refactor scheduler factory to use plugin architecture style like…

cmd/integration/integration.go

@@ -169,7 +169,7 @@ func startComponents(manifestURL string) (apiServerURL string) {
 
 	// Scheduler
 	schedulerConfigFactory := factory.NewConfigFactory(cl)
-	schedulerConfig, err := schedulerConfigFactory.Create(nil, nil)
+	schedulerConfig, err := schedulerConfigFactory.Create()
 	if err != nil {
 		glog.Fatal("Couldn't create scheduler config: %v", err)
 	}

pkg/standalone/standalone.go

@@ -38,6 +38,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler"
+	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/algorithmprovider"
 	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"
 
 	"github.com/golang/glog"
@@ -105,7 +106,7 @@ func RunApiServer(cl *client.Client, etcdClient tools.EtcdClient, addr string, p
 func RunScheduler(cl *client.Client) {
 	// Scheduler
 	schedulerConfigFactory := factory.NewConfigFactory(cl)
-	schedulerConfig, err := schedulerConfigFactory.Create(nil, nil)
+	schedulerConfig, err := schedulerConfigFactory.Create()
 	if err != nil {
 		glog.Fatal("Couldn't create scheduler config: %v", err)
 	}

plugin/cmd/kube-scheduler/scheduler.go

@@ -29,6 +29,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/version/verflag"
 	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler"
+	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/algorithmprovider"
 	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"
 	"github.com/golang/glog"
 )
@@ -61,7 +62,7 @@ func main() {
 	go http.ListenAndServe(net.JoinHostPort(address.String(), strconv.Itoa(*port)), nil)
 
 	configFactory := factory.NewConfigFactory(kubeClient)
-	config, err := configFactory.Create(nil, nil)
+	config, err := configFactory.Create()
 	if err != nil {
 		glog.Fatalf("Failed to create scheduler configuration: %v", err)
 	}

plugin/pkg/scheduler/algorithmprovider/defaults/defaults.go

+/*
+Copyright 2014 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.
+*/
+
+// This is the default algorithm provider for the scheduler.
+package defaults
+
+import (
+	algorithm "github.com/GoogleCloudPlatform/kubernetes/pkg/scheduler"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"
+)
+
+func init() {
+	factory.RegisterAlgorithmProvider(factory.DefaultProvider, defaultPredicates(), defaultPriorities())
+}
+
+func defaultPredicates() util.StringSet {
+	return util.NewStringSet(
+		// Fit is defined based on the absence of port conflicts.
+		factory.RegisterFitPredicate("PodFitsPorts", algorithm.PodFitsPorts),
+		// Fit is determined by resource availability
+		factory.RegisterFitPredicate("PodFitsResources", algorithm.NewResourceFitPredicate(factory.MinionLister)),
+		// Fit is determined by non-conflicting disk volumes
+		factory.RegisterFitPredicate("NoDiskConflict", algorithm.NoDiskConflict),
+		// Fit is determined by node selector query
+		factory.RegisterFitPredicate("MatchNodeSelector", algorithm.NewSelectorMatchPredicate(factory.MinionLister)),
+	)
+}
+
+func defaultPriorities() util.StringSet {
+	return util.NewStringSet(
+		// Prioritize nodes by least requested utilization.
+		factory.RegisterPriorityFunction("LeastRequestedPriority", algorithm.LeastRequestedPriority, 1),
+		// spreads pods by minimizing the number of pods on the same minion with the same labels.
+		factory.RegisterPriorityFunction("SpreadingPriority", algorithm.CalculateSpreadPriority, 1),
+		// EqualPriority is a prioritizer function that gives an equal weight of one to all minions
+		factory.RegisterPriorityFunction("EqualPriority", algorithm.EqualPriority, 0),
+	)
+}

plugin/pkg/scheduler/algorithmprovider/plugins.go

+/*
+Copyright 2014 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.
+*/
+
+// This package is used to register algorithm provider plugins.
+package algorithmprovider
+
+import (
+	_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/algorithmprovider/defaults"
+)

