Add subcommand snapshot export of kwokctl

pkg/kwokctl/cmd/snapshot/export/export.go

@@ -0,0 +1,76 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package export is the export of external cluster
+package export
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"sigs.k8s.io/kwok/pkg/kwokctl/snapshot"
+)
+
+type flagpole struct {
+	Path       string
+	Kubeconfig string
+	Filters    []string
+}
+
+// NewCommand returns a new cobra.Command for cluster exporting.
+func NewCommand(ctx context.Context) *cobra.Command {
+	flags := &flagpole{}
+
+	cmd := &cobra.Command{
+		Args:  cobra.NoArgs,
+		Use:   "export",
+		Short: "Export the snapshots of external clusters",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runE(cmd.Context(), flags)
+		},
+	}
+	cmd.Flags().StringVar(&flags.Kubeconfig, "kubeconfig", flags.Kubeconfig, "Path to the kubeconfig file to use")
+	cmd.Flags().StringVar(&flags.Path, "path", "", "Path to the snapshot")
+	cmd.Flags().StringSliceVar(&flags.Filters, "filter", snapshot.Resources, "Filter the resources to export")
+	return cmd
+}
+
+func runE(ctx context.Context, flags *flagpole) error {
+	if flags.Path == "" {
+		return fmt.Errorf("path is required")
+	}
+	if _, err := os.Stat(flags.Path); err == nil {
+		return fmt.Errorf("file %q already exists", flags.Path)
+	}
+
+	file, err := os.Create(flags.Path)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = file.Close()
+	}()
+
+	err = snapshot.Save(ctx, flags.Kubeconfig, file, flags.Filters)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/kwokctl/cmd/snapshot/snapshot.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"sigs.k8s.io/kwok/pkg/kwokctl/cmd/snapshot/export"
 	"sigs.k8s.io/kwok/pkg/kwokctl/cmd/snapshot/restore"
 	"sigs.k8s.io/kwok/pkg/kwokctl/cmd/snapshot/save"
 )
@@ -38,5 +39,6 @@ func NewCommand(ctx context.Context) *cobra.Command {
 	}
 	cmd.AddCommand(save.NewCommand(ctx))
 	cmd.AddCommand(restore.NewCommand(ctx))
+	cmd.AddCommand(export.NewCommand(ctx))
 	return cmd
 }

site/content/en/docs/generated/kwokctl_snapshot.md

@@ -23,6 +23,7 @@ kwokctl snapshot [command] [flags]
 ### SEE ALSO
 
 * [kwokctl](kwokctl.md)	 - kwokctl is a tool to streamline the creation and management of clusters, with nodes simulated by kwok
+* [kwokctl snapshot export](kwokctl_snapshot_export.md)	 - Export the snapshots of external clusters
 * [kwokctl snapshot restore](kwokctl_snapshot_restore.md)	 - Restore the snapshot of the cluster
 * [kwokctl snapshot save](kwokctl_snapshot_save.md)	 - Save the snapshot of the cluster
 

site/content/en/docs/generated/kwokctl_snapshot_export.md

@@ -0,0 +1,29 @@
+## kwokctl snapshot export
+
+Export the snapshots of external clusters
+
+```
+kwokctl snapshot export [flags]
+```
+
+### Options
+
+```
+      --filter strings      Filter the resources to export (default [namespace,node,serviceaccount,configmap,secret,daemonset.apps,deployment.apps,replicaset.apps,statefulset.apps,cronjob.batch,job.batch,persistentvolumeclaim,persistentvolume,pod,service,endpoints])
+  -h, --help                help for export
+      --kubeconfig string   Path to the kubeconfig file to use
+      --path string         Path to the snapshot
+```
+
+### Options inherited from parent commands
+
+```
+  -c, --config stringArray   config path (default [~/.kwok/kwok.yaml])
+      --name string          cluster name (default "kwok")
+  -v, --v log-level          number for the log level verbosity (DEBUG, INFO, WARN, ERROR) or (-4, 0, 4, 8) (default INFO)
+```
+
+### SEE ALSO
+
+* [kwokctl snapshot](kwokctl_snapshot.md)	 - Snapshot [save, restore] one of cluster
+

site/content/en/docs/user/kwokctl-snapshot.md

@@ -43,3 +43,21 @@ which will handle the ownerReference so that the resources remain relative to ea
 ``` bash
 kwokctl snapshot restore --path cluster.yaml --format k8s
 ```
+
+## Export external cluster
+
+This like `kwokctl snapshot save --format k8s` but it will use the kubeconfig to connect to the cluster.
+This is useful when you want to save a cluster that is not managed by `kwokctl` and restore it on a cluster managed by `kwokctl`.
+
+``` bash
+kwokctl snapshot export --path external-snapshot.yaml --kubeconfig /path/to/kubeconfig
+```
+
+### Restore cluster
+
+Let's restore the cluster we just exported.
+
+``` bash
+kwokctl create cluster
+kwokctl snapshot restore --path external-snapshot.yaml --format k8s
+```