Fix eviction dry-run

pkg/registry/core/pod/storage/BUILD

-package(default_visibility = ["//visibility:public"])
-
-load(
-    "@io_bazel_rules_go//go:def.bzl",
-    "go_library",
-    "go_test",
-)
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_test(
     name = "go_default_test",
@@ -20,6 +14,7 @@ go_test(
         "//pkg/registry/registrytest:go_default_library",
         "//pkg/securitycontext:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/api/apitesting:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/equality:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
@@ -27,7 +22,9 @@ go_test(
         "//staging/src/k8s.io/apimachinery/pkg/fields:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/labels:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/diff:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/example/v1:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/endpoints/request:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/registry/generic:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/registry/generic/registry:go_default_library",
@@ -46,6 +43,7 @@ go_library(
         "storage.go",
     ],
     importpath = "k8s.io/kubernetes/pkg/registry/core/pod/storage",
+    visibility = ["//visibility:public"],
     deps = [
         "//pkg/api/pod:go_default_library",
         "//pkg/apis/core:go_default_library",
@@ -85,4 +83,5 @@ filegroup(
     name = "all-srcs",
     srcs = [":package-srcs"],
     tags = ["automanaged"],
+    visibility = ["//visibility:public"],
 )

pkg/registry/core/pod/storage/eviction.go

@@ -19,6 +19,7 @@ package storage
 import (
 	"context"
 	"fmt"
+	"reflect"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/errors"
@@ -29,6 +30,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	genericregistry "k8s.io/apiserver/pkg/registry/generic/registry"
 	"k8s.io/apiserver/pkg/registry/rest"
+	"k8s.io/apiserver/pkg/util/dryrun"
 	"k8s.io/client-go/util/retry"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/policy"
@@ -77,11 +79,36 @@ func (r *EvictionREST) New() runtime.Object {
 	return &policy.Eviction{}
 }
 
+// Propagate dry-run takes the dry-run option from the request and pushes it into the eviction object.
+// It returns an error if they have non-matching dry-run options.
+func propagateDryRun(eviction *policy.Eviction, options *metav1.CreateOptions) (*metav1.DeleteOptions, error) {
+	if eviction.DeleteOptions == nil {
+		return &metav1.DeleteOptions{DryRun: options.DryRun}, nil
+	}
+	if len(eviction.DeleteOptions.DryRun) == 0 {
+		eviction.DeleteOptions.DryRun = options.DryRun
+		return eviction.DeleteOptions, nil
+	}
+	if len(options.DryRun) == 0 {
+		return eviction.DeleteOptions, nil
+	}
+
+	if !reflect.DeepEqual(options.DryRun, eviction.DeleteOptions.DryRun) {
+		return nil, fmt.Errorf("Non-matching dry-run options in request and content: %v and %v", options.DryRun, eviction.DeleteOptions.DryRun)
+	}
+	return eviction.DeleteOptions, nil
+}
+
 // Create attempts to create a new eviction.  That is, it tries to evict a pod.
 func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createValidation rest.ValidateObjectFunc, options *metav1.CreateOptions) (runtime.Object, error) {
 	eviction := obj.(*policy.Eviction)
 
-	obj, err := r.store.Get(ctx, eviction.Name, &metav1.GetOptions{})
+	deletionOptions, err := propagateDryRun(eviction, options)
+	if err != nil {
+		return nil, err
+	}
+
+	obj, err = r.store.Get(ctx, eviction.Name, &metav1.GetOptions{})
 	if err != nil {
 		return nil, err
 	}
@@ -89,7 +116,7 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 	// Evicting a terminal pod should result in direct deletion of pod as it already caused disruption by the time we are evicting.
 	// There is no need to check for pdb.
 	if pod.Status.Phase == api.PodSucceeded || pod.Status.Phase == api.PodFailed {
-		_, _, err = r.store.Delete(ctx, eviction.Name, eviction.DeleteOptions)
+		_, _, err = r.store.Delete(ctx, eviction.Name, deletionOptions)
 		if err != nil {
 			return nil, err
 		}
@@ -118,7 +145,7 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 
 			// If it was false already, or if it becomes false during the course of our retries,
 			// raise an error marked as a 429.
-			if err := r.checkAndDecrement(pod.Namespace, pod.Name, pdb); err != nil {
+			if err := r.checkAndDecrement(pod.Namespace, pod.Name, pdb, dryrun.IsDryRun(deletionOptions.DryRun)); err != nil {
 				return err
 			}
 		}
@@ -138,11 +165,6 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 	// At this point there was either no PDB or we succeeded in decrementing
 
