[CI:DOCS] introduce --replace flag for play kube

With this flag, users can easily sync up the yaml content with the existing pods.

Fixes containers#11481

Signed-off-by: Chen Zhiwei <zhiweik@gmail.com>

cmd/podman/play/kube.go

@@ -11,6 +11,7 @@ import (
 	"github.com/containers/podman/v3/cmd/podman/common"
 	"github.com/containers/podman/v3/cmd/podman/registry"
 	"github.com/containers/podman/v3/cmd/podman/utils"
+	"github.com/containers/podman/v3/libpod/define"
 	"github.com/containers/podman/v3/pkg/domain/entities"
 	"github.com/containers/podman/v3/pkg/util"
 	"github.com/pkg/errors"
@@ -89,6 +90,9 @@ func init() {
 	downFlagName := "down"
 	flags.BoolVar(&kubeOptions.Down, downFlagName, false, "Stop pods defined in the YAML file")
 
+	replaceFlagName := "replace"
+	flags.BoolVar(&kubeOptions.Replace, replaceFlagName, false, "Delete and recreate pods defined in the YAML file")
+
 	if !registry.IsRemote() {
 		certDirFlagName := "cert-dir"
 		flags.StringVar(&kubeOptions.CertDir, certDirFlagName, "", "`Pathname` of a directory containing TLS certificates and keys")
@@ -150,6 +154,11 @@ func kube(cmd *cobra.Command, args []string) error {
 	if kubeOptions.Down {
 		return teardown(yamlfile)
 	}
+	if kubeOptions.Replace {
+		if err := teardown(yamlfile); err != nil && !errors.Is(err, define.ErrNoSuchPod) {
+			return err
+		}
+	}
 	return playkube(yamlfile)
 }
 

docs/source/markdown/podman-play-kube.1.md

@@ -9,6 +9,7 @@ podman-play-kube - Create containers, pods or volumes based on Kubernetes YAML
 ## DESCRIPTION
 **podman play kube** will read in a structured file of Kubernetes YAML.  It will then recreate the containers, pods or volumes described in the YAML.  Containers within a pod are then started and the ID of the new Pod or the name of the new Volume is output. If the yaml file is specified as "-" then `podman play kube` will read the YAML file from stdin.
 Using the `--down` command line option, it is also capable of tearing down the pods created by a previous run of `podman play kube`.
+Using the `--replace` command line option, it will tear down the pods(if any) created by a previous run of `podman play kube` and recreate the pods with the Kubernetes YAML file.
 Ideally the input file would be one created by Podman (see podman-generate-kube(1)).  This would guarantee a smooth import and expected results.
 
 Currently, the supported Kubernetes kinds are:
@@ -142,6 +143,10 @@ Valid _mode_ values are:
 
 Suppress output information when pulling images
 
+#### **--replace**
+
+Tears down the pods that were created by a previous run of `play kube` and recreate pods, this is used to keep the existing pods and Kubernetes YAML file up to date.
+
 #### **--seccomp-profile-root**=*path*
 
 Directory path for seccomp profiles (default: "/var/lib/kubelet/seccomp"). (This option is not available with the remote Podman client)

pkg/domain/entities/play.go

@@ -17,6 +17,8 @@ type PlayKubeOptions struct {
 	// Down indicates whether to bring contents of a yaml file "down"
 	// as in stop
 	Down bool
+	// Replace indicates whether to delete and recreate a yaml file
+	Replace bool
 	// Username for authenticating against the registry.
 	Username string
 	// Password for authenticating against the registry.

test/e2e/play_kube_test.go

@@ -2722,4 +2722,58 @@ invalid kube kind
 		exists.WaitWithDefaultTimeout()
 		Expect(exists).To(Exit(0))
 	})
+
+	It("podman play kube replace", func() {
+		pod := getPod()
+		err := generateKubeYaml("pod", pod, kubeYaml)
+		Expect(err).To(BeNil())
+
+		kube := podmanTest.Podman([]string{"play", "kube", kubeYaml})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube).Should(Exit(0))
+
+		ls := podmanTest.Podman([]string{"pod", "ps", "--format", "'{{.ID}}'"})
+		ls.WaitWithDefaultTimeout()
+		Expect(ls).Should(Exit(0))
+		Expect(len(ls.OutputToStringArray())).To(Equal(1))
+
+		containerLen := podmanTest.Podman([]string{"pod", "inspect", pod.Name, "--format", "'{{len .Containers}}'"})
+
+		ctr01Name := "ctr01"
+		ctr02Name := "ctr02"
+
+		ctr01 := getCtr(withName(ctr01Name))
+		ctr02 := getCtr(withName(ctr02Name))
+
+		newPod := getPod(
+			withCtr(ctr01),
+			withCtr(ctr02),
+		)
+		err = generateKubeYaml("pod", newPod, kubeYaml)
+		Expect(err).To(BeNil())
+
+		replace := podmanTest.Podman([]string{"play", "kube", "--replace", kubeYaml})
+		replace.WaitWithDefaultTimeout()
+		Expect(replace).Should(Exit(0))
+
+		newContainerLen := podmanTest.Podman([]string{"pod", "inspect", newPod.Name, "--format", "'{{len .Containers}}'"})
+		newContainerLen.WaitWithDefaultTimeout()
+		Expect(newContainerLen).Should(Exit(0))
+		Expect(newContainerLen.OutputToString()).NotTo(Equal(containerLen.OutputToString()))
+	})
+
+	It("podman play kube replace non-existing pod", func() {
+		pod := getPod()
+		err := generateKubeYaml("pod", pod, kubeYaml)
+		Expect(err).To(BeNil())
+
+		replace := podmanTest.Podman([]string{"play", "kube", "--replace", kubeYaml})
+		replace.WaitWithDefaultTimeout()
+		Expect(replace).Should(Exit(0))
+
+		ls := podmanTest.Podman([]string{"pod", "ps", "--format", "'{{.ID}}'"})
+		ls.WaitWithDefaultTimeout()
+		Expect(ls).Should(Exit(0))
+		Expect(len(ls.OutputToStringArray())).To(Equal(1))
+	})
 })