Merge pull request #66799 from noqcks/master

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.

Add validation for kube-scheduler configuration options

**What this PR does / why we need it**: This adds validation to the kube-scheduler so that we're not accepting bogus values to the kube-scheduler. As requested by @bsalamat in issue https://github.com/kubernetes/kubernetes/issues/66743

**Which issue(s) this PR fixes**:
Fixes #66743

**Special notes for your reviewer**:
- Not sure if this validation is too heavy handed. Would love some feedback.
- I started working on this before I realized @islinwb was also working on this same problem... https://github.com/kubernetes/kubernetes/pull/66787 I put this PR up anyways since I'm sure good code exists in both. I wasn't aware of the /assign command so didn't assign myself before starting work.
- I didn't have time to work on adding validation to deprecated cli options. If the rest of this looks ok, I can finish that up.
- I hope the location of IsValidSocketAddr is correct. Lmk if it isn't.

**Release note**:
```release-note
Adding validation to kube-scheduler at the API level
```

Kubernetes-commit: f3b98a08b05257fbc3c19b52ced70ea67c546b1e

pkg/apis/config/validation/validation.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2018 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 validation
+
+import (
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apiserver/pkg/apis/config"
+)
+
+// ValidateLeaderElectionConfiguration ensures validation of the LeaderElectionConfiguration struct
+func ValidateLeaderElectionConfiguration(cc *config.LeaderElectionConfiguration, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	if !cc.LeaderElect {
+		return allErrs
+	}
+	if cc.LeaseDuration.Duration <= 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("leaseDuration"), cc.LeaseDuration, "must be greater than zero"))
+	}
+	if cc.RenewDeadline.Duration <= 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("renewDeadline"), cc.LeaseDuration, "must be greater than zero"))
+	}
+	if cc.RetryPeriod.Duration <= 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("retryPeriod"), cc.RetryPeriod, "must be greater than zero"))
+	}
+	if cc.LeaseDuration.Duration < cc.RenewDeadline.Duration {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("leaseDuration"), cc.RenewDeadline, "LeaseDuration must be greater than RenewDeadline"))
+	}
+	if len(cc.ResourceLock) == 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("resourceLock"), cc.RenewDeadline, "resourceLock is required"))
+	}
+	return allErrs
+}

pkg/apis/config/validation/validation_test.go

@@ -0,0 +1,112 @@
+/*
+Copyright 2018 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 validation
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apiserver/pkg/apis/config"
+	"testing"
+	"time"
+)
+
+func TestValidateLeaderElectionConfiguration(t *testing.T) {
+	validConfig := &config.LeaderElectionConfiguration{
+		ResourceLock:  "configmap",
+		LeaderElect:   true,
+		LeaseDuration: metav1.Duration{Duration: 30 * time.Second},
+		RenewDeadline: metav1.Duration{Duration: 15 * time.Second},
+		RetryPeriod:   metav1.Duration{Duration: 5 * time.Second},
+	}
+
+	renewDeadlineExceedsLeaseDuration := validConfig.DeepCopy()
+	renewDeadlineExceedsLeaseDuration.RenewDeadline = metav1.Duration{Duration: 45 * time.Second}
+
+	renewDeadlineZero := validConfig.DeepCopy()
+	renewDeadlineZero.RenewDeadline = metav1.Duration{Duration: 0 * time.Second}
+
+	leaseDurationZero := validConfig.DeepCopy()
+	leaseDurationZero.LeaseDuration = metav1.Duration{Duration: 0 * time.Second}
+
+	negativeValForRetryPeriod := validConfig.DeepCopy()
+	negativeValForRetryPeriod.RetryPeriod = metav1.Duration{Duration: -45 * time.Second}
+
+	negativeValForLeaseDuration := validConfig.DeepCopy()
+	negativeValForLeaseDuration.LeaseDuration = metav1.Duration{Duration: -45 * time.Second}
+
+	negativeValForRenewDeadline := validConfig.DeepCopy()
+	negativeValForRenewDeadline.RenewDeadline = metav1.Duration{Duration: -45 * time.Second}
+
+	LeaderElectButLeaderElectNotEnabled := validConfig.DeepCopy()
+	LeaderElectButLeaderElectNotEnabled.LeaderElect = false
+	LeaderElectButLeaderElectNotEnabled.LeaseDuration = metav1.Duration{Duration: -45 * time.Second}
+
+	resourceLockNotDefined := validConfig.DeepCopy()
+	resourceLockNotDefined.ResourceLock = ""
+
+	scenarios := map[string]struct {
+		expectedToFail bool
+		config         *config.LeaderElectionConfiguration
+	}{
+		"good": {
+			expectedToFail: false,
+			config:         validConfig,
+		},
+		"good-dont-check-leader-config-if-not-enabled": {
+			expectedToFail: false,
+			config:         LeaderElectButLeaderElectNotEnabled,
+		},
+		"bad-renew-deadline-exceeds-lease-duration": {
+			expectedToFail: true,
+			config:         renewDeadlineExceedsLeaseDuration,
+		},
+		"bad-negative-value-for-retry-period": {
+			expectedToFail: true,
+			config:         negativeValForRetryPeriod,
+		},
+		"bad-negative-value-for-lease-duration": {
+			expectedToFail: true,
+			config:         negativeValForLeaseDuration,
+		},
+		"bad-negative-value-for-renew-deadline": {
+			expectedToFail: true,
+			config:         negativeValForRenewDeadline,
+		},
+		"bad-renew-deadline-zero": {
+			expectedToFail: true,
+			config:         renewDeadlineZero,
+		},
+		"bad-lease-duration-zero": {
+			expectedToFail: true,
+			config:         leaseDurationZero,
+		},
+		"bad-resource-lock-not-defined": {
+			expectedToFail: true,
+			config:         resourceLockNotDefined,
+		},
+	}
+
+	for name, scenario := range scenarios {
+		errs := ValidateLeaderElectionConfiguration(scenario.config, field.NewPath("leaderElectionConfiguration"))
+		if len(errs) == 0 && scenario.expectedToFail {
+			t.Errorf("Unexpected success for scenario: %s", name)
+		}
+		if len(errs) > 0 && !scenario.expectedToFail {
+			t.Errorf("Unexpected failure for scenario: %s - %+v", name, errs)
+		}
+	}
+}