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
```

cmd/kube-scheduler/app/options/BUILD

@@ -17,6 +17,7 @@ go_library(
         "//pkg/scheduler/apis/config:go_default_library",
         "//pkg/scheduler/apis/config/scheme:go_default_library",
         "//pkg/scheduler/apis/config/v1alpha1:go_default_library",
+        "//pkg/scheduler/apis/config/validation:go_default_library",
         "//pkg/scheduler/factory:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/config:go_default_library",
@@ -24,6 +25,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer/json:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/uuid:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/server/options:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//staging/src/k8s.io/client-go/informers:go_default_library",
@@ -58,6 +60,7 @@ filegroup(
 go_test(
     name = "go_default_test",
     srcs = [
+        "deprecated_test.go",
         "insecure_serving_test.go",
         "options_test.go",
     ],

cmd/kube-scheduler/app/options/deprecated.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"github.com/spf13/pflag"
 
+	"k8s.io/apimachinery/pkg/util/validation/field"
 	kubeschedulerconfig "k8s.io/kubernetes/pkg/scheduler/apis/config"
 	"k8s.io/kubernetes/pkg/scheduler/factory"
 )
@@ -43,7 +44,6 @@ func (o *DeprecatedOptions) AddFlags(fs *pflag.FlagSet, cfg *kubeschedulerconfig
 	}
 
 	// TODO: unify deprecation mechanism, string prefix or MarkDeprecated (the latter hides the flag. We also don't want that).
-
 	fs.StringVar(&o.AlgorithmProvider, "algorithm-provider", o.AlgorithmProvider, "DEPRECATED: the scheduling algorithm provider to use, one of: "+factory.ListAlgorithmProviders())
 	fs.StringVar(&o.PolicyConfigFile, "policy-config-file", o.PolicyConfigFile, "DEPRECATED: file with scheduler policy configuration. This file is used if policy ConfigMap is not provided or --use-legacy-policy-config=true")
 	usage := fmt.Sprintf("DEPRECATED: name of the ConfigMap object that contains scheduler's policy configuration. It must exist in the system namespace before scheduler initialization if --use-legacy-policy-config=false. The config must be provided as the value of an element in 'Data' map with the key='%v'", kubeschedulerconfig.SchedulerPolicyConfigMapKey)
@@ -63,7 +63,7 @@ func (o *DeprecatedOptions) AddFlags(fs *pflag.FlagSet, cfg *kubeschedulerconfig
 
 	fs.Int32Var(&cfg.HardPodAffinitySymmetricWeight, "hard-pod-affinity-symmetric-weight", cfg.HardPodAffinitySymmetricWeight,
 		"RequiredDuringScheduling affinity is not symmetric, but there is an implicit PreferredDuringScheduling affinity rule corresponding "+
-			"to every RequiredDuringScheduling affinity rule. --hard-pod-affinity-symmetric-weight represents the weight of implicit PreferredDuringScheduling affinity rule.")
+			"to every RequiredDuringScheduling affinity rule. --hard-pod-affinity-symmetric-weight represents the weight of implicit PreferredDuringScheduling affinity rule. Must be in the range 0-100.")
 	fs.MarkDeprecated("hard-pod-affinity-symmetric-weight", "This option was moved to the policy configuration file")
 	fs.StringVar(&cfg.FailureDomains, "failure-domains", cfg.FailureDomains, "Indicate the \"all topologies\" set for an empty topologyKey when it's used for PreferredDuringScheduling pod anti-affinity.")
 	fs.MarkDeprecated("failure-domains", "Doesn't have any effect. Will be removed in future version.")
