Repository: gardener/machine-controller-manager (go)

Issue:
Machines are being force drained
**What happened**:
Machines are being force drained (before drain timeout) instead of a regular drain. This leads to disruption of PDBs and serial PV detachments causing downtimes.

**What you expected to happen**:
Machines to not be force drained before hitting drain timeout. 

**How to reproduce it (as minimally and precisely as possible)**:
Take a cluster with several nodes running smoothly over the default drain timeout period. And now delete the machine backing this node. Force drain is triggered (not always) but in many cases.

**Anything else we need to know**:
- This is most likely a regression due to https://github.com/gardener/machine-controller-manager/pull/492, where machine phase change to terminating state was moved in the code. This caused the drain to consider an old timeStamp leading to force drains. 
- Refer [machineSet deletion](https://github.com/gardener/machine-controller-manager/blob/master/pkg/controller/machineset.go#L641-L662). 

**Environment**:
MCM in-tree v0.34.3. OOT is unaffected by this.

/priority blocker
/kind regression

Pull request description:
Set Machine Phase to Terminating & make drain calculations based on deletionTimestamp
**What this PR does / why we need it**:
This PR fixes the race condition that triggers force deletion of machines which are less than drain timeout minutes old. Fixes regressions from #492 . 

**Which issue(s) this PR fixes**:
Fixes #563 

**Special notes for your reviewer**:

**Release note**:
<!--  Write your release note:
1. Enter your release note in the below block.
2. If no release note is required, just write "NONE" within the block.

Format of block header: <category> <target_group>
Possible values:
- category:       improvement|noteworthy
- target_group:   user|operator|developer
-->
```improvement operator
Set Machine Phase to Terminating before draining. 
```
```noteworthy operator
Machine force deletion computation is based on deletionTimestamp instead of LastUpdatedTimestamp. 
```
/invite @guydaichs 

Patch:
diff --git a/pkg/controller/machine.go b/pkg/controller/machine.go
index 9e6bb3ae9..e95e9c2d1 100644
--- a/pkg/controller/machine.go
+++ b/pkg/controller/machine.go
@@ -42,6 +42,7 @@ import (
 	"github.com/gardener/machine-controller-manager/pkg/apis/machine/v1alpha1"
 	"github.com/gardener/machine-controller-manager/pkg/apis/machine/validation"
 	"github.com/gardener/machine-controller-manager/pkg/driver"
+	utiltime "github.com/gardener/machine-controller-manager/pkg/util/time"
 )
 
 const (
@@ -624,9 +625,37 @@ func (c *controller) machineDelete(machine *v1alpha1.Machine, driver driver.Driv
 			forceDeleteLabelPresent = machine.Labels["force-deletion"] == "True"
 		)
 
-		// Timeout value obtained by subtracting last operation with expected time out period
-		timeOut := metav1.Now().Add(-timeOutDuration).Sub(machine.Status.CurrentStatus.LastUpdateTime.Time)
-		timeOutOccurred = timeOut > 0
+		if machine.Status.CurrentStatus.Phase != v1alpha1.MachineTerminating {
+			lastOperation := v1alpha1.LastOperation{
+				Description:    "Deleting machine from cloud provider",
+				State:          v1alpha1.MachineStateProcessing,
+				Type:           v1alpha1.MachineOperationDelete,
+				LastUpdateTime: metav1.Now(),
+			}
+			currentStatus := v1alpha1.CurrentStatus{
+				Phase:          v1alpha1.MachineTerminating,
+				TimeoutActive:  false,
+				LastUpdateTime: metav1.Now(),
+			}
+
+			err = c.deleteBootstrapToken(machine.Name)
+			if err != nil {
+				klog.Warning(err)
+			}
+
+			machine, err = c.updateMachineStatus(machine, lastOperation, currentStatus)
+			if err != nil && apierrors.IsNotFound(err) {
+				// Object no longer exists and has been deleted
+				klog.Warning(err)
+				return nil
+			} else if err != nil {
+				// Any other type of errors
+				klog.Error(err)
+				return err
+			}
+		}
+
+		timeOutOccurred = utiltime.HasTimeOutOccurred(*machine.DeletionTimestamp, timeOutDuration)
 
 		if forceDeleteLabelPresent || timeOutOccurred {
 			// To perform forceful machine drain/delete either one of the below conditions must be satified
@@ -638,11 +667,18 @@ func (c *controller) machineDelete(machine *v1alpha1.Machine, driver driver.Driv
 			maxEvictRetries = 1
 
