Implement default queue sort logic as a scheduler plugin

pkg/scheduler/framework/plugins/queuesort/BUILD

@@ -0,0 +1,37 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["priority_sort.go"],
+    importpath = "k8s.io/kubernetes/pkg/scheduler/framework/plugins/queuesort",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/api/v1/pod:go_default_library",
+        "//pkg/scheduler/framework/v1alpha1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["priority_sort_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//pkg/scheduler/framework/v1alpha1: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/queuesort/priority_sort.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2020 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 queuesort
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kubernetes/pkg/api/v1/pod"
+	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+)
+
+// Name is the name of the plugin used in the plugin registry and configurations.
+const Name = "PrioritySort"
+
+// PrioritySort is a plugin that implements Priority based sorting.
+type PrioritySort struct{}
+
+var _ framework.QueueSortPlugin = &PrioritySort{}
+
+// Name returns name of the plugin.
+func (pl *PrioritySort) Name() string {
+	return Name
+}
+
+// Less is the function used by the activeQ heap algorithm to sort pods.
+// It sorts pods based on their priority. When priorities are equal, it uses
+// PodInfo.timestamp.
+func (pl *PrioritySort) Less(pInfo1, pInfo2 *framework.PodInfo) bool {
+	p1 := pod.GetPodPriority(pInfo1.Pod)
+	p2 := pod.GetPodPriority(pInfo2.Pod)
+	return (p1 > p2) || (p1 == p2 && pInfo1.Timestamp.Before(pInfo2.Timestamp))
+}
+
+// New initializes a new plugin and returns it.
+func New(plArgs *runtime.Unknown, handle framework.FrameworkHandle) (framework.Plugin, error) {
+	return &PrioritySort{}, nil
+}

pkg/scheduler/framework/plugins/queuesort/priority_sort_test.go

@@ -0,0 +1,121 @@
+/*
+Copyright 2020 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 queuesort
+
+import (
+	"testing"
+	"time"
+
+	v1 "k8s.io/api/core/v1"
+	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+)
+
+func TestLess(t *testing.T) {
+	prioritySort := &PrioritySort{}
+	var lowPriority, highPriority = int32(10), int32(100)
+	t1 := time.Now()
+	t2 := t1.Add(time.Second)
+	for _, tt := range []struct {
+		name     string
+		p1       *framework.PodInfo
+		p2       *framework.PodInfo
+		expected bool
+	}{
+		{
+			name: "p1.priority less than p2.priority",
+			p1: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &lowPriority,
+					},
+				},
+			},
+			p2: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+			},
+			expected: false, // p2 should be ahead of p1 in the queue
+		},
+		{
+			name: "p1.priority greater than p2.priority",
+			p1: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+			},
+			p2: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &lowPriority,
+					},
+				},
+			},
+			expected: true, // p1 should be ahead of p2 in the queue
+		},
+		{
+			name: "equal priority. p1 is added to schedulingQ earlier than p2",
+			p1: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+				Timestamp: t1,
+			},
+			p2: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+				Timestamp: t2,
+			},
+			expected: true, // p1 should be ahead of p2 in the queue
+		},
+		{
+			name: "equal priority. p2 is added to schedulingQ earlier than p1",
+			p1: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+				Timestamp: t2,
+			},
+			p2: &framework.PodInfo{
+				Pod: &v1.Pod{
+					Spec: v1.PodSpec{
+						Priority: &highPriority,
+					},
+				},
+				Timestamp: t1,
+			},
+			expected: false, // p2 should be ahead of p1 in the queue
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := prioritySort.Less(tt.p1, tt.p2); got != tt.expected {
+				t.Errorf("expected %v, got %v", tt.expected, got)
+			}
+		})
+	}
+}