@@ -71,10 +71,12 @@ func (o *DeprecatedOptions) AddFlags(fs *pflag.FlagSet, cfg *kubeschedulerconfig
 
 // Validate validates the deprecated scheduler options.
 func (o *DeprecatedOptions) Validate() []error {
-	if o == nil {
-		return nil
+	var errs []error
+
+	if o.UseLegacyPolicyConfig && len(o.PolicyConfigFile) == 0 {
+		errs = append(errs, field.Required(field.NewPath("policyConfigFile"), "required when --use-legacy-policy-config is true"))
 	}
-	return nil
+	return errs
 }
 
 // ApplyTo sets cfg.AlgorithmSource from flags passed on the command line in the following precedence order:

cmd/kube-scheduler/app/options/deprecated_test.go

@@ -0,0 +1,55 @@
+/*
+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 options
+
+import (
+	"testing"
+)
+
+func TestValidateDeprecatedKubeSchedulerConfiguration(t *testing.T) {
+	scenarios := map[string]struct {
+		expectedToFail bool
+		config         *DeprecatedOptions
+	}{
+		"good": {
+			expectedToFail: false,
+			config: &DeprecatedOptions{
+				PolicyConfigFile:      "/some/file",
+				UseLegacyPolicyConfig: true,
+				AlgorithmProvider:     "",
+			},
+		},
+		"bad-policy-config-file-null": {
+			expectedToFail: true,
+			config: &DeprecatedOptions{
+				PolicyConfigFile:      "",
+				UseLegacyPolicyConfig: true,
+				AlgorithmProvider:     "",
+			},
+		},
+	}
+
+	for name, scenario := range scenarios {
+		errs := scenario.config.Validate()
+		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)
+		}
+	}
+}

cmd/kube-scheduler/app/options/options.go

@@ -47,6 +47,7 @@ import (
 	"k8s.io/kubernetes/pkg/client/leaderelectionconfig"
 	kubeschedulerconfig "k8s.io/kubernetes/pkg/scheduler/apis/config"
 	kubeschedulerscheme "k8s.io/kubernetes/pkg/scheduler/apis/config/scheme"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config/validation"
 	"k8s.io/kubernetes/pkg/scheduler/factory"
 )
 
@@ -185,6 +186,9 @@ func (o *Options) ApplyTo(c *schedulerappconfig.Config) error {
 func (o *Options) Validate() []error {
 	var errs []error
 
+	if err := validation.ValidateKubeSchedulerConfiguration(&o.ComponentConfig).ToAggregate(); err != nil {
+		errs = append(errs, err.Errors()...)
+	}
 	errs = append(errs, o.SecureServing.Validate()...)
 	errs = append(errs, o.CombinedInsecureServing.Validate()...)
 	errs = append(errs, o.Authentication.Validate()...)

pkg/scheduler/apis/config/BUILD

@@ -32,6 +32,7 @@ filegroup(
         ":package-srcs",
         "//pkg/scheduler/apis/config/scheme:all-srcs",
         "//pkg/scheduler/apis/config/v1alpha1:all-srcs",
+        "//pkg/scheduler/apis/config/validation:all-srcs",
     ],
     tags = ["automanaged"],
     visibility = ["//visibility:public"],

pkg/scheduler/apis/config/validation/BUILD

@@ -0,0 +1,41 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["validation.go"],
+    importpath = "k8s.io/kubernetes/pkg/scheduler/apis/config/validation",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/scheduler/apis/config:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/config/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/config/validation:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["validation_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/scheduler/apis/config:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/config:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/config: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"],
+)

pkg/scheduler/apis/config/validation/validation.go

@@ -0,0 +1,61 @@
+/*
+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 (
+	apimachinery "k8s.io/apimachinery/pkg/apis/config/validation"
+	"k8s.io/apimachinery/pkg/util/validation"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	apiserver "k8s.io/apiserver/pkg/apis/config/validation"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+)
+
+// ValidateKubeSchedulerConfiguration ensures validation of the KubeSchedulerConfiguration struct
+func ValidateKubeSchedulerConfiguration(cc *config.KubeSchedulerConfiguration) field.ErrorList {
+	allErrs := field.ErrorList{}
+	allErrs = append(allErrs, apimachinery.ValidateClientConnectionConfiguration(&cc.ClientConnection, field.NewPath("clientConnection"))...)