 			klog.V(2).Infof(
-				"Force deletion has been triggerred for machine %q due to ForceDeletionLabel:%t, Timeout:%t",
+				"Force delete/drain has been triggerred for machine %q due to Label:%t, timeout:%t",
 				machine.Name,
 				forceDeleteLabelPresent,
 				timeOutOccurred,
 			)
+		} else {
+			klog.V(2).Infof(
+				"Normal delete/drain has been triggerred for machine %q with drain-timeout:%v & maxEvictRetries:%d",
+				machine.Name,
+				timeOutDuration,
+				maxEvictRetries,
+			)
 		}
 
 		// If machine was created on the cloud provider
@@ -660,36 +696,6 @@ func (c *controller) machineDelete(machine *v1alpha1.Machine, driver driver.Driv
 			}
 		}
 
-		if machine.Status.CurrentStatus.Phase != v1alpha1.MachineTerminating {
-			lastOperation := v1alpha1.LastOperation{
-				Description:    "Deleting machine from cloud provider",
-				State:          v1alpha1.MachineStateProcessing,
-				Type:           v1alpha1.MachineOperationDelete,
-				LastUpdateTime: metav1.Now(),
-			}
-			currentStatus := v1alpha1.CurrentStatus{
-				Phase:          v1alpha1.MachineTerminating,
-				TimeoutActive:  false,
-				LastUpdateTime: metav1.Now(),
-			}
-
-			err = c.deleteBootstrapToken(machine.Name)
-			if err != nil {
-				klog.Warning(err)
-			}
-
-			machine, err = c.updateMachineStatus(machine, lastOperation, currentStatus)
-			if err != nil && apierrors.IsNotFound(err) {
-				// Object no longer exists and has been deleted
-				klog.Warning(err)
-				return nil
-			} else if err != nil {
-				// Any other type of errors
-				klog.Error(err)
-				return err
-			}
-		}
-
 		if machineID != "" && nodeName != "" {
 			// Begin drain logic only when the nodeName & providerID exist's for the machine
 			buf := bytes.NewBuffer([]byte{})
diff --git a/pkg/util/provider/machinecontroller/machine_util.go b/pkg/util/provider/machinecontroller/machine_util.go
index 6efa84c8a..fce97052c 100644
--- a/pkg/util/provider/machinecontroller/machine_util.go
+++ b/pkg/util/provider/machinecontroller/machine_util.go
@@ -40,6 +40,7 @@ import (
 	"github.com/gardener/machine-controller-manager/pkg/util/provider/machinecodes/status"
 	"github.com/gardener/machine-controller-manager/pkg/util/provider/machineutils"
 	utilstrings "github.com/gardener/machine-controller-manager/pkg/util/strings"
+	utiltime "github.com/gardener/machine-controller-manager/pkg/util/time"
 
 	corev1 "k8s.io/api/core/v1"
 	v1 "k8s.io/api/core/v1"
@@ -912,9 +913,7 @@ func (c *controller) drainNode(deleteMachineRequest *driver.DeleteMachineRequest
 	if skipDrain {
 		state = v1alpha1.MachineStateProcessing
 	} else {
-		// Timeout value obtained by subtracting last operation with expected time out period
-		timeOut := metav1.Now().Add(-timeOutDuration).Sub(machine.Status.CurrentStatus.LastUpdateTime.Time)
-		timeOutOccurred = timeOut > 0
+		timeOutOccurred = utiltime.HasTimeOutOccurred(*machine.DeletionTimestamp, timeOutDuration)
 
 		if forceDeleteLabelPresent || timeOutOccurred {
 			// To perform forceful machine drain/delete either one of the below conditions must be satified
diff --git a/pkg/util/time/time.go b/pkg/util/time/time.go
new file mode 100644
index 000000000..21a5fe7f9
--- /dev/null
+++ b/pkg/util/time/time.go
@@ -0,0 +1,31 @@
+/*
+Copyright (c) 2020 SAP SE or an SAP affiliate company. All rights reserved.
+
+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 time is used to provide the core functionalities of machine-controller-manager
+package time
+
+import (
+	"time"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// HasTimeOutOccurred returns true, when time.Now() is more than time + period
+func HasTimeOutOccurred(timeStamp metav1.Time, period time.Duration) bool {
+	// Timeout value obtained by subtracting last operation with expected time out period
+	timeOut := metav1.Now().Add(-period).Sub(timeStamp.Time)
+	return timeOut > 0
+}