plugin/pkg/scheduler/algorithmprovider/plugins_test.go

+/*
+Copyright 2014 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 algorithmprovider
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"
+)
+
+var (
+	algorithmProviderNames = []string{
+		factory.DefaultProvider,
+	}
+)
+
+func TestDefaultConfigExists(t *testing.T) {
+	p, err := factory.GetAlgorithmProvider(factory.DefaultProvider)
+	if err != nil {
+		t.Errorf("error retrivieving default provider: %v", err)
+	}
+	if p == nil {
+		t.Error("algorithm provider config should not be nil")
+	}
+	if len(p.FitPredicateKeys) == 0 {
+		t.Error("default algorithm provider shouldn't have 0 fit predicates")
+	}
+}
+
+func TestAlgorithmProviders(t *testing.T) {
+	for _, pn := range algorithmProviderNames {
+		p, err := factory.GetAlgorithmProvider(pn)
+		if err != nil {
+			t.Errorf("error retrivieving '%s' provider: %v", pn, err)
+			break
+		}
+		if len(p.PriorityFunctionKeys) == 0 {
+			t.Error("%s algorithm provider shouldn't have 0 priority functions", pn)
+		}
+		for _, pf := range p.PriorityFunctionKeys.List() {
+			if !factory.IsPriorityFunctionRegistered(pf) {
+				t.Errorf("priority function %s is not registerd but is used in the %s algorithm provider", pf, pn)
+			}
+		}
+		for _, fp := range p.FitPredicateKeys.List() {
+			if !factory.IsFitPredicateRegistered(fp) {
+				t.Errorf("fit predicate %s is not registerd but is used in the %s algorithm provider", fp, pn)
+			}
+		}
+	}
+}

plugin/pkg/scheduler/factory/factory.go

@@ -37,6 +37,11 @@ import (
 	"github.com/golang/glog"
 )
 
+var (
+	PodLister    = &storeToPodLister{cache.NewStore()}
+	MinionLister = &storeToNodeLister{cache.NewStore()}
+)
+
 // ConfigFactory knows how to fill out a scheduler config with its support functions.
 type ConfigFactory struct {
 	Client *client.Client
@@ -46,71 +51,66 @@ type ConfigFactory struct {
 	PodLister *storeToPodLister
 	// a means to list all minions
 	MinionLister *storeToNodeLister
-	// map of strings to predicate functions to be used
-	// to filter the minions for scheduling pods
-	PredicateMap map[string]algorithm.FitPredicate
-	// map of strings to priority config to be used
-	// to prioritize the filtered minions for scheduling pods
-	PriorityMap map[string]algorithm.PriorityConfig
 }
 
 // NewConfigFactory initializes the factory.
 func NewConfigFactory(client *client.Client) *ConfigFactory {
-	// initialize the factory struct
-	factory := &ConfigFactory{
+	return &ConfigFactory{
 		Client:       client,
 		PodQueue:     cache.NewFIFO(),
-		PodLister:    &storeToPodLister{cache.NewStore()},
-		MinionLister: &storeToNodeLister{cache.NewStore()},
-		PredicateMap: make(map[string]algorithm.FitPredicate),
-		PriorityMap:  make(map[string]algorithm.PriorityConfig),
+		PodLister:    PodLister,
+		MinionLister: MinionLister,
 	}
+}
 
-	factory.addDefaultPredicates()
-	factory.addDefaultPriorities()
-
-	return factory
+// Create creates a scheduler with the default algorithm provider.
+func (f *ConfigFactory) Create() (*scheduler.Config, error) {
+	return f.CreateFromProvider(DefaultProvider)
 }
 
