Merge pull request #14181 from umohnani8/kube-hostname

Add ports and hostname correctly in kube yaml

Author: openshift-ci[bot]

libpod/kube.go

@@ -353,6 +353,7 @@ func (p *Pod) podWithContainers(ctx context.Context, containers []*Container, po
 	podInitCtrs := []v1.Container{}
 	podAnnotations := make(map[string]string)
 	dnsInfo := v1.PodDNSConfig{}
+	var hostname string
 
 	// Let's sort the containers in order of created time
 	// This will ensure that the init containers are defined in the correct order in the kube yaml
@@ -368,6 +369,14 @@ func (p *Pod) podWithContainers(ctx context.Context, containers []*Container, po
 				podAnnotations[k] = TruncateKubeAnnotation(v)
 			}
 			isInit := ctr.IsInitCtr()
+			// Since hostname is only set at pod level, set the hostname to the hostname of the first container we encounter
+			if hostname == "" {
+				// Only set the hostname if it is not set to the truncated container ID, which we do by default if no
+				// hostname is specified for the container
+				if !strings.Contains(ctr.ID(), ctr.Hostname()) {
+					hostname = ctr.Hostname()
+				}
+			}
 
 			ctr, volumes, _, annotations, err := containerToV1Container(ctx, ctr)
 			if err != nil {
@@ -377,17 +386,21 @@ func (p *Pod) podWithContainers(ctx context.Context, containers []*Container, po
 				podAnnotations[define.BindMountPrefix+k] = TruncateKubeAnnotation(v)
 			}
 			// Since port bindings for the pod are handled by the
-			// infra container, wipe them here.
-			ctr.Ports = nil
-
-			// We add the original port declarations from the libpod infra container
-			// to the first kubernetes container description because otherwise we loose
-			// the original container/port bindings.
-			// Add the port configuration to the first regular container or the first
-			// init container if only init containers have been created in the pod.
-			if first && len(ports) > 0 && (!isInit || len(containers) == 2) {
-				ctr.Ports = ports
-				first = false
+			// infra container, wipe them here only if we are sharing the net namespace
+			// If the network namespace is not being shared in the pod, then containers
+			// can have their own network configurations
+			if p.SharesNet() {
+				ctr.Ports = nil
+
+				// We add the original port declarations from the libpod infra container
+				// to the first kubernetes container description because otherwise we loose
+				// the original container/port bindings.
+				// Add the port configuration to the first regular container or the first
+				// init container if only init containers have been created in the pod.
+				if first && len(ports) > 0 && (!isInit || len(containers) == 2) {
+					ctr.Ports = ports
+					first = false
+				}
 			}
 			if isInit {
 				podInitCtrs = append(podInitCtrs, ctr)
@@ -430,10 +443,11 @@ func (p *Pod) podWithContainers(ctx context.Context, containers []*Container, po
 		podContainers,
 		podVolumes,
 		&dnsInfo,
-		hostNetwork), nil
+		hostNetwork,
+		hostname), nil
 }
 
-func newPodObject(podName string, annotations map[string]string, initCtrs, containers []v1.Container, volumes []v1.Volume, dnsOptions *v1.PodDNSConfig, hostNetwork bool) *v1.Pod {
+func newPodObject(podName string, annotations map[string]string, initCtrs, containers []v1.Container, volumes []v1.Volume, dnsOptions *v1.PodDNSConfig, hostNetwork bool, hostname string) *v1.Pod {
 	tm := v12.TypeMeta{
 		Kind:       "Pod",
 		APIVersion: "v1",
@@ -454,6 +468,7 @@ func newPodObject(podName string, annotations map[string]string, initCtrs, conta
 	}
 	ps := v1.PodSpec{
 		Containers:     containers,
+		Hostname:       hostname,
 		HostNetwork:    hostNetwork,
 		InitContainers: initCtrs,
 		Volumes:        volumes,
@@ -479,6 +494,7 @@ func simplePodWithV1Containers(ctx context.Context, ctrs []*Container) (*v1.Pod,
 	podDNS := v1.PodDNSConfig{}
 	kubeAnnotations := make(map[string]string)
 	ctrNames := make([]string, 0, len(ctrs))
+	var hostname string
 	for _, ctr := range ctrs {
 		ctrNames = append(ctrNames, removeUnderscores(ctr.Name()))
 		for k, v := range ctr.config.Spec.Annotations {
@@ -491,6 +507,14 @@ func simplePodWithV1Containers(ctx context.Context, ctrs []*Container) (*v1.Pod,
 		}
 