Test patch:
diff --git a/pkg/controller/controller_suite_test.go b/pkg/controller/controller_suite_test.go
index aaff5c131..fa0960182 100644
--- a/pkg/controller/controller_suite_test.go
+++ b/pkg/controller/controller_suite_test.go
@@ -312,6 +312,8 @@ func newMachines(
 		labels = make(map[string]string, 0)
 	}
 
+	currentTime := metav1.Now()
+
 	for i := range machines {
 		m := &v1alpha1.Machine{
 			TypeMeta: metav1.TypeMeta{
@@ -324,6 +326,7 @@ func newMachines(
 				Labels:            labels,
 				Annotations:       annotations,
 				CreationTimestamp: metav1.Now(),
+				DeletionTimestamp: &currentTime,
 			},
 			Spec: *newMachineSpec(&specTemplate.Spec, i),
 		}
diff --git a/pkg/util/provider/machinecontroller/controller_suite_test.go b/pkg/util/provider/machinecontroller/controller_suite_test.go
index 586731e88..cc587a998 100644
--- a/pkg/util/provider/machinecontroller/controller_suite_test.go
+++ b/pkg/util/provider/machinecontroller/controller_suite_test.go
@@ -335,6 +335,7 @@ func newMachines(
 				Labels:            labels,
 				Annotations:       annotations,
 				CreationTimestamp: creationTimestamp,
+				DeletionTimestamp: &creationTimestamp, //TODO: Add parametrize this
 			},
 			Spec: *newMachineSpec(&specTemplate.Spec, i),
 		}
diff --git a/pkg/util/provider/machinecontroller/machine_test.go b/pkg/util/provider/machinecontroller/machine_test.go
index 1bec6fec1..1d6c56bbd 100644
--- a/pkg/util/provider/machinecontroller/machine_test.go
+++ b/pkg/util/provider/machinecontroller/machine_test.go
@@ -1684,6 +1684,115 @@ var _ = Describe("machine", func() {
 					),
 				},
 			}),
+			Entry("Drain machine failure before drain timeout, hence deletion fails", &data{
+				setup: setup{
+					secrets: []*corev1.Secret{
+						{
+							ObjectMeta: *newObjectMeta(objMeta, 0),
+						},
+					},
+					machineClasses: []*v1alpha1.MachineClass{
+						{
+							ObjectMeta: *newObjectMeta(objMeta, 0),
+							SecretRef:  newSecretReference(objMeta, 0),
+						},
+					},
+					machines: newMachines(
+						1,
+						&v1alpha1.MachineTemplateSpec{
+							ObjectMeta: *newObjectMeta(objMeta, 0),
+							Spec: v1alpha1.MachineSpec{
+								Class: v1alpha1.ClassSpec{
+									Kind: "MachineClass",
+									Name: "machine-0",
+								},
+								ProviderID: "fakeID",
+							},
+						},
+						&v1alpha1.MachineStatus{
+							Node: "fakeNode",
+							CurrentStatus: v1alpha1.CurrentStatus{
+								Phase:          v1alpha1.MachineTerminating,
+								LastUpdateTime: metav1.NewTime(time.Now().Add(-3 * time.Minute)),
+							},
+							LastOperation: v1alpha1.LastOperation{
+								Description:    machineutils.InitiateDrain,
+								State:          v1alpha1.MachineStateProcessing,
+								Type:           v1alpha1.MachineOperationDelete,
+								LastUpdateTime: metav1.NewTime(time.Now().Add(-3 * time.Minute)),
+							},
+						},
+						nil,
+						map[string]string{
+							machineutils.MachinePriority: "3",
+						},
+						map[string]string{
+							"node": "fakeID-0",
+						},
+						true,
+						metav1.NewTime(time.Now().Add(-3*time.Minute)),
+					),
+					nodes: []*corev1.Node{
+						{
+							ObjectMeta: metav1.ObjectMeta{
+								Name: "fakeID-0",
+							},
+						},
+					},
+					fakeResourceActions: &customfake.ResourceActions{
+						Node: customfake.Actions{
+							Update: "Failed to update node",
+						},
+					},
+				},
+				action: action{
+					machine: "machine-0",
+					fakeDriver: &driver.FakeDriver{
+						VMExists:   true,
+						ProviderID: "fakeID-0",
+						NodeName:   "fakeNode-0",
+						Err:        nil,
+					},
+				},
+				expect: expect{
+					err:   fmt.Errorf("failed to create update conditions for node \"fakeID-0\": Failed to update node"),
