Postpone Deletion of a Persistent Volume Claim in case It Is Used by a Pod

cluster/centos/config-default.sh

@@ -120,7 +120,7 @@ export FLANNEL_NET=${FLANNEL_NET:-"172.16.0.0/16"}
 
 # Admission Controllers to invoke prior to persisting objects in cluster
 # If we included ResourceQuota, we should keep it at the end of the list to prevent incrementing quota usage prematurely.
-export ADMISSION_CONTROL=${ADMISSION_CONTROL:-"Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeClaimResize,DefaultTolerationSeconds,Priority,ResourceQuota"}
+export ADMISSION_CONTROL=${ADMISSION_CONTROL:-"Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeClaimResize,DefaultTolerationSeconds,Priority,PVCProtection,ResourceQuota"}
 
 # Extra options to set on the Docker command line.
 # This is useful for setting --insecure-registry for local registries.

cluster/gce/config-default.sh

@@ -294,7 +294,7 @@ if [[ -n "${GCE_GLBC_IMAGE:-}" ]]; then
 fi
 
 # Admission Controllers to invoke prior to persisting objects in cluster
-ADMISSION_CONTROL=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,PersistentVolumeClaimResize,DefaultTolerationSeconds,NodeRestriction,Priority
+ADMISSION_CONTROL=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,PersistentVolumeClaimResize,DefaultTolerationSeconds,NodeRestriction,Priority,PVCProtection
 
 if [[ "${ENABLE_POD_SECURITY_POLICY:-}" == "true" ]]; then
   ADMISSION_CONTROL="${ADMISSION_CONTROL},PodSecurityPolicy"

cluster/libvirt-coreos/util.sh

@@ -27,7 +27,7 @@ source "$KUBE_ROOT/cluster/common.sh"
 
 export LIBVIRT_DEFAULT_URI=qemu:///system
 export SERVICE_ACCOUNT_LOOKUP=${SERVICE_ACCOUNT_LOOKUP:-true}
-export ADMISSION_CONTROL=${ADMISSION_CONTROL:-Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,PersistentVolumeClaimResize,DefaultTolerationSeconds,ResourceQuota}
+export ADMISSION_CONTROL=${ADMISSION_CONTROL:-Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,PersistentVolumeClaimResize,DefaultTolerationSeconds,PVCProtection,ResourceQuota}
 readonly POOL=kubernetes
 readonly POOL_PATH=/var/lib/libvirt/images/kubernetes
 

cluster/vagrant/config-default.sh

@@ -56,7 +56,7 @@ MASTER_PASSWD="${MASTER_PASSWD:-vagrant}"
 
 # Admission Controllers to invoke prior to persisting objects in cluster
 # If we included ResourceQuota, we should keep it at the end of the list to prevent incrementing quota usage prematurely.
-ADMISSION_CONTROL=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,ResourceQuota
+ADMISSION_CONTROL=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,PVCProtection,ResourceQuota
 
 # Optional: Enable node logging.
 ENABLE_NODE_LOGGING=false
@@ -120,4 +120,3 @@ E2E_STORAGE_TEST_ENVIRONMENT=${KUBE_E2E_STORAGE_TEST_ENVIRONMENT:-false}
 
 # Default fallback NETWORK_IF_NAME, will be used in case when no 'VAGRANT-BEGIN' comments were defined in network-script
 export DEFAULT_NETWORK_IF_NAME="eth0"
-

cmd/kube-apiserver/app/options/BUILD

@@ -40,6 +40,7 @@ go_library(
         "//plugin/pkg/admission/noderestriction:go_default_library",
         "//plugin/pkg/admission/persistentvolume/label:go_default_library",
         "//plugin/pkg/admission/persistentvolume/resize:go_default_library",
+        "//plugin/pkg/admission/persistentvolumeclaim/pvcprotection:go_default_library",
         "//plugin/pkg/admission/podnodeselector:go_default_library",
         "//plugin/pkg/admission/podpreset:go_default_library",
         "//plugin/pkg/admission/podtolerationrestriction:go_default_library",

