Merge pull request #3836 from chenzhiwei/hostname

Allow customizing pod hostname

cmd/podman/cliconfig/config.go

@@ -300,6 +300,7 @@ type PodCreateValues struct {
 	LabelFile    []string
 	Labels       []string
 	Name         string
+	Hostname     string
 	PodIDFile    string
 	Publish      []string
 	Share        string

cmd/podman/pod_create.go

@@ -52,6 +52,7 @@ func init() {
 	flags.StringSliceVar(&podCreateCommand.LabelFile, "label-file", []string{}, "Read in a line delimited file of labels")
 	flags.StringSliceVarP(&podCreateCommand.Labels, "label", "l", []string{}, "Set metadata on pod (default [])")
 	flags.StringVarP(&podCreateCommand.Name, "name", "n", "", "Assign a name to the pod")
+	flags.StringVarP(&podCreateCommand.Hostname, "hostname", "", "", "Set a hostname to the pod")
 	flags.StringVar(&podCreateCommand.PodIDFile, "pod-id-file", "", "Write the pod ID to the file")
 	flags.StringSliceVarP(&podCreateCommand.Publish, "publish", "p", []string{}, "Publish a container's port, or a range of ports, to the host (default [])")
 	flags.StringVar(&podCreateCommand.Share, "share", shared.DefaultKernelNamespaces, "A comma delimited list of kernel namespaces the pod will share")

libpod/options.go

@@ -1497,6 +1497,24 @@ func WithPodName(name string) PodCreateOption {
 	}
 }
 
+// WithPodHostname sets the hostname of the pod.
+func WithPodHostname(hostname string) PodCreateOption {
+	return func(pod *Pod) error {
+		if pod.valid {
+			return define.ErrPodFinalized
+		}
+
+		// Check the hostname against a regex
+		if !nameRegex.MatchString(hostname) {
+			return regexError
+		}
+
+		pod.config.Hostname = hostname
+
+		return nil
+	}
+}
+
 // WithPodLabels sets the labels of a pod.
 func WithPodLabels(labels map[string]string) PodCreateOption {
 	return func(pod *Pod) error {

libpod/pod.go

@@ -36,6 +36,8 @@ type PodConfig struct {
 	// Namespace the pod is in
 	Namespace string `json:"namespace,omitempty"`
 
+	Hostname string `json:"hostname,omitempty"`
+
 	// Labels contains labels applied to the pod
 	Labels map[string]string `json:"labels"`
 	// CgroupParent contains the pod's CGroup parent

libpod/runtime_pod_infra_linux.go

@@ -31,8 +31,8 @@ func (r *Runtime) makeInfraContainer(ctx context.Context, p *Pod, imgName, imgID
 		return nil, err
 	}
 
-	// Set Pod hostname as Pod name
-	g.Config.Hostname = p.config.Name
+	// Set Pod hostname
+	g.Config.Hostname = p.config.Hostname
 
 	isRootless := rootless.IsRootless()
 

libpod/runtime_pod_linux.go

@@ -52,6 +52,10 @@ func (r *Runtime) NewPod(ctx context.Context, options ...PodCreateOption) (_ *Po
 		pod.config.Name = name
 	}
 
+	if pod.config.Hostname == "" {
+		pod.config.Hostname = pod.config.Name
+	}
+
 	// Allocate a lock for the pod
 	lock, err := r.lockManager.AllocateLock()
 	if err != nil {

pkg/adapter/pods.go

@@ -256,6 +256,10 @@ func (r *LocalRuntime) CreatePod(ctx context.Context, cli *cliconfig.PodCreateVa
 		options = append(options, libpod.WithPodName(cli.Name))
 	}
 
+	if cli.Flag("hostname").Changed {
+		options = append(options, libpod.WithPodHostname(cli.Hostname))
+	}
+
 	if cli.Infra {
 		options = append(options, libpod.WithInfraContainer())
 		nsOptions, err := shared.GetNamespaceOptions(strings.Split(cli.Share, ","))
@@ -476,6 +480,12 @@ func (r *LocalRuntime) PlayKubeYAML(ctx context.Context, c *cliconfig.KubePlayVa
 	podOptions = append(podOptions, libpod.WithPodName(podName))
 	// TODO for now we just used the default kernel namespaces; we need to add/subtract this from yaml
 
+	hostname := podYAML.Spec.Hostname
+	if hostname == "" {
+		hostname = podName
+	}
+	podOptions = append(podOptions, libpod.WithPodHostname(hostname))
+
 	nsOptions, err := shared.GetNamespaceOptions(strings.Split(shared.DefaultKernelNamespaces, ","))
 	if err != nil {
 		return nil, err

test/e2e/play_kube_test.go

@@ -21,6 +21,7 @@ metadata:
     app: {{ .Name }}
   name: {{ .Name }}
 spec:
+  hostname: {{ .Hostname }}
   containers:
 {{ with .Containers }}
   {{ range . }}
@@ -66,6 +67,7 @@ status: {}
 
 type Pod struct {
 	Name       string
+	Hostname   string
 	Containers []Container
 }
 
