cb.args(targetContainer), cb.CommonOptions.Image, targetPod).
 		WithContainerFSVolume(targetContainer)
 
-	if targetPod.ContainsMountedTmp(cb.CommonOptions.Container) {
+	if targetPod.ContainsMountedTmp(targetContainerName) {
 		jobSpec.WithContainerMountsVolume(targetContainer)
 	}
 
 
@@ -11,8 +11,8 @@ import (
 
 // ContainerInfo is information about container struct
 type ContainerInfo struct {
-	Runtime string
 	ID      string
+	Runtime string
 }
 
 type containerConfig struct {
@@ -30,8 +30,8 @@ func NewContainerInfo(cs *core.ContainerStatus) *ContainerInfo {
 	containerInfo := strings.Split(cs.ContainerID, "://")
 
 	return &ContainerInfo{
-		Runtime: containerInfo[0],
 		ID:      containerInfo[1],
+		Runtime: containerInfo[0],
 	}
 }
 
 
@@ -15,6 +15,7 @@ import (
 )
 
 type PodInfo struct {
+	Annotations       map[string]string
 	Name              string
 	Node              string
 	containers        []core.Container
@@ -24,6 +25,7 @@ type PodInfo struct {
 // NewPodInfo returns PodInfo generated from core.Pod spec
 func NewPodInfo(pod *core.Pod) *PodInfo {
 	return &PodInfo{
+		Annotations:       pod.Annotations,
 		Name:              pod.Name,
 		Node:              pod.Spec.NodeName,
 		containers:        pod.Spec.Containers,
 
@@ -41,6 +41,11 @@ func Test_DumpSubcommand(t *testing.T) {
 			},
 			pod: multiContainerPod(),
 		},
+		{
+			name: "MultiContainer pod with default-container annotation",
+			args: []string{},
+			pod:  multiContainerPodWithDefaultContainer(),
+		},
 		{
 			name: "MultiContainer pod with shared mount",
 			args: []string{
 
@@ -50,6 +50,11 @@ func Test_GCDumpSubcommand(t *testing.T) {
 			},
 			pod: multiContainerPod(),
 		},
+		{
+			name: "MultiContainer pod with default-container annotation",
+			args: []string{},
+			pod:  multiContainerPodWithDefaultContainer(),
+		},
 		{
 			name: "MultiContainer pod with shared mount",
 			args: []string{
 
@@ -51,13 +51,18 @@ func Test_TraceSubcommand(t *testing.T) {
 			pod: singleContainerPod(),
 		},
 		{
-			name: "Multicontainer pod",
+			name: "MultiContainer pod",
 			args: []string{
 				"--container",
 				targetContainerName,
 			},
 			pod: multiContainerPod(),
 		},
+		{
+			name: "MultiContainer pod with default-container annotation",
+			args: []string{},
+			pod:  multiContainerPodWithDefaultContainer(),
+		},
 		{
 			name: "MultiContainer pod with shared mount",
 			args: []string{
 
@@ -118,6 +118,28 @@ func multiContainerPod() *core.Pod {
 	}
 }
 
+func multiContainerPodWithDefaultContainer() *core.Pod {
+	objectMeta := generateRandomPodMeta()
+	objectMeta.Annotations = map[string]string{
+		"kubectl.kubernetes.io/default-container": targetContainerName,
+	}
+	return &core.Pod{
+		ObjectMeta: objectMeta,
+		Spec: core.PodSpec{
+			Containers: []core.Container{
+				{
+					Name:  targetContainerName,
+					Image: sampleAppImage,
+				},
+				{
+					Name:  "sidecar",
+					Image: "gcr.io/google_containers/pause-amd64:3.1",
+				},
+			},
+		},
+	}
+}
+
 func multiContainerPodWithSharedMount() *core.Pod {
 	return &core.Pod{
 		ObjectMeta: generateRandomPodMeta(),
Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,12 @@ func (cb *CommandBuilder) launch() error {`
`31`	`31`	`return errors.Wrap(err, "Failed to get info about target pod")`
`32`	`32`	`}`
`33`	`33`
`34`		`- targetContainer, err := targetPod.FindContainerInfo(cb.CommonOptions.Container)`
	`34`	`+ targetContainerName := cb.CommonOptions.Container`
	`35`	`+ if targetContainerName == "" {`
	`36`	`+ targetContainerName = targetPod.Annotations["kubectl.kubernetes.io/default-container"]`
	`37`	`+ }`
	`38`	`+`
	`39`	`+ targetContainer, err := targetPod.FindContainerInfo(targetContainerName)`
`35`	`40`	`if err != nil {`
`36`	`41`	`return errors.Wrap(err, "Failed to get info about target container")`
`37`	`42`	`}`
`@@ -40,7 +45,7 @@ func (cb *CommandBuilder) launch() error {`
`40`	`45`	`NewJobRunSpec(cb.args(targetContainer), cb.CommonOptions.Image, targetPod).`
`41`	`46`	`WithContainerFSVolume(targetContainer)`
`42`	`47`
`43`		`- if targetPod.ContainsMountedTmp(cb.CommonOptions.Container) {`
	`48`	`+ if targetPod.ContainsMountedTmp(targetContainerName) {`
`44`	`49`	`jobSpec.WithContainerMountsVolume(targetContainer)`
`45`	`50`	`}`
`46`	`51`
Original file line number	Diff line number	Diff line change
`@@ -11,8 +11,8 @@ import (`
`11`	`11`
`12`	`12`	`// ContainerInfo is information about container struct`
`13`	`13`	`type ContainerInfo struct {`
`14`		`- Runtime string`
`15`	`14`	`ID string`
	`15`	`+ Runtime string`
`16`	`16`	`}`
`17`	`17`
`18`	`18`	`type containerConfig struct {`
`@@ -30,8 +30,8 @@ func NewContainerInfo(cs core.ContainerStatus) ContainerInfo {`
`30`	`30`	`containerInfo := strings.Split(cs.ContainerID, "://")`
`31`	`31`
`32`	`32`	`return &ContainerInfo{`
`33`		`- Runtime: containerInfo[0],`
`34`	`33`	`ID: containerInfo[1],`
	`34`	`+ Runtime: containerInfo[0],`
`35`	`35`	`}`
`36`	`36`	`}`
`37`	`37`