+	allErrs = append(allErrs, ValidateKubeSchedulerLeaderElectionConfiguration(&cc.LeaderElection, field.NewPath("leaderElection"))...)
+	if len(cc.SchedulerName) == 0 {
+		allErrs = append(allErrs, field.Required(field.NewPath("schedulerName"), ""))
+	}
+	for _, msg := range validation.IsValidSocketAddr(cc.HealthzBindAddress) {
+		allErrs = append(allErrs, field.Invalid(field.NewPath("healthzBindAddress"), cc.HealthzBindAddress, msg))
+	}
+	for _, msg := range validation.IsValidSocketAddr(cc.MetricsBindAddress) {
+		allErrs = append(allErrs, field.Invalid(field.NewPath("metricsBindAddress"), cc.MetricsBindAddress, msg))
+	}
+	if cc.HardPodAffinitySymmetricWeight < 0 || cc.HardPodAffinitySymmetricWeight > 100 {
+		allErrs = append(allErrs, field.Invalid(field.NewPath("hardPodAffinitySymmetricWeight"), cc.HardPodAffinitySymmetricWeight, "not in valid range 0-100"))
+	}
+	return allErrs
+}
+
+// ValidateKubeSchedulerLeaderElectionConfiguration ensures validation of the KubeSchedulerLeaderElectionConfiguration struct
+func ValidateKubeSchedulerLeaderElectionConfiguration(cc *config.KubeSchedulerLeaderElectionConfiguration, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	if !cc.LeaderElectionConfiguration.LeaderElect {
+		return allErrs
+	}
+	allErrs = append(allErrs, apiserver.ValidateLeaderElectionConfiguration(&cc.LeaderElectionConfiguration, field.NewPath("leaderElectionConfiguration"))...)
+	if len(cc.LockObjectNamespace) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("lockObjectNamespace"), ""))
+	}
+	if len(cc.LockObjectName) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("lockObjectName"), ""))
+	}
+	return allErrs
+}

pkg/scheduler/apis/config/validation/validation_test.go

@@ -0,0 +1,140 @@
+/*
+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 (
+	apimachinery "k8s.io/apimachinery/pkg/apis/config"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	apiserver "k8s.io/apiserver/pkg/apis/config"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+	"testing"
+	"time"
+)
+
+func TestValidateKubeSchedulerConfiguration(t *testing.T) {
+	validConfig := &config.KubeSchedulerConfiguration{
+		SchedulerName:                  "me",
+		HealthzBindAddress:             "0.0.0.0:10254",
+		MetricsBindAddress:             "0.0.0.0:10254",
+		HardPodAffinitySymmetricWeight: 80,
+		ClientConnection: apimachinery.ClientConnectionConfiguration{
+			AcceptContentTypes: "application/json",
+			ContentType:        "application/json",
+			QPS:                10,
+			Burst:              10,
+		},
+		AlgorithmSource: config.SchedulerAlgorithmSource{
+			Policy: &config.SchedulerPolicySource{
+				ConfigMap: &config.SchedulerPolicyConfigMapSource{
+					Namespace: "name",
+					Name:      "name",
+				},
+			},
+		},
+		LeaderElection: config.KubeSchedulerLeaderElectionConfiguration{
+			LockObjectNamespace: "name",
+			LockObjectName:      "name",
+			LeaderElectionConfiguration: apiserver.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},
+			},
+		},
+	}
+
+	HardPodAffinitySymmetricWeightGt100 := validConfig.DeepCopy()
+	HardPodAffinitySymmetricWeightGt100.HardPodAffinitySymmetricWeight = 120
+
+	HardPodAffinitySymmetricWeightLt0 := validConfig.DeepCopy()
+	HardPodAffinitySymmetricWeightLt0.HardPodAffinitySymmetricWeight = -1
+
+	lockObjectNameNotSet := validConfig.DeepCopy()
+	lockObjectNameNotSet.LeaderElection.LockObjectName = ""
+
+	lockObjectNamespaceNotSet := validConfig.DeepCopy()
+	lockObjectNamespaceNotSet.LeaderElection.LockObjectNamespace = ""
+
+	metricsBindAddrHostInvalid := validConfig.DeepCopy()
+	metricsBindAddrHostInvalid.MetricsBindAddress = "0.0.0.0.0:9090"
+
+	metricsBindAddrPortInvalid := validConfig.DeepCopy()