-// Create creates a scheduler and all support functions.
-func (factory *ConfigFactory) Create(predicateKeys, priorityKeys []string) (*scheduler.Config, error) {
-	if predicateKeys == nil {
-		glog.V(2).Infof("Custom predicates list not provided, using default predicates")
-		predicateKeys = []string{"PodFitsPorts", "PodFitsResources", "NoDiskConflict", "MatchNodeSelector"}
-	}
-	predicateFuncs, err := factory.getPredicateFunctions(predicateKeys)
+// CreateFromProvider creates a scheduler from the name of a registered algorithm provider.
+func (f *ConfigFactory) CreateFromProvider(providerName string) (*scheduler.Config, error) {
+	glog.V(2).Infof("creating scheduler from algorithm provider '%v'", providerName)
+	provider, err := GetAlgorithmProvider(providerName)
 	if err != nil {
 		return nil, err
 	}
 
-	if priorityKeys == nil {
-		glog.V(2).Infof("Custom priority list not provided, using default priority: LeastRequestedPriority")
-		priorityKeys = []string{"LeastRequestedPriority"}
+	return f.CreateFromKeys(provider.FitPredicateKeys, provider.PriorityFunctionKeys)
+}
+
+// CreateFromKeys creates a scheduler from a set of registered fit predicate keys and priority keys.
+func (f *ConfigFactory) CreateFromKeys(predicateKeys, priorityKeys util.StringSet) (*scheduler.Config, error) {
+	glog.V(2).Infof("creating scheduler with fit predicates '%v' and priority functions '%v", predicateKeys, priorityKeys)
+	predicateFuncs, err := getFitPredicateFunctions(predicateKeys)
+	if err != nil {
+		return nil, err
 	}
-	priorityConfigs, err := factory.getPriorityConfigs(priorityKeys)
+
+	priorityConfigs, err := getPriorityFunctionConfigs(priorityKeys)
 	if err != nil {
 		return nil, err
 	}
 
 	// Watch and queue pods that need scheduling.
-	cache.NewReflector(factory.createUnassignedPodLW(), &api.Pod{}, factory.PodQueue).Run()
+	cache.NewReflector(f.createUnassignedPodLW(), &api.Pod{}, f.PodQueue).Run()
 
 	// Watch and cache all running pods. Scheduler needs to find all pods
 	// so it knows where it's safe to place a pod. Cache this locally.
-	cache.NewReflector(factory.createAssignedPodLW(), &api.Pod{}, factory.PodLister.Store).Run()
+	cache.NewReflector(f.createAssignedPodLW(), &api.Pod{}, f.PodLister.Store).Run()
 
 	// Watch minions.
 	// Minions may be listed frequently, so provide a local up-to-date cache.
 	if false {
 		// Disable this code until minions support watches.
-		cache.NewReflector(factory.createMinionLW(), &api.Node{}, factory.MinionLister.Store).Run()
+		cache.NewReflector(f.createMinionLW(), &api.Node{}, f.MinionLister.Store).Run()
 	} else {
-		cache.NewPoller(factory.pollMinions, 10*time.Second, factory.MinionLister.Store).Run()
+		cache.NewPoller(f.pollMinions, 10*time.Second, f.MinionLister.Store).Run()
 	}
 
 	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 
-	algo := algorithm.NewGenericScheduler(predicateFuncs, priorityConfigs, factory.PodLister, r)
+	algo := algorithm.NewGenericScheduler(predicateFuncs, priorityConfigs, f.PodLister, r)
 
 	podBackoff := podBackoff{
 		perPodBackoff: map[string]*backoffEntry{},
@@ -118,79 +118,18 @@ func (factory *ConfigFactory) Create(predicateKeys, priorityKeys []string) (*sch
 	}
 
 	return &scheduler.Config{
-		MinionLister: factory.MinionLister,
+		MinionLister: f.MinionLister,
 		Algorithm:    algo,
-		Binder:       &binder{factory.Client},
+		Binder:       &binder{f.Client},
 		NextPod: func() *api.Pod {
-			pod := factory.PodQueue.Pop().(*api.Pod)
+			pod := f.PodQueue.Pop().(*api.Pod)
 			glog.V(2).Infof("glog.v2 --> About to try and schedule pod %v", pod.Name)
 			return pod
 		},
-		Error: factory.makeDefaultErrorFunc(&podBackoff, factory.PodQueue),
+		Error: f.makeDefaultErrorFunc(&podBackoff, f.PodQueue),
 	}, nil
 }
 
