migrate EvenPodsSpread Predicate to Filter plugin

Author: Huang-Wei

pkg/scheduler/framework/plugins/BUILD

@@ -18,6 +18,7 @@ go_library(
         "//pkg/scheduler/framework/plugins/nodepreferavoidpods:go_default_library",
         "//pkg/scheduler/framework/plugins/noderesources:go_default_library",
         "//pkg/scheduler/framework/plugins/nodevolumelimits:go_default_library",
+        "//pkg/scheduler/framework/plugins/podtopologyspread:go_default_library",
         "//pkg/scheduler/framework/plugins/tainttoleration:go_default_library",
         "//pkg/scheduler/framework/plugins/volumebinding:go_default_library",
         "//pkg/scheduler/framework/plugins/volumerestrictions:go_default_library",
@@ -52,6 +53,7 @@ filegroup(
         "//pkg/scheduler/framework/plugins/nodepreferavoidpods:all-srcs",
         "//pkg/scheduler/framework/plugins/noderesources:all-srcs",
         "//pkg/scheduler/framework/plugins/nodevolumelimits:all-srcs",
+        "//pkg/scheduler/framework/plugins/podtopologyspread:all-srcs",
         "//pkg/scheduler/framework/plugins/tainttoleration:all-srcs",
         "//pkg/scheduler/framework/plugins/volumebinding:all-srcs",
         "//pkg/scheduler/framework/plugins/volumerestrictions:all-srcs",

pkg/scheduler/framework/plugins/default_registry.go

@@ -34,6 +34,7 @@ import (
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/nodepreferavoidpods"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/noderesources"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/nodevolumelimits"
+	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/podtopologyspread"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/tainttoleration"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumerestrictions"
@@ -73,6 +74,7 @@ func NewDefaultRegistry(args *RegistryArgs) framework.Registry {
 		nodeports.Name:           nodeports.New,
 		nodepreferavoidpods.Name: nodepreferavoidpods.New,
 		nodeaffinity.Name:        nodeaffinity.New,
+		podtopologyspread.Name:   podtopologyspread.New,
 		volumebinding.Name: func(_ *runtime.Unknown, _ framework.FrameworkHandle) (framework.Plugin, error) {
 			return volumebinding.NewFromVolumeBinder(args.VolumeBinder), nil
 		},
@@ -113,6 +115,7 @@ func NewDefaultConfigProducerRegistry() *ConfigProducerRegistry {
 		PredicateToConfigProducer: make(map[string]ConfigProducer),
 		PriorityToConfigProducer:  make(map[string]ConfigProducer),
 	}
+	// Register Predicates.
 	registry.RegisterPredicate(predicates.GeneralPred,
 		func(_ ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			// GeneralPredicate is a combination of predicates.
@@ -172,25 +175,27 @@ func NewDefaultConfigProducerRegistry() *ConfigProducerRegistry {
 			plugins.Filter = appendToPluginSet(plugins.Filter, interpodaffinity.Name, nil)
 			return
 		})
-
+	registry.RegisterPredicate(predicates.EvenPodsSpreadPred,
+		func(_ ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
+			plugins.Filter = appendToPluginSet(plugins.Filter, podtopologyspread.Name, nil)
+			return
+		})
+	// Register Priorities.
 	registry.RegisterPriority(priorities.TaintTolerationPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, tainttoleration.Name, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.NodeAffinityPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, nodeaffinity.Name, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.ImageLocalityPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, imagelocality.Name, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.NodePreferAvoidPodsPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, nodepreferavoidpods.Name, &args.Weight)

pkg/scheduler/framework/plugins/podtopologyspread/BUILD

@@ -0,0 +1,44 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["pod_topology_spread.go"],
+    importpath = "k8s.io/kubernetes/pkg/scheduler/framework/plugins/podtopologyspread",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/scheduler/algorithm/predicates:go_default_library",
+        "//pkg/scheduler/framework/plugins/migration:go_default_library",
+        "//pkg/scheduler/framework/v1alpha1:go_default_library",
+        "//pkg/scheduler/nodeinfo:go_default_library",
+        "//staging/src/k8s.io/api/core/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["pod_topology_spread_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/scheduler/algorithm/predicates:go_default_library",
+        "//pkg/scheduler/framework/plugins/migration:go_default_library",
+        "//pkg/scheduler/framework/v1alpha1:go_default_library",
+        "//pkg/scheduler/nodeinfo:go_default_library",
+        "//pkg/scheduler/testing:go_default_library",
+        "//staging/src/k8s.io/api/core/v1: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/framework/plugins/podtopologyspread/pod_topology_spread.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2019 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 podtopologyspread
+
+import (
+	"context"
+	"fmt"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kubernetes/pkg/scheduler/algorithm/predicates"
+	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/migration"
+	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
+)
+
+// PodTopologySpread is a plugin that ensures pod's topologySpreadConstraints is satisfied.
+type PodTopologySpread struct{}
+
+var _ framework.FilterPlugin = &PodTopologySpread{}
+
+// Name is the name of the plugin used in the plugin registry and configurations.
+const Name = "PodTopologySpread"
+
+// Name returns name of the plugin. It is used in logs, etc.
+func (pl *PodTopologySpread) Name() string {
+	return Name
+}
+
+// Filter invoked at the filter extension point.
+func (pl *PodTopologySpread) Filter(ctx context.Context, cycleState *framework.CycleState, pod *v1.Pod, nodeInfo *nodeinfo.NodeInfo) *framework.Status {
+	meta, ok := migration.PredicateMetadata(cycleState).(predicates.PredicateMetadata)
+	if !ok {
+		return migration.ErrorToFrameworkStatus(fmt.Errorf("%+v convert to predicates.PredicateMetadata error", cycleState))
+	}
+	_, reasons, err := predicates.EvenPodsSpreadPredicate(pod, meta, nodeInfo)
+	return migration.PredicateResultToFrameworkStatus(reasons, err)
+}
+
+// New initializes a new plugin and returns it.
+func New(_ *runtime.Unknown, _ framework.FrameworkHandle) (framework.Plugin, error) {
+	return &PodTopologySpread{}, nil
+}