add "podman kube down" command

The "podman kube down" reads in a structured file of
Kubernetes YAML and removes pods based on the Kubernetes kind described in the YAML,
similiar to "podman play kube --down". Users will still be able to use
"podman play kube --down" and "podman kube play --down" to
perform the same function.

Signed-off-by: Niall Crowe <nicrowe@redhat.com>

6 files changed, 145 insertions, 38 deletions

diff --git a/cmd/podman/kube/down.go b/cmd/podman/kube/down.go
new file mode 100644
index 000000000..b8c025928
--- /dev/null
+++ b/cmd/podman/kube/down.go
@@ -0,0 +1,39 @@
+package pods
+
+import (
+	"github.com/containers/podman/v4/cmd/podman/common"
+	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/spf13/cobra"
+)
+
+var (
+	downDescription = `Reads in a structured file of Kubernetes YAML.
+
+  Removes pods that have been based on the Kubernetes kind described in the YAML.`
+
+	downCmd = &cobra.Command{
+		Use:               "down KUBEFILE|-",
+		Short:             "Remove pods based on Kubernetes YAML.",
+		Long:              downDescription,
+		RunE:              down,
+		Args:              cobra.ExactArgs(1),
+		ValidArgsFunction: common.AutocompleteDefaultOneArg,
+		Example: `podman kube down nginx.yml
+   cat nginx.yml | podman kube down -`,
+	}
+)
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Command: downCmd,
+		Parent:  kubeCmd,
+	})
+}
+
+func down(cmd *cobra.Command, args []string) error {
+	reader, err := readerFromArg(args[0])
+	if err != nil {
+		return err
+	}
+	return teardown(reader)
+}
diff --git a/cmd/podman/kube/play.go b/cmd/podman/kube/play.go
index 6e0050cbf..4811bcf4b 100644
--- a/cmd/podman/kube/play.go
+++ b/cmd/podman/kube/play.go
@@ -1,8 +1,10 @@
 package pods
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"os"
 	"strings"
@@ -37,9 +39,9 @@ var (
 	// https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/
 	defaultSeccompRoot = "/var/lib/kubelet/seccomp"
 	playOptions        = playKubeOptionsWrapper{}
-	playDescription    = `Command reads in a structured file of Kubernetes YAML.
+	playDescription    = `Reads in a structured file of Kubernetes YAML.
 
-  It creates pods or volumes based on the Kubernetes kind described in the YAML. Supported kinds are Pods, Deployments and PersistentVolumeClaims.`
+  Creates pods or volumes based on the Kubernetes kind described in the YAML. Supported kinds are Pods, Deployments and PersistentVolumeClaims.`
 
 	playCmd = &cobra.Command{
 		Use:               "play [options] KUBEFILE|-",
@@ -139,6 +141,7 @@ func playFlags(cmd *cobra.Command) {
 
 	downFlagName := "down"
 	flags.BoolVar(&playOptions.Down, downFlagName, false, "Stop pods defined in the YAML file")
+	_ = flags.MarkHidden("down")
 
 	replaceFlagName := "replace"
 	flags.BoolVar(&playOptions.Replace, replaceFlagName, false, "Delete and recreate pods defined in the YAML file")
@@ -164,7 +167,7 @@ func playFlags(cmd *cobra.Command) {
 		_ = cmd.RegisterFlagCompletionFunc(contextDirFlagName, completion.AutocompleteDefault)
 
 		// NOTE: The service-container flag is marked as hidden as it
-		// is purely designed for running kube-play or play-kube in systemd units.
+		// is purely designed for running kube-play in systemd units.
 		// It is not something users should need to know or care about.
 		//
 		// Having a flag rather than an env variable is cleaner.
@@ -223,10 +226,6 @@ func Play(cmd *cobra.Command, args []string) error {
 		}
 		playOptions.Annotations[splitN[0]] = annotation
 	}
-	yamlfile := args[0]
-	if yamlfile == "-" {
-		yamlfile = "/dev/stdin"
-	}
 
 	for _, mac := range playOptions.macs {
 		m, err := net.ParseMAC(mac)
@@ -235,36 +234,62 @@ func Play(cmd *cobra.Command, args []string) error {
 		}
 		playOptions.StaticMACs = append(playOptions.StaticMACs, m)
 	}
+
+	reader, err := readerFromArg(args[0])
+	if err != nil {
+		return err
+	}
+
 	if playOptions.Down {
-		return teardown(yamlfile)
+		return teardown(reader)
 	}
+
 	if playOptions.Replace {
-		if err := teardown(yamlfile); err != nil && !errorhandling.Contains(err, define.ErrNoSuchPod) {
+		if err := teardown(reader); err != nil && !errorhandling.Contains(err, define.ErrNoSuchPod) {
+			return err
+		}
+		if _, err := reader.Seek(0, 0); err != nil {
 			return err
 		}
 	}
-	return kubeplay(yamlfile)
+	return kubeplay(reader)
 }
 
 func playKube(cmd *cobra.Command, args []string) error {
 	return Play(cmd, args)
 }
 
