From 564f0e9a2575dd64575454b2570511939911e17d Mon Sep 17 00:00:00 2001
From: Adrian Reber <areber@redhat.com>
Date: Tue, 7 Sep 2021 15:34:06 +0000
Subject: [PATCH] kubelet: add checkpoint/restore infrastructure

This adds the first infrastructure code parts to the kubelet
to support checkpoint/restore.

Signed-off-by: Adrian Reber <areber@redhat.com>
---
 pkg/kubelet/config/defaults.go | 1 +
 pkg/kubelet/kubelet.go         | 6 ++++++
 pkg/kubelet/kubelet_getters.go | 6 ++++++
 3 files changed, 13 insertions(+)

diff --git a/pkg/kubelet/config/defaults.go b/pkg/kubelet/config/defaults.go
index f2564e65d90..b438e0d25d5 100644
--- a/pkg/kubelet/config/defaults.go
+++ b/pkg/kubelet/config/defaults.go
@@ -28,4 +28,5 @@ const (
 	DefaultKubeletPluginContainersDirName    = "plugin-containers"
 	DefaultKubeletPodResourcesDirName        = "pod-resources"
 	KubeletPluginsDirSELinuxLabel            = "system_u:object_r:container_file_t:s0"
+	DefaultKubeletCheckpointsDirName         = "checkpoints"
 )
diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go
index 8482c60db13..5cb582dcedb 100644
--- a/pkg/kubelet/kubelet.go
+++ b/pkg/kubelet/kubelet.go
@@ -1229,6 +1229,7 @@ func (kl *Kubelet) RlimitStats() (*statsapi.RlimitStats, error) {
 // 2.  the pods directory
 // 3.  the plugins directory
 // 4.  the pod-resources directory
+// 5.  the checkpoint directory
 func (kl *Kubelet) setupDataDirs() error {
 	kl.rootDirectory = path.Clean(kl.rootDirectory)
 	pluginRegistrationDir := kl.getPluginsRegistrationDir()
@@ -1251,6 +1252,11 @@ func (kl *Kubelet) setupDataDirs() error {
 	if err := os.MkdirAll(kl.getPodResourcesDir(), 0750); err != nil {
 		return fmt.Errorf("error creating podresources directory: %v", err)
 	}
+	if utilfeature.DefaultFeatureGate.Enabled(features.ContainerCheckpoint) {
+		if err := os.MkdirAll(kl.getCheckpointsDir(), 0700); err != nil {
+			return fmt.Errorf("error creating checkpoint directory: %v", err)
+		}
+	}
 	if selinux.GetEnabled() {
 		err := selinux.SetFileLabel(pluginRegistrationDir, config.KubeletPluginsDirSELinuxLabel)
 		if err != nil {
diff --git a/pkg/kubelet/kubelet_getters.go b/pkg/kubelet/kubelet_getters.go
index dacb909bd10..1d393abd9dd 100644
--- a/pkg/kubelet/kubelet_getters.go
+++ b/pkg/kubelet/kubelet_getters.go
@@ -77,6 +77,12 @@ func (kl *Kubelet) getPluginDir(pluginName string) string {
 	return filepath.Join(kl.getPluginsDir(), pluginName)
 }
 
+// getCheckpointsDir returns a data directory name for checkpoints.
+// Checkpoints can be stored in this directory for further use.
+func (kl *Kubelet) getCheckpointsDir() string {
+	return filepath.Join(kl.getRootDir(), config.DefaultKubeletCheckpointsDirName)
+}
+
 // getVolumeDevicePluginsDir returns the full path to the directory under which plugin
 // directories are created.  Plugins can use these directories for data that
 // they need to persist.  Plugins should create subdirectories under this named