Adding validations for scheduler Policy

plugin/pkg/scheduler/api/types.go

@@ -43,6 +43,7 @@ type PriorityPolicy struct {
 	// For the Kubernetes provided priority functions, the name is the identifier of the pre-defined priority function
 	Name string `json:"name"`
 	// The numeric multiplier for the minion scores that the priority function generates
+	// The weight should be non-zero and can be a positive or a negative integer
 	Weight int `json:"weight"`
 	// Holds the parameters to configure the given priority function
 	Argument *PriorityArgument `json:"argument"`

plugin/pkg/scheduler/api/v1/types.go

@@ -43,6 +43,7 @@ type PriorityPolicy struct {
 	// For the Kubernetes provided priority functions, the name is the identifier of the pre-defined priority function
 	Name string `json:"name"`
 	// The numeric multiplier for the minion scores that the priority function generates
+	// The weight should be non-zero and can be a positive or a negative integer
 	Weight int `json:"weight"`
 	// Holds the parameters to configure the given priority function
 	Argument *PriorityArgument `json:"argument"`

plugin/pkg/scheduler/api/validation/validation.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2015 Google Inc. 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 validation
+
+import (
+	"fmt"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/errors"
+	schedulerapi "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/api"
+)
+
+// Validate checks for errors in the Config
+// It does not return early so that it can find as many errors as possible
+func ValidatePolicy(policy schedulerapi.Policy) error {
+	validationErrors := make([]error, 0)
+
+	for _, priority := range policy.Priorities {
+		if priority.Weight == 0 {
+			validationErrors = append(validationErrors, fmt.Errorf("Priority %s should have a non-zero weight applied to it", priority.Name))
+		}
+	}
+
+	return errors.NewAggregate(validationErrors)
+}

plugin/pkg/scheduler/api/validation/validation_test.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2015 Google Inc. 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 validation
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/api"
+)
+
+func TestValidatePriorityWithNoWeight(t *testing.T) {
+	policy := api.Policy{Priorities: []api.PriorityPolicy{{Name: "NoWeightPriority"}}}
+	if ValidatePolicy(policy) == nil {
+		t.Errorf("Expected error about priority weight being zero")
+	}
+}
+
+func TestValidatePriorityWithZeroWeight(t *testing.T) {
+	policy := api.Policy{Priorities: []api.PriorityPolicy{{Name: "NoWeightPriority", Weight: 0}}}
+	if ValidatePolicy(policy) == nil {
+		t.Errorf("Expected error about priority weight being zero")
+	}
+}
+
+func TestValidatePriorityWithNonZeroWeight(t *testing.T) {
+	policy := api.Policy{Priorities: []api.PriorityPolicy{{Name: "WeightPriority", Weight: 2}}}
+	errs := ValidatePolicy(policy)
+	if ValidatePolicy(policy) != nil {
+		t.Errorf("Unexpected errors %v", errs)
+	}
+}
+
+func TestValidatePriorityWithNegativeWeight(t *testing.T) {
+	policy := api.Policy{Priorities: []api.PriorityPolicy{{Name: "WeightPriority", Weight: -2}}}
+	errs := ValidatePolicy(policy)
+	if ValidatePolicy(policy) != nil {
+		t.Errorf("Unexpected errors %v", errs)
+	}
+}

plugin/pkg/scheduler/factory/factory.go

@@ -31,6 +31,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler"
 	schedulerapi "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/api"
+	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/api/validation"
 
 	"github.com/golang/glog"
 )
@@ -87,6 +88,11 @@ func (f *ConfigFactory) CreateFromProvider(providerName string) (*scheduler.Conf
 func (f *ConfigFactory) CreateFromConfig(policy schedulerapi.Policy) (*scheduler.Config, error) {
 	glog.V(2).Infof("creating scheduler from configuration: %v", policy)
 
+	// validate the policy configuration
+	if err := validation.ValidatePolicy(policy); err != nil {
+		return nil, err
+	}
+
 	predicateKeys := util.NewStringSet()
 	for _, predicate := range policy.Predicates {
 		glog.V(2).Infof("Registering predicate: %s", predicate.Name)