-func (factory *ConfigFactory) getPredicateFunctions(keys []string) ([]algorithm.FitPredicate, error) {
-	predicates := []algorithm.FitPredicate{}
-	for _, key := range keys {
-		function, ok := factory.PredicateMap[key]
-		if !ok {
-			return nil, fmt.Errorf("Invalid predicate key %s specified - no corresponding function found", key)
-		}
-		predicates = append(predicates, function)
-	}
-	return predicates, nil
-}
-
-func (factory *ConfigFactory) getPriorityConfigs(keys []string) ([]algorithm.PriorityConfig, error) {
-	configs := []algorithm.PriorityConfig{}
-	for _, key := range keys {
-		config, ok := factory.PriorityMap[key]
-		if !ok {
-			return nil, fmt.Errorf("Invalid priority key %s specified - no corresponding function found", key)
-		}
-		configs = append(configs, config)
-	}
-	return configs, nil
-}
-
-func (factory *ConfigFactory) addDefaultPredicates() {
-	// Fit is defined based on the absence of port conflicts.
-	factory.AddPredicate("PodFitsPorts", algorithm.PodFitsPorts)
-	// Fit is determined by resource availability
-	factory.AddPredicate("PodFitsResources", algorithm.NewResourceFitPredicate(factory.MinionLister))
-	// Fit is determined by non-conflicting disk volumes
-	factory.AddPredicate("NoDiskConflict", algorithm.NoDiskConflict)
-	// Fit is determined by node selector query
-	factory.AddPredicate("MatchNodeSelector", algorithm.NewSelectorMatchPredicate(factory.MinionLister))
-}
-
-func (factory *ConfigFactory) AddPredicate(key string, function algorithm.FitPredicate) {
-	factory.PredicateMap[key] = function
-}
-
-func (factory *ConfigFactory) addDefaultPriorities() {
-	// Prioritize nodes by least requested utilization.
-	factory.AddPriority("LeastRequestedPriority", algorithm.LeastRequestedPriority, 1)
-	// spreads pods by minimizing the number of pods on the same minion with the same labels.
-	factory.AddPriority("SpreadingPriority", algorithm.CalculateSpreadPriority, 1)
-	// EqualPriority is a prioritizer function that gives an equal weight of one to all minions
-	factory.AddPriority("EqualPriority", algorithm.EqualPriority, 0)
-}
-
-func (factory *ConfigFactory) AddPriority(key string, function algorithm.PriorityFunction, weight int) {
-	factory.PriorityMap[key] = algorithm.PriorityConfig{Function: function, Weight: weight}
-}
-
-func (factory *ConfigFactory) SetWeight(key string, weight int) {
-	config, ok := factory.PriorityMap[key]
-	if !ok {
-		glog.Errorf("Invalid priority key %s specified - no corresponding function found", key)
-		return
-	}
-	config.Weight = weight
-}
-
 type listWatch struct {
 	client        *client.Client
 	fieldSelector labels.Selector

plugin/pkg/scheduler/factory/factory_test.go

@@ -43,7 +43,7 @@ func TestCreate(t *testing.T) {
 	defer server.Close()
 	client := client.NewOrDie(&client.Config{Host: server.URL, Version: testapi.Version()})
 	factory := NewConfigFactory(client)
-	factory.Create(nil, nil)
+	factory.Create()
 }
 
