refactor scheduler factory to use plugin architecture style like credentialprovider and cloudprovider for configuring priority functions and fit predicates

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

@@ -0,0 +1,52 @@
+/*
+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

@@ -0,0 +1,22 @@
+/*
+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

@@ -0,0 +1,65 @@
+/*
+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)
+			}
+		}
+	}
+}