 	// Try the delete
-	deletionOptions := eviction.DeleteOptions
-	if deletionOptions == nil {
-		// default to non-nil to trigger graceful deletion
-		deletionOptions = &metav1.DeleteOptions{}
-	}
 	_, _, err = r.store.Delete(ctx, eviction.Name, deletionOptions)
 	if err != nil {
 		return nil, err
@@ -153,7 +175,7 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 }
 
 // checkAndDecrement checks if the provided PodDisruptionBudget allows any disruption.
-func (r *EvictionREST) checkAndDecrement(namespace string, podName string, pdb policy.PodDisruptionBudget) error {
+func (r *EvictionREST) checkAndDecrement(namespace string, podName string, pdb policy.PodDisruptionBudget, dryRun bool) error {
 	if pdb.Status.ObservedGeneration < pdb.Generation {
 		// TODO(mml): Add a Retry-After header.  Once there are time-based
 		// budgets, we can sometimes compute a sensible suggested value.  But
@@ -179,6 +201,12 @@ func (r *EvictionREST) checkAndDecrement(namespace string, podName string, pdb p
 	if pdb.Status.DisruptedPods == nil {
 		pdb.Status.DisruptedPods = make(map[string]metav1.Time)
 	}
+
+	// If this is a dry-run, we don't need to go any further than that.
+	if dryRun == true {
+		return nil
+	}
+
 	// Eviction handler needs to inform the PDB controller that it is about to delete a pod
 	// so it should not consider it as available in calculations when updating PodDisruptions allowed.
 	// If the pod is not deleted within a reasonable time limit PDB controller will assume that it won't

pkg/registry/core/pod/storage/eviction_test.go

@@ -17,15 +17,24 @@ limitations under the License.
 package storage
 
 import (
+	"context"
 	"testing"
 
+	"k8s.io/apimachinery/pkg/api/apitesting"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	examplev1 "k8s.io/apiserver/pkg/apis/example/v1"
 	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/registry/generic"
+	genericregistry "k8s.io/apiserver/pkg/registry/generic/registry"
+	"k8s.io/apiserver/pkg/storage"
+	etcdtesting "k8s.io/apiserver/pkg/storage/etcd/testing"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/policy"
 	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/fake"
+	"k8s.io/kubernetes/pkg/registry/registrytest"
 )
 
