Fix up usage and tests, split into multiple files.

Doing this in multiple commits in an attempt to preserve the file movement history.

pkg/scheduler/doc.go

@@ -0,0 +1,19 @@
+/*
+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 scheduler contains a generic Scheduler interface and several
+// implementations.
+package scheduler

pkg/scheduler/firstfit.go

@@ -0,0 +1,86 @@
+/*
+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 scheduler
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+)
+
+type FirstFitScheduler struct {
+	podLister PodLister
+	// TODO: *rand.Rand is *not* threadsafe
+	random *rand.Rand
+}
+
+func MakeFirstFitScheduler(podLister PodLister, random *rand.Rand) Scheduler {
+	return &FirstFitScheduler{
+		podLister: podLister,
+		random:    random,
+	}
+}
+
+func (s *FirstFitScheduler) containsPort(pod api.Pod, port api.Port) bool {
+	for _, container := range pod.DesiredState.Manifest.Containers {
+		for _, podPort := range container.Ports {
+			if podPort.HostPort == port.HostPort {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (s *FirstFitScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
+	machines, err := minionLister.List()
+	if err != nil {
+		return "", err
+	}
+	machineToPods := map[string][]api.Pod{}
+	pods, err := s.podLister.ListPods(labels.Everything())
+	if err != nil {
+		return "", err
+	}
+	for _, scheduledPod := range pods {
+		host := scheduledPod.CurrentState.Host
+		machineToPods[host] = append(machineToPods[host], scheduledPod)
+	}
+	var machineOptions []string
+	for _, machine := range machines {
+		podFits := true
+		for _, scheduledPod := range machineToPods[machine] {
+			for _, container := range pod.DesiredState.Manifest.Containers {
+				for _, port := range container.Ports {
+					if s.containsPort(scheduledPod, port) {
+						podFits = false
+					}
+				}
+			}
+		}
+		if podFits {
+			machineOptions = append(machineOptions, machine)
+		}
+	}
+	if len(machineOptions) == 0 {
+		return "", fmt.Errorf("failed to find fit for %#v", pod)
+	} else {
+		return machineOptions[s.random.Int()%len(machineOptions)], nil
+	}
+}

pkg/scheduler/firstfit_test.go

@@ -0,0 +1,78 @@
+/*
+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 scheduler
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+func TestFirstFitSchedulerNothingScheduled(t *testing.T) {
+	fakeRegistry := FakePodLister{}
+	r := rand.New(rand.NewSource(0))
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeFirstFitScheduler(&fakeRegistry, r),
+		minionLister: FakeMinionLister{"m1", "m2", "m3"},
+	}
+	st.expectSchedule(api.Pod{}, "m3")
+}
+
+func TestFirstFitSchedulerFirstScheduled(t *testing.T) {
+	fakeRegistry := FakePodLister{
+		makePod("m1", 8080),
+	}
+	r := rand.New(rand.NewSource(0))
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeFirstFitScheduler(fakeRegistry, r),
+		minionLister: FakeMinionLister{"m1", "m2", "m3"},
+	}
+	st.expectSchedule(makePod("", 8080), "m3")
+}
+
+func TestFirstFitSchedulerFirstScheduledComplicated(t *testing.T) {
+	fakeRegistry := FakePodLister{
+		makePod("m1", 80, 8080),
+		makePod("m2", 8081, 8082, 8083),
+		makePod("m3", 80, 443, 8085),
+	}
+	r := rand.New(rand.NewSource(0))
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeFirstFitScheduler(fakeRegistry, r),
+		minionLister: FakeMinionLister{"m1", "m2", "m3"},
+	}
+	st.expectSchedule(makePod("", 8080, 8081), "m3")
+}
+
+func TestFirstFitSchedulerFirstScheduledImpossible(t *testing.T) {
+	fakeRegistry := FakePodLister{
+		makePod("m1", 8080),
+		makePod("m2", 8081),
+		makePod("m3", 8080),
+	}
+	r := rand.New(rand.NewSource(0))
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeFirstFitScheduler(fakeRegistry, r),
+		minionLister: FakeMinionLister{"m1", "m2", "m3"},
+	}
+	st.expectFailure(makePod("", 8080, 8081))
+}

