podman pod clone

implement podman pod clone, a command to create an exact copy of a pod while changing
certain config elements

current supported flags are:
--name change the pod name
--destroy remove the original pod
--start run the new pod on creation
and all infra-container related flags from podman pod create (namespaces etc)

resolves #12843

Signed-off-by: cdoern <cdoern@redhat.com>

2 files changed, 88 insertions, 0 deletions

diff --git a/cmd/podman/pods/clone.go b/cmd/podman/pods/clone.go
new file mode 100644
index 000000000..d95d74b05
--- /dev/null
+++ b/cmd/podman/pods/clone.go
@@ -0,0 +1,87 @@
+package pods
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/containers/common/pkg/completion"
+	"github.com/containers/podman/v4/cmd/podman/common"
+	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/libpod/define"
+	"github.com/containers/podman/v4/pkg/domain/entities"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+var (
+	podCloneDescription = `Create an exact copy of a pod and the containers within it`
+
+	podCloneCommand = &cobra.Command{
+		Use:               "clone [options] POD NAME",
+		Short:             "Clone an existing pod",
+		Long:              podCloneDescription,
+		RunE:              clone,
+		Args:              cobra.RangeArgs(1, 2),
+		ValidArgsFunction: common.AutocompleteClone,
+		Example:           `podman pod clone pod_name new_name`,
+	}
+)
+
+var (
+	podClone entities.PodCloneOptions
+)
+
+func cloneFlags(cmd *cobra.Command) {
+	flags := cmd.Flags()
+
+	destroyFlagName := "destroy"
+	flags.BoolVar(&podClone.Destroy, destroyFlagName, false, "destroy the original pod")
+
+	startFlagName := "start"
+	flags.BoolVar(&podClone.Start, startFlagName, false, "start the new pod")
+
+	nameFlagName := "name"
+	flags.StringVarP(&podClone.CreateOpts.Name, nameFlagName, "n", "", "name the new pod")
+	_ = podCloneCommand.RegisterFlagCompletionFunc(nameFlagName, completion.AutocompleteNone)
+
+	common.DefineCreateDefaults(&podClone.InfraOptions)
+	common.DefineCreateFlags(cmd, &podClone.InfraOptions, true, false)
+	podClone.InfraOptions.MemorySwappiness = -1 // this is not implemented for pods yet, need to set -1 default manually
+
+	// need to fill an empty ctr create option for each container for sane defaults
+	// for now, these cannot be used. The flag names conflict too much
+	// this makes sense since this is a pod command not a container command
+	// TODO: add support for container specific arguments/flags
+	common.DefineCreateDefaults(&podClone.PerContainerOptions)
+}
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Command: podCloneCommand,
+		Parent:  podCmd,
+	})
+
+	cloneFlags(podCloneCommand)
+}
+
+func clone(cmd *cobra.Command, args []string) error {
+	switch len(args) {
+	case 0:
+		return errors.Wrapf(define.ErrInvalidArg, "must specify at least 1 argument")
+	case 2:
+		podClone.CreateOpts.Name = args[1]
+	}
+
+	podClone.ID = args[0]
+	podClone.PerContainerOptions.IsClone = true
+	rep, err := registry.ContainerEngine().PodClone(context.Background(), podClone)
+	if err != nil {
+		if rep != nil {
+			fmt.Printf("pod %s created but error after creation\n", rep.Id)
+		}
+		return err
+	}
+
+	fmt.Println(rep.Id)
+
+	return nil
+}
diff --git a/cmd/podman/pods/create.go b/cmd/podman/pods/create.go
index e2f80bdbc..ca9d60174 100644
--- a/cmd/podman/pods/create.go
+++ b/cmd/podman/pods/create.go
@@ -64,6 +64,7 @@ func init() {
 	})
 	flags := createCommand.Flags()
 	flags.SetInterspersed(false)
+	common.DefineCreateDefaults(&infraOptions)
 	common.DefineCreateFlags(createCommand, &infraOptions, true, false)
 	common.DefineNetFlags(createCommand)