+					retry: machineutils.ShortRetry,
+					machine: newMachine(
+						&v1alpha1.MachineTemplateSpec{
+							ObjectMeta: *newObjectMeta(objMeta, 0),
+							Spec: v1alpha1.MachineSpec{
+								Class: v1alpha1.ClassSpec{
+									Kind: "MachineClass",
+									Name: "machine-0",
+								},
+								ProviderID: "fakeID",
+							},
+						},
+						&v1alpha1.MachineStatus{
+							Node: "fakeNode",
+							CurrentStatus: v1alpha1.CurrentStatus{
+								Phase:          v1alpha1.MachineTerminating,
+								LastUpdateTime: metav1.Now(),
+							},
+							LastOperation: v1alpha1.LastOperation{
+								Description:    fmt.Sprintf("Drain failed due to failure in update of node conditions - %s. Will retry in next sync. %s", "failed to create update conditions for node \"fakeID-0\": Failed to update node", machineutils.InitiateDrain),
+								State:          v1alpha1.MachineStateFailed,
+								Type:           v1alpha1.MachineOperationDelete,
+								LastUpdateTime: metav1.Now(),
+							},
+						},
+						nil,
+						map[string]string{
+							machineutils.MachinePriority: "3",
+						},
+						map[string]string{
+							"node": "fakeID-0",
+						},
+						true,
+						metav1.Now(),
+					),
+				},
+			}),
 			Entry("Drain machine failure after drain timeout, hence deletion continues", &data{
 				setup: setup{
 					secrets: []*corev1.Secret{
@@ -1730,7 +1839,7 @@ var _ = Describe("machine", func() {
 							"node": "fakeID-0",
 						},
 						true,
-						metav1.Now(),
+						metav1.NewTime(time.Now().Add(-3*time.Hour)),
 					),
 					nodes: []*corev1.Node{
 						{
diff --git a/pkg/util/time/time_suite_test.go b/pkg/util/time/time_suite_test.go
new file mode 100644
index 000000000..69f1ac6f7
--- /dev/null
+++ b/pkg/util/time/time_suite_test.go
@@ -0,0 +1,13 @@
+package time_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestTime(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Time Suite")
+}
diff --git a/pkg/util/time/time_test.go b/pkg/util/time/time_test.go
new file mode 100644
index 000000000..d64a69a72
--- /dev/null
+++ b/pkg/util/time/time_test.go
@@ -0,0 +1,77 @@
+/*
+Copyright (c) 2017 SAP SE or an SAP affiliate company. All rights reserved.
+
+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 time
+
+import (
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/ginkgo/extensions/table"
+	. "github.com/onsi/gomega"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+var _ = Describe("time", func() {
+	Describe("#hasTimeOutOccurred", func() {
+		type setup struct {
+			timeStamp metav1.Time
+			period    time.Duration
+		}
+		type action struct {
+		}
+		type expect struct {
+			timeOutOccurred bool
+		}
+		type data struct {
+			setup  setup
+			action action
+			expect expect
+		}
+		DescribeTable("##TimeOut scenarios",
+			func(data *data) {
+				timeOutOccurred := HasTimeOutOccurred(data.setup.timeStamp, data.setup.period)
+				Expect(timeOutOccurred).To(Equal(data.expect.timeOutOccurred))
+			},
+			Entry("Time stamp is one hour ago and period is 30mins", &data{
+				setup: setup{
+					timeStamp: metav1.Time{Time: time.Now().Add(-time.Hour)},
+					period:    30 * time.Minute,
+				},
+				expect: expect{
+					timeOutOccurred: true,
+				},
+			}),
+			Entry("Time stamp is one hour ago and period is 90mins", &data{
+				setup: setup{
+					timeStamp: metav1.Time{Time: time.Now().Add(-time.Hour)},
+					period:    90 * time.Minute,
+				},
+				expect: expect{
+					timeOutOccurred: false,
+				},
+			}),
+			Entry("Time stamp is now and period is 5mins", &data{
+				setup: setup{
+					timeStamp: metav1.Time{Time: time.Now()},
+					period:    5 * time.Minute,
+				},
+				expect: expect{
+					timeOutOccurred: false,
+				},
+			}),
+		)
+	})
+})