 		isInit := ctr.IsInitCtr()
+		// Since hostname is only set at pod level, set the hostname to the hostname of the first container we encounter
+		if hostname == "" {
+			// Only set the hostname if it is not set to the truncated container ID, which we do by default if no
+			// hostname is specified for the container
+			if !strings.Contains(ctr.ID(), ctr.Hostname()) {
+				hostname = ctr.Hostname()
+			}
+		}
 
 		if !ctr.HostNetwork() {
 			hostNetwork = false
@@ -555,7 +579,8 @@ func simplePodWithV1Containers(ctx context.Context, ctrs []*Container) (*v1.Pod,
 		kubeCtrs,
 		kubeVolumes,
 		&podDNS,
-		hostNetwork), nil
+		hostNetwork,
+		hostname), nil
 }
 
 // containerToV1Container converts information we know about a libpod container

pkg/domain/infra/abi/generate.go

@@ -50,6 +50,7 @@ func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrIDs []string,
 		content    [][]byte
 	)
 
+	defaultKubeNS := true
 	// Lookup for podman objects.
 	for _, nameOrID := range nameOrIDs {
 		// Let's assume it's a container, so get the container.
@@ -75,6 +76,17 @@ func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrIDs []string,
 				return nil, err
 			}
 		} else {
+			// Get the pod config to see if the user has modified the default
+			// namespace sharing values as this might affect the pods when run
+			// in a k8s cluster
+			podConfig, err := pod.Config()
+			if err != nil {
+				return nil, err
+			}
+			if !(podConfig.UsePodIPC && podConfig.UsePodNet && podConfig.UsePodUTS) {
+				defaultKubeNS = false
+			}
+
 			pods = append(pods, pod)
 			continue
 		}
@@ -94,6 +106,15 @@ func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrIDs []string,
 		return nil, fmt.Errorf("name or ID %q not found", nameOrID)
 	}
 
+	if !defaultKubeNS {
+		warning := `
+# NOTE: The namespace sharing for a pod has been modified by the user and is not the same as the
+# default settings for kubernetes. This can lead to unexpected behavior when running the generated
+# kube yaml in a kubernetes cluster.
+`
+		content = append(content, []byte(warning))
+	}
+
 	// Generate kube persistent volume claims from volumes.
 	if len(vols) >= 1 {
 		pvs, err := getKubePVCs(vols)

test/e2e/generate_kube_test.go

@@ -328,6 +328,109 @@ var _ = Describe("Podman generate kube", func() {
 		Expect(pod.Spec.HostAliases[1]).To(HaveField("IP", testIP))
 	})
 