cmd/kube-apiserver/app/options/plugins.go

@@ -42,6 +42,7 @@ import (
 	"k8s.io/kubernetes/plugin/pkg/admission/noderestriction"
 	"k8s.io/kubernetes/plugin/pkg/admission/persistentvolume/label"
 	"k8s.io/kubernetes/plugin/pkg/admission/persistentvolume/resize"
+	"k8s.io/kubernetes/plugin/pkg/admission/persistentvolumeclaim/pvcprotection"
 	"k8s.io/kubernetes/plugin/pkg/admission/podnodeselector"
 	"k8s.io/kubernetes/plugin/pkg/admission/podpreset"
 	"k8s.io/kubernetes/plugin/pkg/admission/podtolerationrestriction"
@@ -81,4 +82,5 @@ func RegisterAllAdmissionPlugins(plugins *admission.Plugins) {
 	serviceaccount.Register(plugins)
 	setdefault.Register(plugins)
 	resize.Register(plugins)
+	pvcprotection.Register(plugins)
 }

cmd/kube-controller-manager/app/BUILD

@@ -79,6 +79,7 @@ go_library(
         "//pkg/controller/volume/attachdetach:go_default_library",
         "//pkg/controller/volume/expand:go_default_library",
         "//pkg/controller/volume/persistentvolume:go_default_library",
+        "//pkg/controller/volume/pvcprotection:go_default_library",
         "//pkg/features:go_default_library",
         "//pkg/quota/generic:go_default_library",
         "//pkg/quota/install:go_default_library",

cmd/kube-controller-manager/app/controllermanager.go

@@ -359,6 +359,7 @@ func NewControllerInitializers() map[string]InitFunc {
 	controllers["attachdetach"] = startAttachDetachController
 	controllers["persistentvolume-expander"] = startVolumeExpandController
 	controllers["clusterrole-aggregation"] = startClusterRoleAggregrationController
+	controllers["pvc-protection"] = startPVCProtectionController
 
 	return controllers
 }

cmd/kube-controller-manager/app/core.go

@@ -53,6 +53,7 @@ import (
 	"k8s.io/kubernetes/pkg/controller/volume/attachdetach"
 	"k8s.io/kubernetes/pkg/controller/volume/expand"
 	persistentvolumecontroller "k8s.io/kubernetes/pkg/controller/volume/persistentvolume"
+	"k8s.io/kubernetes/pkg/controller/volume/pvcprotection"
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/quota/generic"
 	quotainstall "k8s.io/kubernetes/pkg/quota/install"
@@ -376,3 +377,15 @@ func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
 
 	return true, nil
 }
+
+func startPVCProtectionController(ctx ControllerContext) (bool, error) {
+	if utilfeature.DefaultFeatureGate.Enabled(features.PVCProtection) {
+		go pvcprotection.NewPVCProtectionController(
+			ctx.InformerFactory.Core().V1().PersistentVolumeClaims(),
+			ctx.InformerFactory.Core().V1().Pods(),
+			ctx.ClientBuilder.ClientOrDie("pvc-protection-controller"),
+		).Run(1, ctx.Stop)
+		return true, nil
+	}
+	return false, nil
+}

pkg/controller/BUILD

@@ -133,6 +133,7 @@ filegroup(
         "//pkg/controller/volume/events:all-srcs",
         "//pkg/controller/volume/expand:all-srcs",
         "//pkg/controller/volume/persistentvolume:all-srcs",
+        "//pkg/controller/volume/pvcprotection:all-srcs",
     ],
     tags = ["automanaged"],
 )

pkg/controller/volume/pvcprotection/BUILD

@@ -0,0 +1,61 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["pvc_protection_controller.go"],
+    importpath = "k8s.io/kubernetes/pkg/controller/volume/pvcprotection",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/controller:go_default_library",
+        "//pkg/util/metrics:go_default_library",
+        "//pkg/volume/util:go_default_library",
+        "//pkg/volume/util/volumehelper:go_default_library",
+        "//vendor/github.com/golang/glog:go_default_library",
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//vendor/k8s.io/client-go/informers/core/v1:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes:go_default_library",
+        "//vendor/k8s.io/client-go/listers/core/v1:go_default_library",
+        "//vendor/k8s.io/client-go/tools/cache:go_default_library",
+        "//vendor/k8s.io/client-go/util/workqueue:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["pvc_protection_controller_test.go"],
+    importpath = "k8s.io/kubernetes/pkg/controller/volume/pvcprotection",
+    library = ":go_default_library",
+    deps = [
+        "//pkg/controller:go_default_library",
+        "//pkg/volume/util:go_default_library",
+        "//vendor/github.com/davecgh/go-spew/spew:go_default_library",
+        "//vendor/github.com/golang/glog:go_default_library",
+        "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/meta:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//vendor/k8s.io/client-go/informers:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/fake:go_default_library",
+        "//vendor/k8s.io/client-go/testing:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)