pkg/scheduler/listers.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.
+*/
+
+package scheduler
+
+import (
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+)
+
+// Anything that can list minions for a scheduler.
+type MinionLister interface {
+	List() (machines []string, err error)
+}
+
+// Make a MinionLister from a []string
+type FakeMinionLister []string
+
+// Returns minions as a []string
+func (f FakeMinionLister) List() ([]string, error) {
+	return []string(f), nil
+}
+
+// Anything that can list pods for a scheduler
+type PodLister interface {
+	ListPods(labels.Selector) ([]api.Pod, error)
+}
+
+// Make a MinionLister from an []api.Pods
+type FakePodLister []api.Pod
+
+func (f FakePodLister) ListPods(s labels.Selector) (selected []api.Pod, err error) {
+	for _, pod := range f {
+		if s.Matches(labels.Set(pod.Labels)) {
+			selected = append(selected, pod)
+		}
+	}
+	return selected, nil
+}

pkg/scheduler/random.go

@@ -0,0 +1,43 @@
+/*
+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 scheduler
+
+import (
+	"math/rand"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+// RandomScheduler choses machines uniformly at random.
+type RandomScheduler struct {
+	// TODO: rand.Rand is *NOT* thread safe.
+	random *rand.Rand
+}
+
+func MakeRandomScheduler(random *rand.Rand) Scheduler {
+	return &RandomScheduler{
+		random: random,
+	}
+}
+
+func (s *RandomScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
+	machines, err := minionLister.List()
+	if err != nil {
+		return "", err
+	}
+	return machines[s.random.Int()%len(machines)], nil
+}

pkg/scheduler/random_test.go

@@ -0,0 +1,34 @@
+/*
+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 scheduler
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+func TestRandomScheduler(t *testing.T) {
+	random := rand.New(rand.NewSource(0))
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeRandomScheduler(random),
+		minionLister: FakeMinionLister{"m1", "m2", "m3", "m4"},
+	}
+	st.expectSuccess(api.Pod{})
+}

pkg/scheduler/roundrobin.go

@@ -0,0 +1,42 @@
+/*
+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 scheduler
+
+import (
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+// RoundRobinScheduler chooses machines in order.
+type RoundRobinScheduler struct {
+	currentIndex int
+}
+
+func MakeRoundRobinScheduler() Scheduler {
+	return &RoundRobinScheduler{
+		currentIndex: -1,
+	}
+}
+
+func (s *RoundRobinScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
+	machines, err := minionLister.List()
+	if err != nil {
+		return "", err
+	}
+	s.currentIndex = (s.currentIndex + 1) % len(machines)
+	result := machines[s.currentIndex]
+	return result, nil
+}

pkg/scheduler/roundrobin_test.go

@@ -0,0 +1,35 @@
+/*
+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 scheduler
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+)
+
+func TestRoundRobinScheduler(t *testing.T) {
+	st := schedulerTester{
+		t:            t,
+		scheduler:    MakeRoundRobinScheduler(),
+		minionLister: FakeMinionLister{"m1", "m2", "m3", "m4"},
+	}
+	st.expectSchedule(api.Pod{}, "m1")
+	st.expectSchedule(api.Pod{}, "m2")
+	st.expectSchedule(api.Pod{}, "m3")
+	st.expectSchedule(api.Pod{}, "m4")
+}

pkg/scheduler/scheduler.go

@@ -14,129 +14,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package registry
+package scheduler
 
 import (
-	"fmt"
-	"math/rand"
-
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
-	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 )
 