+	It("podman generate kube with network sharing", func() {
+		// Expect error with default sharing options as Net namespace is shared
+		podName := "testPod"
+		podSession := podmanTest.Podman([]string{"pod", "create", "--name", podName})
+		podSession.WaitWithDefaultTimeout()
+		Expect(podSession).Should(Exit(0))
+
+		ctrSession := podmanTest.Podman([]string{"create", "--name", "testCtr", "--pod", podName, "-p", "9000:8000", ALPINE, "top"})
+		ctrSession.WaitWithDefaultTimeout()
+		Expect(ctrSession).Should(Exit(125))
+
+		// Ports without Net sharing should work with ports being set for each container in the generated kube yaml
+		podName = "testNet"
+		podSession = podmanTest.Podman([]string{"pod", "create", "--name", podName, "--share", "ipc"})
+		podSession.WaitWithDefaultTimeout()
+		Expect(podSession).Should(Exit(0))
+
+		ctr1Name := "ctr1"
+		ctr1Session := podmanTest.Podman([]string{"create", "--name", ctr1Name, "--pod", podName, "-p", "9000:8000", ALPINE, "top"})
+		ctr1Session.WaitWithDefaultTimeout()
+		Expect(ctr1Session).Should(Exit(0))
+
+		ctr2Name := "ctr2"
+		ctr2Session := podmanTest.Podman([]string{"create", "--name", ctr2Name, "--pod", podName, "-p", "6000:5000", ALPINE, "top"})
+		ctr2Session.WaitWithDefaultTimeout()
+		Expect(ctr2Session).Should(Exit(0))
+
+		kube := podmanTest.Podman([]string{"generate", "kube", podName})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube).Should(Exit(0))
+
+		pod := new(v1.Pod)
+		err := yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+		Expect(pod.Spec.Containers).To(HaveLen(2))
+		Expect(pod.Spec.Containers[0].Ports[0].ContainerPort).To(Equal(int32(8000)))
+		Expect(pod.Spec.Containers[1].Ports[0].ContainerPort).To(Equal(int32(5000)))
+		Expect(pod.Spec.Containers[0].Ports[0].HostPort).To(Equal(int32(9000)))
+		Expect(pod.Spec.Containers[1].Ports[0].HostPort).To(Equal(int32(6000)))
+	})
+
+	It("podman generate kube with and without hostname", func() {
+		// Expect error with default sharing options as UTS namespace is shared
+		podName := "testPod"
+		podSession := podmanTest.Podman([]string{"pod", "create", "--name", podName})
+		podSession.WaitWithDefaultTimeout()
+		Expect(podSession).Should(Exit(0))
+
+		ctrSession := podmanTest.Podman([]string{"create", "--name", "testCtr", "--pod", podName, "--hostname", "test-hostname", ALPINE, "top"})
+		ctrSession.WaitWithDefaultTimeout()
+		Expect(ctrSession).Should(Exit(125))
+
+		// Hostname without uts sharing should work, but generated kube yaml will have pod hostname
+		// set to the hostname of the first container
+		podName = "testHostname"
+		podSession = podmanTest.Podman([]string{"pod", "create", "--name", podName, "--share", "ipc"})
+		podSession.WaitWithDefaultTimeout()
+		Expect(podSession).Should(Exit(0))
+
+		ctr1Name := "ctr1"
+		ctr1HostName := "ctr1-hostname"
+		ctr1Session := podmanTest.Podman([]string{"create", "--name", ctr1Name, "--pod", podName, "--hostname", ctr1HostName, ALPINE, "top"})
+		ctr1Session.WaitWithDefaultTimeout()
+		Expect(ctr1Session).Should(Exit(0))
+
+		ctr2Name := "ctr2"
+		ctr2Session := podmanTest.Podman([]string{"create", "--name", ctr2Name, "--pod", podName, ALPINE, "top"})
+		ctr2Session.WaitWithDefaultTimeout()
+		Expect(ctr2Session).Should(Exit(0))
+
+		kube := podmanTest.Podman([]string{"generate", "kube", podName})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube).Should(Exit(0))
+
+		pod := new(v1.Pod)
+		err := yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+		Expect(pod.Spec.Containers).To(HaveLen(2))
+		Expect(pod.Spec.Hostname).To(Equal(ctr1HostName))
+
+		// No hostname
+
+		podName = "testNoHostname"
+		podSession = podmanTest.Podman([]string{"pod", "create", "--name", podName, "--share", "ipc"})
+		podSession.WaitWithDefaultTimeout()
+		Expect(podSession).Should(Exit(0))
+
+		ctr3Name := "ctr3"
+		ctr3Session := podmanTest.Podman([]string{"create", "--name", ctr3Name, "--pod", podName, ALPINE, "top"})
+		ctr3Session.WaitWithDefaultTimeout()
+		Expect(ctr3Session).Should(Exit(0))
+
+		kube = podmanTest.Podman([]string{"generate", "kube", podName})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube).Should(Exit(0))
+
+		pod = new(v1.Pod)
+		err = yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+		Expect(pod.Spec.Containers).To(HaveLen(1))
+		Expect(pod.Spec.Hostname).To(BeEmpty())
+	})
+
 	It("podman generate service kube on pod", func() {
 		session := podmanTest.Podman([]string{"create", "--pod", "new:test-pod", "-p", "4000:4000/udp", ALPINE, "ls"})
 		session.WaitWithDefaultTimeout()