add tests

cluster/node.go

@@ -19,10 +19,11 @@ const (
 
 func NewNode(id string, addr string) *Node {
 	e := &Node{
-		ID:     id,
+		ID:         id,
-		Addr:   addr,
+		Addr:       addr,
-		Labels: make(map[string]string),
+		Labels:     make(map[string]string),
-		ch:     make(chan bool),
+		ch:         make(chan bool),
+		containers: make(map[string]*Container),
 	}
 	return e
 }
@@ -296,3 +297,12 @@ func (n *Node) handler(ev *dockerclient.Event, args ...interface{}) {
 
 	n.eventHandler.Handle(event)
 }
+
+// Used only on tests
+func (n *Node) AddContainer(container *Container) {
+	n.containers[container.Id] = container
+}
+
+func (n *Node) CleanupContainers() {
+	n.containers = make(map[string]*Container)
+}

scheduler/strategy/binpacking_test.go

@@ -0,0 +1,99 @@
+package strategy
+
+import (
+	"testing"
+
+	"github.com/docker/swarm/cluster"
+	"github.com/samalba/dockerclient"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPlaceContainer(t *testing.T) {
+	var (
+		s = &BinPackingPlacementStrategy{}
+
+		nodes = []*cluster.Node{
+			cluster.NewNode("node-1", ""),
+			cluster.NewNode("node-2", ""),
+			cluster.NewNode("node-3", ""),
+		}
+
+		config1 = &dockerclient.ContainerConfig{Memory: 1024 * 1024 * 1024, CpuShares: 1}
+		config2 = &dockerclient.ContainerConfig{Memory: 2 * 1024 * 1024 * 1024, CpuShares: 1}
+
+		container1 = &cluster.Container{Container: dockerclient.Container{Id: "c1"},
+			Info: dockerclient.ContainerInfo{Config: config1}}
+		container2 = &cluster.Container{Container: dockerclient.Container{Id: "c2"},
+			Info: dockerclient.ContainerInfo{Config: config1}}
+		container3 = &cluster.Container{Container: dockerclient.Container{Id: "c3"},
+			Info: dockerclient.ContainerInfo{Config: config2}}
+		container4 = &cluster.Container{Container: dockerclient.Container{Id: "c4"},
+			Info: dockerclient.ContainerInfo{Config: config1}}
+		container5 = &cluster.Container{Container: dockerclient.Container{Id: "c5"},
+			Info: dockerclient.ContainerInfo{Config: config1}}
+		container6 = &cluster.Container{Container: dockerclient.Container{Id: "c6"},
+			Info: dockerclient.ContainerInfo{Config: config1}}
+	)
+
+	for _, node := range nodes {
+		node.Memory = 2 * 1024 * 1024 * 1024
+		node.Cpus = 4
+	}
+
+	// add one container 1G
+	node1, err := s.PlaceContainer(config1, nodes)
+	assert.NoError(t, err)
+	node1.AddContainer(container1)
+
+	// add another container 1G
+	node2, err := s.PlaceContainer(config1, nodes)
+	assert.NoError(t, err)
+	node2.AddContainer(container2)
+
+	// check that both containers ended on the same node
+	assert.Equal(t, node1.ID, node2.ID, "")
+	assert.Equal(t, len(node1.Containers()), len(node2.Containers()), "")
+
+	// add another container 2G
+	node3, err := s.PlaceContainer(config2, nodes)
+	assert.NoError(t, err)
+	node3.AddContainer(container3)
+
+	// check that it ends up on another node
+	assert.NotEqual(t, node1.ID, node3.ID, "")
+
+	// add another container 1G
+	node4, err := s.PlaceContainer(config1, nodes)
+	assert.NoError(t, err)
+	node4.AddContainer(container4)
+
+	// check that it ends up on another node
+	assert.NotEqual(t, node1.ID, node4.ID, "")
+	assert.NotEqual(t, node3.ID, node4.ID, "")
+
+	// add another container 1G
+	node5, err := s.PlaceContainer(config1, nodes)
+	assert.NoError(t, err)
+	node5.AddContainer(container5)
+
+	// check that it ends up on the same node
+	assert.Equal(t, node4.ID, node5.ID, "")
+
+	// try to add another container
+	_, err = s.PlaceContainer(config1, nodes)
+
+	// check that it refuses because the cluster is full
+	assert.Error(t, err)
+
+	// remove container in the middle
+	node3.CleanupContainers()
+
+	// add another container
+	node6, err := s.PlaceContainer(config1, nodes)
+	assert.NoError(t, err)
+	node6.AddContainer(container6)
+
+	// check it ends up on `node3`
+	assert.Equal(t, node3.ID, node6.ID, "")
+	assert.Equal(t, len(node3.Containers()), len(node6.Containers()), "")
+}