-func teardown(yamlfile string) error {
+func readerFromArg(fileName string) (*bytes.Reader, error) {
+	if fileName == "-" { // Read from stdin
+		data, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			return nil, err
+		}
+		return bytes.NewReader(data), nil
+	}
+	f, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	data, err := io.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+	return bytes.NewReader(data), nil
+}
+
+func teardown(body io.Reader) error {
 	var (
 		podStopErrors utils.OutputErrors
 		podRmErrors   utils.OutputErrors
 	)
 	options := new(entities.PlayKubeDownOptions)
-	f, err := os.Open(yamlfile)
+	reports, err := registry.ContainerEngine().PlayKubeDown(registry.GetContext(), body, *options)
 	if err != nil {
 		return err
 	}
-	defer f.Close()
-	reports, err := registry.ContainerEngine().PlayKubeDown(registry.GetContext(), f, *options)
-	if err != nil {
-		return fmt.Errorf("%v: %w", yamlfile, err)
-	}
 
 	// Output stopped pods
 	fmt.Println("Pods stopped:")
@@ -290,19 +315,15 @@ func teardown(yamlfile string) error {
 			podRmErrors = append(podRmErrors, removed.Err)
 		}
 	}
+
 	return podRmErrors.PrintErrors()
 }
 
-func kubeplay(yamlfile string) error {
-	f, err := os.Open(yamlfile)
+func kubeplay(body io.Reader) error {
+	report, err := registry.ContainerEngine().PlayKube(registry.GetContext(), body, playOptions.PlayKubeOptions)
 	if err != nil {
 		return err
 	}
-	defer f.Close()
-	report, err := registry.ContainerEngine().PlayKube(registry.GetContext(), f, playOptions.PlayKubeOptions)
-	if err != nil {
-		return fmt.Errorf("%s: %w", yamlfile, err)
-	}
 	// Print volumes report
 	for i, volume := range report.Volumes {
 		if i == 0 {
diff --git a/docs/source/markdown/podman-kube-down.1.md b/docs/source/markdown/podman-kube-down.1.md
new file mode 100644
index 000000000..35725043b
--- /dev/null
+++ b/docs/source/markdown/podman-kube-down.1.md
@@ -0,0 +1,43 @@
+% podman-kube-down(1)
+
+## NAME
+podman-kube-down - Remove containers and pods based on Kubernetes YAML
+
+## SYNOPSIS
+**podman kube down** *file.yml|-*
+
+## DESCRIPTION
+**podman kube down** reads a specified Kubernetes YAML file, tearing down pods that were created by the `podman kube play` command via the same Kubernetes YAML file. Any volumes that were created by the previous `podman kube play` command remain intact. If the YAML file is specified as `-`, `podman kube down` reads the YAML from stdin.
+
+## EXAMPLES
+
+Example YAML file `demo.yml`:
+```
+apiVersion: v1
+kind: Pod
+metadata:
+...
+spec:
+  containers:
+  - command:
+    - top
+    - name: container
+      value: podman
+    image: foobar
+...
+```
+
+Remove the pod and containers as described in the `demo.yml` file
+```
+$ podman kube down demo.yml
+52182811df2b1e73f36476003a66ec872101ea59034ac0d4d3a7b40903b955a6
+```
+
+Remove the pod and containers as described in the`demo.yml` file YAML sent to stdin
+```
+$ cat demo.yml | podman kube play -
+52182811df2b1e73f36476003a66ec872101ea59034ac0d4d3a7b40903b955a6
+```
+
+## SEE ALSO
+**[podman(1)](podman.1.md)**, **[podman-kube(1)](podman-kube.1.md)**, **[podman-kube-play(1)](podman-kube-play.1.md)**, **[podman-generate-kube(1)](podman-generate-kube.1.md)**, **[containers-certs.d(5)](https://github.com/containers/image/blob/main/docs/containers-certs.d.5.md)**
diff --git a/docs/source/markdown/podman-kube-play.1.md b/docs/source/markdown/podman-kube-play.1.md
index 25248ce99..b3c385fe9 100644
--- a/docs/source/markdown/podman-kube-play.1.md
+++ b/docs/source/markdown/podman-kube-play.1.md
@@ -1,7 +1,7 @@
 % podman-kube-play(1)
 
 ## NAME
-podman-kube-play - Create containers, pods or volumes based on Kubernetes YAML
+podman-kube-play - Create containers, pods and volumes based on Kubernetes YAML
 
 ## SYNOPSIS
 **podman kube play** [*options*] *file.yml|-*
@@ -30,6 +30,9 @@ Note: If the `:latest` tag is used, Podman will attempt to pull the image from a
 
 Note: The command `podman play kube` is an alias of `podman kube play`, and will perform the same function.
 