 func TestCreateLists(t *testing.T) {

plugin/pkg/scheduler/factory/plugins.go

+/*
+Copyright 2014 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 factory
+
+import (
+	"fmt"
+	"sync"
+
+	algorithm "github.com/GoogleCloudPlatform/kubernetes/pkg/scheduler"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+
+	"github.com/golang/glog"
+)
+
+var (
+	schedulerFactoryMutex sync.Mutex
+
+	// maps that hold registered algorithm types
+	fitPredicateMap      = make(map[string]algorithm.FitPredicate)
+	priorityFunctionMap  = make(map[string]algorithm.PriorityConfig)
+	algorithmProviderMap = make(map[string]AlgorithmProviderConfig)
+)
+
+const (
+	DefaultProvider = "default"
+)
+
+type AlgorithmProviderConfig struct {
+	FitPredicateKeys     util.StringSet
+	PriorityFunctionKeys util.StringSet
+}
+
+// RegisterFitPredicate registers a fit predicate with the algorithm registry. Returns the key,
+// with which the predicate was registered.
+func RegisterFitPredicate(key string, predicate algorithm.FitPredicate) string {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	fitPredicateMap[key] = predicate
+	return key
+}
+
+// IsFitPredicateRegistered check is useful for testing providers.
+func IsFitPredicateRegistered(key string) bool {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	_, ok := fitPredicateMap[key]
+	return ok
+}
+
+// RegisterFitPredicate registers a priority function with the algorithm registry. Returns the key,
+// with which the function was registered.
+func RegisterPriorityFunction(key string, function algorithm.PriorityFunction, weight int) string {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	priorityFunctionMap[key] = algorithm.PriorityConfig{Function: function, Weight: weight}
+	return key
+}
+
+// IsPriorityFunctionRegistered check is useful for testing providers.
+func IsPriorityFunctionRegistered(key string) bool {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	_, ok := priorityFunctionMap[key]
+	return ok
+}
+
+// SetPriorityFunctionWeight sets the weight of an already registered priority function.
+func SetPriorityFunctionWeight(key string, weight int) {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	config, ok := priorityFunctionMap[key]
+	if !ok {
+		glog.Errorf("Invalid priority key %s specified - no corresponding function found", key)
+		return
+	}
+	config.Weight = weight
+}
+
+// RegisterAlgorithmProvider registers a new algorithm provider with the algorithm registry. This should
+// be called from the init function in a provider plugin.
+func RegisterAlgorithmProvider(name string, predicateKeys, priorityKeys util.StringSet) string {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+	algorithmProviderMap[name] = AlgorithmProviderConfig{
+		FitPredicateKeys:     predicateKeys,
+		PriorityFunctionKeys: priorityKeys,
+	}
+	return name
+}
+
+// GetAlgorithmProvider should not be used to modify providers. It is publicly visible for testing.
+func GetAlgorithmProvider(name string) (*AlgorithmProviderConfig, error) {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+
+	var provider AlgorithmProviderConfig
+	provider, ok := algorithmProviderMap[name]
+	if !ok {
+		return nil, fmt.Errorf("plugin '%v' has not been registered", provider)
+	}
+
+	return &provider, nil
+}
+
+func getFitPredicateFunctions(keys util.StringSet) ([]algorithm.FitPredicate, error) {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+
+	predicates := []algorithm.FitPredicate{}
+	for _, key := range keys.List() {
+		function, ok := fitPredicateMap[key]
+		if !ok {
+			return nil, fmt.Errorf("Invalid predicate key %s specified - no corresponding function found", key)
+		}
+		predicates = append(predicates, function)
+	}
+	return predicates, nil
+}
+
+func getPriorityFunctionConfigs(keys util.StringSet) ([]algorithm.PriorityConfig, error) {
+	schedulerFactoryMutex.Lock()
+	defer schedulerFactoryMutex.Unlock()
+
+	configs := []algorithm.PriorityConfig{}
+	for _, key := range keys.List() {
+		config, ok := priorityFunctionMap[key]
+		if !ok {
+			return nil, fmt.Errorf("Invalid priority key %s specified - no corresponding function found", key)
+		}
+		configs = append(configs, config)
+	}
+	return configs, nil
+}