-// Anything that can list minions for a scheduler.
-type MinionLister interface {
-	List() (machines []string, err error)
-}
-
-// Make a MinionLister from a []string
-type StringMinionLister []string
-
-func (s StringMinionLister) List() ([]string, error) {
-	return []string(s), nil
-}
-
-// Scheduler is an interface implemented by things that know how to schedule pods onto machines.
+// Scheduler is an interface implemented by things that know how to schedule pods
+// onto machines.
 type Scheduler interface {
-	Schedule(api.Pod, MinionLister) (string, error)
-}
-
-// RandomScheduler choses machines uniformly at random.
-type RandomScheduler struct {
-	random rand.Rand
-}
-
-func MakeRandomScheduler(random rand.Rand) Scheduler {
-	return &RandomScheduler{
-		random: random,
-	}
-}
-
-func (s *RandomScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
-	machines, err := minionLister.List()
-	if err != nil {
-		return "", err
-	}
-	return machines[s.random.Int()%len(machines)], nil
-}
-
-// RoundRobinScheduler chooses machines in order.
-type RoundRobinScheduler struct {
-	currentIndex int
-}
-
-func MakeRoundRobinScheduler() Scheduler {
-	return &RoundRobinScheduler{
-		currentIndex: -1,
-	}
-}
-
-func (s *RoundRobinScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
-	machines, err := minionLister.List()
-	if err != nil {
-		return "", err
-	}
-	s.currentIndex = (s.currentIndex + 1) % len(machines)
-	result := machines[s.currentIndex]
-	return result, nil
-}
-
-type FirstFitScheduler struct {
-	registry PodRegistry
-	random   *rand.Rand
-}
-
-func MakeFirstFitScheduler(registry PodRegistry, random *rand.Rand) Scheduler {
-	return &FirstFitScheduler{
-		registry: registry,
-		random:   random,
-	}
-}
-
-func (s *FirstFitScheduler) containsPort(pod api.Pod, port api.Port) bool {
-	for _, container := range pod.DesiredState.Manifest.Containers {
-		for _, podPort := range container.Ports {
-			if podPort.HostPort == port.HostPort {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-func (s *FirstFitScheduler) Schedule(pod api.Pod, minionLister MinionLister) (string, error) {
-	machines, err := minionLister.List()
-	if err != nil {
-		return "", err
-	}
-	machineToPods := map[string][]api.Pod{}
-	pods, err := s.registry.ListPods(labels.Everything())
-	if err != nil {
-		return "", err
-	}
-	for _, scheduledPod := range pods {
-		host := scheduledPod.CurrentState.Host
-		machineToPods[host] = append(machineToPods[host], scheduledPod)
-	}
-	var machineOptions []string
-	for _, machine := range machines {
-		podFits := true
-		for _, scheduledPod := range machineToPods[machine] {
-			for _, container := range pod.DesiredState.Manifest.Containers {
-				for _, port := range container.Ports {
-					if s.containsPort(scheduledPod, port) {
-						podFits = false
-					}
-				}
-			}
-		}
-		if podFits {
-			machineOptions = append(machineOptions, machine)
-		}
-	}
-	if len(machineOptions) == 0 {
-		return "", fmt.Errorf("failed to find fit for %#v", pod)
-	} else {
-		return machineOptions[s.random.Int()%len(machineOptions)], nil
-	}
+	Schedule(api.Pod, MinionLister) (selectedMachine string, err error)
 }

pkg/scheduler/scheduler_test.go

@@ -14,43 +14,49 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package registry
+package scheduler
 
 import (
-	"math/rand"
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 )
 
-func expectSchedule(scheduler Scheduler, pod api.Pod, expected string, t *testing.T) {
-	actual, err := scheduler.Schedule(pod)
-	expectNoError(t, err)
+// Some functions used by multiple scheduler tests.
+
+type schedulerTester struct {
+	t            *testing.T
+	scheduler    Scheduler
+	minionLister MinionLister
+}
+
+// Call if you know exactly where pod should get scheduled.
+func (st *schedulerTester) expectSchedule(pod api.Pod, expected string) {
+	actual, err := st.scheduler.Schedule(pod, st.minionLister)
+	if err != nil {
+		st.t.Errorf("Unexpected error %v\nTried to scheduler: %#v", err, pod)
+		return
+	}
 	if actual != expected {
-		t.Errorf("Unexpected scheduling value: %v, expected %v", actual, expected)
+		st.t.Errorf("Unexpected scheduling value: %v, expected %v", actual, expected)
 	}
 }
 