+Note: The command `podman kube down` can be used to stop and remove pods or containers based on the same Kubernetes YAML used
+by `podman kube play` to create them.
+
 `Kubernetes PersistentVolumeClaims`
 
 A Kubernetes PersistentVolumeClaim represents a Podman named volume. Only the PersistentVolumeClaim name is required by Podman to create a volume. Kubernetes annotations can be used to make use of the available options for Podman volumes.
@@ -145,11 +148,6 @@ The [username[:password]] to use to authenticate with the registry if required.
 If one or both values are not supplied, a command line prompt will appear and the
 value can be entered.  The password is entered without echo.
 
-#### **--down**
-
-Tears down the pods that were created by a previous run of `kube play`.  The pods are stopped and then
-removed.  Any volumes created are left intact.
-
 #### **--help**, **-h**
 
 Print usage statement
@@ -325,7 +323,7 @@ $ podman kube play demo.yml --network net1:ip=10.89.1.5 --network net2:ip=10.89.
 Please take into account that networks must be created first using podman-network-create(1).
 
 ## SEE ALSO
-**[podman(1)](podman.1.md)**, **[podman-kube(1)](podman-kube.1.md)**, **[podman-network-create(1)](podman-network-create.1.md)**, **[podman-generate-kube(1)](podman-generate-kube.1.md)**, **[containers-certs.d(5)](https://github.com/containers/image/blob/main/docs/containers-certs.d.5.md)**
+**[podman(1)](podman.1.md)**, **[podman-kube(1)](podman-kube.1.md)**, **[podman-kube-down(1)](podman-kube-down.1.md)**, **[podman-network-create(1)](podman-network-create.1.md)**, **[podman-generate-kube(1)](podman-generate-kube.1.md)**, **[containers-certs.d(5)](https://github.com/containers/image/blob/main/docs/containers-certs.d.5.md)**
 
 ## HISTORY
 December 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)
diff --git a/docs/source/markdown/podman-kube.1.md b/docs/source/markdown/podman-kube.1.md
index f815ffae2..7a6978a2b 100644
--- a/docs/source/markdown/podman-kube.1.md
+++ b/docs/source/markdown/podman-kube.1.md
@@ -14,7 +14,8 @@ file input.  Containers will be automatically started.
 
 | Command  | Man Page                                            | Description                                                                  |
 | -------  | --------------------------------------------------- | ---------------------------------------------------------------------------- |
-| play     | [podman-kube-play(1)](podman-kube-play.1.md)        | Create containers, pods or volumes based on Kubernetes YAML.                         |
+| down     | [podman-kube-down(1)](podman-kube-down.1.md)        | Remove containers and pods based on Kubernetes YAML.                          |
+| play     | [podman-kube-play(1)](podman-kube-play.1.md)        | Create containers, pods and volumes based on Kubernetes YAML.                 |
 
 ## SEE ALSO
-**[podman(1)](podman.1.md)**, **[podman-pod(1)](podman-pod.1.md)**, **[podman-container(1)](podman-container.1.md)**, **[podman-generate(1)](podman-generate.1.md)**, **[podman-kube-play(1)](podman-kube-play.1.md)**
+**[podman(1)](podman.1.md)**, **[podman-pod(1)](podman-pod.1.md)**, **[podman-container(1)](podman-container.1.md)**, **[podman-generate(1)](podman-generate.1.md)**, **[podman-kube-play(1)](podman-kube-play.1.md)**, **[podman-kube-down(1)](podman-kube-down.1.md)**
diff --git a/test/system/700-play.bats b/test/system/700-play.bats
index 72602a9e6..e1955cfd1 100644
--- a/test/system/700-play.bats
+++ b/test/system/700-play.bats
@@ -182,8 +182,11 @@ EOF
     run_podman container inspect --format "{{.HostConfig.NetworkMode}}" $infraID
     is "$output" "none" "network mode none is set for the container"
 
-    run_podman stop -a -t 0
-    run_podman pod rm -t 0 -f test_pod
+    run_podman kube down - < $PODMAN_TMPDIR/test.yaml
+    run_podman 125 inspect test_pod-test
+    is "$output" ".*Error: inspecting object: no such object: \"test_pod-test\""
+    run_podman pod rm -a
+    run_podman rm -a
 }
 
 @test "podman play with user from image" {
@@ -325,7 +328,6 @@ spec:
     - name: TERM
       value: xterm
     - name: container
-
       value: podman
     image: quay.io/libpod/userimage
     name: test
@@ -353,6 +355,9 @@ status: {}
     run_podman inspect --format "{{.HostConfig.LogConfig.Type}}" test_pod-test
     is "$output" "$default_driver" "play kube uses default log driver"
 
-    run_podman stop -a -t 0
-    run_podman pod rm -t 0 -f test_pod
+    run_podman kube down $PODMAN_TMPDIR/test.yaml
+    run_podman 125 inspect test_pod-test
+    is "$output" ".*Error: inspecting object: no such object: \"test_pod-test\""
+    run_podman pod rm -a
+    run_podman rm -a
 }