+	metricsBindAddrPortInvalid.MetricsBindAddress = "0.0.0.0:909090"
+
+	healthzBindAddrHostInvalid := validConfig.DeepCopy()
+	healthzBindAddrHostInvalid.HealthzBindAddress = "0.0.0.0.0:9090"
+
+	healthzBindAddrPortInvalid := validConfig.DeepCopy()
+	healthzBindAddrPortInvalid.HealthzBindAddress = "0.0.0.0:909090"
+
+	enableContentProfilingSetWithoutEnableProfiling := validConfig.DeepCopy()
+	enableContentProfilingSetWithoutEnableProfiling.EnableProfiling = false
+	enableContentProfilingSetWithoutEnableProfiling.EnableContentionProfiling = true
+
+	scenarios := map[string]struct {
+		expectedToFail bool
+		config         *config.KubeSchedulerConfiguration
+	}{
+		"good": {
+			expectedToFail: false,
+			config:         validConfig,
+		},
+		"bad-lock-object-names-not-set": {
+			expectedToFail: true,
+			config:         lockObjectNameNotSet,
+		},
+		"bad-lock-object-namespace-not-set": {
+			expectedToFail: true,
+			config:         lockObjectNamespaceNotSet,
+		},
+		"bad-healthz-port-invalid": {
+			expectedToFail: true,
+			config:         healthzBindAddrPortInvalid,
+		},
+		"bad-healthz-host-invalid": {
+			expectedToFail: true,
+			config:         healthzBindAddrHostInvalid,
+		},
+		"bad-metrics-port-invalid": {
+			expectedToFail: true,
+			config:         metricsBindAddrPortInvalid,
+		},
+		"bad-metrics-host-invalid": {
+			expectedToFail: true,
+			config:         metricsBindAddrHostInvalid,
+		},
+		"bad-hard-pod-affinity-symmetric-weight-lt-0": {
+			expectedToFail: true,
+			config:         HardPodAffinitySymmetricWeightGt100,
+		},
+		"bad-hard-pod-affinity-symmetric-weight-gt-100": {
+			expectedToFail: true,
+			config:         HardPodAffinitySymmetricWeightLt0,
+		},
+	}
+
+	for name, scenario := range scenarios {
+		errs := ValidateKubeSchedulerConfiguration(scenario.config)
+		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)
+		}
+	}
+}

staging/src/k8s.io/apimachinery/pkg/apis/config/BUILD

@@ -24,6 +24,7 @@ filegroup(
     srcs = [
         ":package-srcs",
         "//staging/src/k8s.io/apimachinery/pkg/apis/config/v1alpha1:all-srcs",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/config/validation:all-srcs",
     ],
     tags = ["automanaged"],
     visibility = ["//visibility:public"],

staging/src/k8s.io/apimachinery/pkg/apis/config/validation/BUILD

@@ -0,0 +1,37 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["validation.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/apis/config/validation",
+    importpath = "k8s.io/apimachinery/pkg/apis/config/validation",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/apis/config:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["validation_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/apis/config:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field: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"],
+)

staging/src/k8s.io/apimachinery/pkg/apis/config/validation/validation.go

@@ -0,0 +1,31 @@
+/*
+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/apis/config"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+)
+
+// ValidateClientConnectionConfiguration ensures validation of the ClientConnectionConfiguration struct
+func ValidateClientConnectionConfiguration(cc *config.ClientConnectionConfiguration, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	if cc.Burst < 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("burst"), cc.Burst, "must be non-negative"))
+	}
+	return allErrs
+}

staging/src/k8s.io/apimachinery/pkg/apis/config/validation/validation_test.go

@@ -0,0 +1,66 @@
+/*
+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/apis/config"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"testing"
+)
+