 func TestEviction(t *testing.T) {
@@ -163,3 +172,119 @@ func TestEviction(t *testing.T) {
 		})
 	}
 }
+
+type FailDeleteUpdateStorage struct {
+	storage.Interface
+}
+
+func (f FailDeleteUpdateStorage) Delete(ctx context.Context, key string, out runtime.Object, precondition *storage.Preconditions) error {
+	return storage.NewKeyNotFoundError(key, 0)
+}
+
+func (f FailDeleteUpdateStorage) GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool,
+	preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, suggestion ...runtime.Object) error {
+	return storage.NewKeyNotFoundError(key, 0)
+}
+
+var scheme = runtime.NewScheme()
+var codecs = serializer.NewCodecFactory(scheme)
+
+func newFailDeleteUpdateStorage(t *testing.T) (*REST, *etcdtesting.EtcdTestServer) {
+	etcdStorage, server := registrytest.NewEtcdStorage(t, "")
+	restOptions := generic.RESTOptions{
+		StorageConfig:           etcdStorage,
+		Decorator:               generic.UndecoratedStorage,
+		DeleteCollectionWorkers: 3,
+		ResourcePrefix:          "pods",
+	}
+	storage := NewStorage(restOptions, nil, nil, nil)
+	storage.Pod.Store.Storage = genericregistry.DryRunnableStorage{
+		Storage: FailDeleteUpdateStorage{storage.Pod.Store.Storage.Storage},
+		Codec:   apitesting.TestStorageCodec(codecs, examplev1.SchemeGroupVersion),
+	}
+	return storage.Pod, server
+}
+
+func TestEvictionDryRun(t *testing.T) {
+	testcases := []struct {
+		name            string
+		evictionOptions *metav1.DeleteOptions
+		requestOptions  *metav1.CreateOptions
+		pod             *api.Pod
+		pdbs            []runtime.Object
+	}{
+		{
+			name:            "just request-options",
+			requestOptions:  &metav1.CreateOptions{DryRun: []string{"All"}},
+			evictionOptions: &metav1.DeleteOptions{},
+			pod: func() *api.Pod {
+				pod := validNewPod()
+				pod.Labels = map[string]string{"a": "true"}
+				pod.Spec.NodeName = "foo"
+				return pod
+			}(),
+		},
+		{
+			name:            "just eviction-options",
+			requestOptions:  &metav1.CreateOptions{},
+			evictionOptions: &metav1.DeleteOptions{DryRun: []string{"All"}},
+			pod: func() *api.Pod {
+				pod := validNewPod()
+				pod.Labels = map[string]string{"a": "true"}
+				pod.Spec.NodeName = "foo"
+				return pod
+			}(),
+		},
+		{
+			name:            "both options",
+			evictionOptions: &metav1.DeleteOptions{DryRun: []string{"All"}},
+			requestOptions:  &metav1.CreateOptions{DryRun: []string{"All"}},
+			pod: func() *api.Pod {
+				pod := validNewPod()
+				pod.Labels = map[string]string{"a": "true"}
+				pod.Spec.NodeName = "foo"
+				return pod
+			}(),
+		},
+		{
+			name:            "with pdbs",
+			evictionOptions: &metav1.DeleteOptions{DryRun: []string{"All"}},
+			requestOptions:  &metav1.CreateOptions{DryRun: []string{"All"}},
+			pod: func() *api.Pod {
+				pod := validNewPod()
+				pod.Labels = map[string]string{"a": "true"}
+				pod.Spec.NodeName = "foo"
+				return pod
+			}(),
+			pdbs: []runtime.Object{&policy.PodDisruptionBudget{
+				ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "default"},
+				Spec:       policy.PodDisruptionBudgetSpec{Selector: &metav1.LabelSelector{MatchLabels: map[string]string{"a": "true"}}},
+				Status:     policy.PodDisruptionBudgetStatus{PodDisruptionsAllowed: 1},
+			}},
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.name, func(t *testing.T) {
+			testContext := genericapirequest.WithNamespace(genericapirequest.NewContext(), metav1.NamespaceDefault)
+			storage, server := newFailDeleteUpdateStorage(t)
+			defer server.Terminate(t)
+			defer storage.Store.DestroyFunc()
+
+			pod := validNewPod()
+			pod.Labels = map[string]string{"a": "true"}
+			pod.Spec.NodeName = "foo"
+			if _, err := storage.Create(testContext, pod, nil, &metav1.CreateOptions{}); err != nil {
+				t.Error(err)
+			}
+
+			client := fake.NewSimpleClientset(tc.pdbs...)
+			evictionRest := newEvictionStorage(storage.Store, client.Policy())
+			eviction := &policy.Eviction{ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "default"}, DeleteOptions: tc.evictionOptions}
+			_, err := evictionRest.Create(testContext, eviction, nil, tc.requestOptions)
+			if err != nil {
+				t.Fatalf("Failed to run eviction: %v", err)
+			}
+		})
+	}
+}