-func TestRoundRobinScheduler(t *testing.T) {
-	scheduler := MakeRoundRobinScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3", "m4"}))
-	expectSchedule(scheduler, api.Pod{}, "m1", t)
-	expectSchedule(scheduler, api.Pod{}, "m2", t)
-	expectSchedule(scheduler, api.Pod{}, "m3", t)
-	expectSchedule(scheduler, api.Pod{}, "m4", t)
+// Call if you can't predict where pod will be scheduled.
+func (st *schedulerTester) expectSuccess(pod api.Pod) {
+	_, err := st.scheduler.Schedule(pod, st.minionLister)
+	if err != nil {
+		st.t.Errorf("Unexpected error %v\nTried to scheduler: %#v", err, pod)
+		return
+	}
 }
 
-func TestRandomScheduler(t *testing.T) {
-	random := rand.New(rand.NewSource(0))
-	scheduler := MakeRandomScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3", "m4"}), *random)
-	_, err := scheduler.Schedule(api.Pod{})
-	expectNoError(t, err)
-}
-
-func TestFirstFitSchedulerNothingScheduled(t *testing.T) {
-	mockRegistry := MockPodRegistry{}
-	r := rand.New(rand.NewSource(0))
-	scheduler := MakeFirstFitScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3"}), &mockRegistry, r)
-	expectSchedule(scheduler, api.Pod{}, "m3", t)
+// Call if pod should *not* schedule.
+func (st *schedulerTester) expectFailure(pod api.Pod) {
+	_, err := st.scheduler.Schedule(pod, st.minionLister)
+	if err == nil {
+		st.t.Error("Unexpected non-error")
+	}
 }
 
 func makePod(host string, hostPorts ...int) api.Pod {
@@ -73,43 +79,3 @@ func makePod(host string, hostPorts ...int) api.Pod {
 		},
 	}
 }
-
-func TestFirstFitSchedulerFirstScheduled(t *testing.T) {
-	mockRegistry := MockPodRegistry{
-		pods: []api.Pod{
-			makePod("m1", 8080),
-		},
-	}
-	r := rand.New(rand.NewSource(0))
-	scheduler := MakeFirstFitScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3"}), &mockRegistry, r)
-	expectSchedule(scheduler, makePod("", 8080), "m3", t)
-}
-
-func TestFirstFitSchedulerFirstScheduledComplicated(t *testing.T) {
-	mockRegistry := MockPodRegistry{
-		pods: []api.Pod{
-			makePod("m1", 80, 8080),
-			makePod("m2", 8081, 8082, 8083),
-			makePod("m3", 80, 443, 8085),
-		},
-	}
-	r := rand.New(rand.NewSource(0))
-	scheduler := MakeFirstFitScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3"}), &mockRegistry, r)
-	expectSchedule(scheduler, makePod("", 8080, 8081), "m3", t)
-}
-
-func TestFirstFitSchedulerFirstScheduledImpossible(t *testing.T) {
-	mockRegistry := MockPodRegistry{
-		pods: []api.Pod{
-			makePod("m1", 8080),
-			makePod("m2", 8081),
-			makePod("m3", 8080),
-		},
-	}
-	r := rand.New(rand.NewSource(0))
-	scheduler := MakeFirstFitScheduler(MakeMinionRegistry([]string{"m1", "m2", "m3"}), &mockRegistry, r)
-	_, err := scheduler.Schedule(makePod("", 8080, 8081))
-	if err == nil {
-		t.Error("Unexpected non-error.")
-	}
-}