+func TestValidateClientConnectionConfiguration(t *testing.T) {
+	validConfig := &config.ClientConnectionConfiguration{
+		AcceptContentTypes: "application/json",
+		ContentType:        "application/json",
+		QPS:                10,
+		Burst:              10,
+	}
+
+	qpsLessThanZero := validConfig.DeepCopy()
+	qpsLessThanZero.QPS = -1
+
+	burstLessThanZero := validConfig.DeepCopy()
+	burstLessThanZero.Burst = -1
+
+	scenarios := map[string]struct {
+		expectedToFail bool
+		config         *config.ClientConnectionConfiguration
+	}{
+		"good": {
+			expectedToFail: false,
+			config:         validConfig,
+		},
+		"good-qps-less-than-zero": {
+			expectedToFail: false,
+			config:         qpsLessThanZero,
+		},
+		"bad-burst-less-then-zero": {
+			expectedToFail: true,
+			config:         burstLessThanZero,
+		},
+	}
+
+	for name, scenario := range scenarios {
+		errs := ValidateClientConnectionConfiguration(scenario.config, field.NewPath("clientConnectionConfiguration"))
+		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)
+		}
+	}
+}

staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go

@@ -21,6 +21,7 @@ import (
 	"math"
 	"net"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/util/validation/field"
@@ -389,3 +390,18 @@ func hasChDirPrefix(value string) []string {
 	}
 	return errs
 }
+
+// IsSocketAddr checks that a string conforms is a valid socket address
+// as defined in RFC 789. (e.g 0.0.0.0:10254 or [::]:10254))
+func IsValidSocketAddr(value string) []string {
+	var errs []string
+	ip, port, err := net.SplitHostPort(value)
+	if err != nil {
+		return append(errs, "must be a valid socket address format, (e.g. 0.0.0.0:10254 or [::]:10254)")
+		return errs
+	}
+	portInt, _ := strconv.Atoi(port)
+	errs = append(errs, IsValidPortNum(portInt)...)
+	errs = append(errs, IsValidIP(ip)...)
+	return errs
+}

staging/src/k8s.io/apimachinery/pkg/util/validation/validation_test.go

@@ -511,3 +511,31 @@ func TestIsFullyQualifiedName(t *testing.T) {
 		}
 	}
 }
+
+func TestIsValidSocketAddr(t *testing.T) {
+	goodValues := []string{
+		"0.0.0.0:10254",
+		"127.0.0.1:8888",
+		"[2001:db8:1f70::999:de8:7648:6e8]:10254",
+		"[::]:10254",
+	}
+	for _, val := range goodValues {
+		if errs := IsValidSocketAddr(val); len(errs) != 0 {
+			t.Errorf("expected no errors for %q: %v", val, errs)
+		}
+	}
+
+	badValues := []string{
+		"0.0.0.0.0:2020",
+		"0.0.0.0",
+		"6.6.6.6:909090",
+		"2001:db8:1f70::999:de8:7648:6e8:87567:102545",
+		"",
+		"*",
+	}
+	for _, val := range badValues {
+		if errs := IsValidSocketAddr(val); len(errs) == 0 {
+			t.Errorf("expected errors for %q", val)
+		}
+	}
+}

staging/src/k8s.io/apiserver/pkg/apis/config/BUILD

@@ -25,6 +25,7 @@ filegroup(
     srcs = [
         ":package-srcs",
         "//staging/src/k8s.io/apiserver/pkg/apis/config/v1alpha1:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/apis/config/validation:all-srcs",
     ],
     tags = ["automanaged"],
     visibility = ["//visibility:public"],

staging/src/k8s.io/apiserver/pkg/apis/config/validation/BUILD

@@ -0,0 +1,38 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["validation.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/apis/config/validation",
+    importpath = "k8s.io/apiserver/pkg/apis/config/validation",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/config:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["validation_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/config: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"],
+)

staging/src/k8s.io/apiserver/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
+}

staging/src/k8s.io/apiserver/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)
+		}
+	}
+}