@@ -78,13 +80,13 @@ type Container struct {
 	CapDrop []string
 }
 
-func generateKubeYaml(ctrs []Container, fileName string) error {
+func generateKubeYaml(name string, hostname string, ctrs []Container, fileName string) error {
 	f, err := os.Create(fileName)
 	if err != nil {
 		return err
 	}
 	defer f.Close()
-	testPod := Pod{"test", ctrs}
+	testPod := Pod{name, hostname, ctrs}
 
 	t, err := template.New("pod").Parse(yamlTemplate)
 	if err != nil {
@@ -127,7 +129,7 @@ var _ = Describe("Podman generate kube", func() {
 		testContainer := Container{ctrCmd, ALPINE, ctrName, false, nil, nil}
 		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
 
-		err := generateKubeYaml([]Container{testContainer}, tempFile)
+		err := generateKubeYaml("test", "", []Container{testContainer}, tempFile)
 		Expect(err).To(BeNil())
 
 		kube := podmanTest.Podman([]string{"play", "kube", tempFile})
@@ -146,7 +148,7 @@ var _ = Describe("Podman generate kube", func() {
 		testContainer := Container{ctrCmd, ALPINE, ctrName, false, nil, nil}
 		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
 
-		err := generateKubeYaml([]Container{testContainer}, tempFile)
+		err := generateKubeYaml("test", "", []Container{testContainer}, tempFile)
 		Expect(err).To(BeNil())
 
 		kube := podmanTest.Podman([]string{"play", "kube", tempFile})
@@ -164,6 +166,46 @@ var _ = Describe("Podman generate kube", func() {
 		Expect(inspect.OutputToString()).To(ContainSubstring("hello"))
 	})
 
+	It("podman play kube test hostname", func() {
+		podName := "test"
+		ctrName := "testCtr"
+		ctrCmd := []string{"top"}
+		testContainer := Container{ctrCmd, ALPINE, ctrName, false, nil, nil}
+		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
+
+		err := generateKubeYaml(podName, "", []Container{testContainer}, tempFile)
+		Expect(err).To(BeNil())
+
+		kube := podmanTest.Podman([]string{"play", "kube", tempFile})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube.ExitCode()).To(Equal(0))
+
+		inspect := podmanTest.Podman([]string{"inspect", ctrName, "--format", "{{ .Config.Hostname }}"})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect.ExitCode()).To(Equal(0))
+		Expect(inspect.OutputToString()).To(Equal(podName))
+	})
+
+	It("podman play kube test with customized hostname", func() {
+		hostname := "myhostname"
+		ctrName := "testCtr"
+		ctrCmd := []string{"top"}
+		testContainer := Container{ctrCmd, ALPINE, ctrName, false, nil, nil}
+		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
+
+		err := generateKubeYaml("test", hostname, []Container{testContainer}, tempFile)
+		Expect(err).To(BeNil())
+
+		kube := podmanTest.Podman([]string{"play", "kube", tempFile})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube.ExitCode()).To(Equal(0))
+
+		inspect := podmanTest.Podman([]string{"inspect", ctrName, "--format", "{{ .Config.Hostname }}"})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect.ExitCode()).To(Equal(0))
+		Expect(inspect.OutputToString()).To(Equal(hostname))
+	})
+
 	It("podman play kube cap add", func() {
 		ctrName := "testCtr"
 		ctrCmd := []string{"cat", "/proc/self/status"}
@@ -171,7 +213,7 @@ var _ = Describe("Podman generate kube", func() {
 		testContainer := Container{ctrCmd, ALPINE, ctrName, true, []string{capAdd}, nil}
 		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
 
-		err := generateKubeYaml([]Container{testContainer}, tempFile)
+		err := generateKubeYaml("test", "", []Container{testContainer}, tempFile)
 		Expect(err).To(BeNil())
 
 		kube := podmanTest.Podman([]string{"play", "kube", tempFile})
@@ -191,7 +233,7 @@ var _ = Describe("Podman generate kube", func() {
 		testContainer := Container{ctrCmd, ALPINE, ctrName, true, []string{capDrop}, nil}
 		tempFile := filepath.Join(podmanTest.TempDir, "kube.yaml")
 
-		err := generateKubeYaml([]Container{testContainer}, tempFile)
+		err := generateKubeYaml("test", "", []Container{testContainer}, tempFile)
 		Expect(err).To(BeNil())
 
 		kube := podmanTest.Podman([]string{"play", "kube", tempFile})