Allow user-configurable DOCKER_HOST

actions/check.go

@@ -8,9 +8,7 @@ import (
 
 func watchtowerContainersFilter(c container.Container) bool { return c.IsWatchtower() }
 
-func CheckPrereqs() error {
+func CheckPrereqs(client container.Client) error {
-	client := container.NewClient()
-
 	containers, err := client.ListContainers(watchtowerContainersFilter)
 	if err != nil {
 		return err

actions/check_test.go

@@ -0,0 +1,81 @@
+package actions
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/CenturyLinkLabs/watchtower/container"
+	"github.com/CenturyLinkLabs/watchtower/container/mockclient"
+	"github.com/samalba/dockerclient"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+)
+
+func TestCheckPrereqs_Success(t *testing.T) {
+	cc := &dockerclient.ContainerConfig{
+		Labels: map[string]string{"com.centurylinklabs.watchtower": "true"},
+	}
+	c1 := *container.NewContainer(
+		&dockerclient.ContainerInfo{
+			Name:    "c1",
+			Config:  cc,
+			Created: "2015-07-01T12:00:01.000000000Z",
+		},
+		nil,
+	)
+	c2 := *container.NewContainer(
+		&dockerclient.ContainerInfo{
+			Name:    "c2",
+			Config:  cc,
+			Created: "2015-07-01T12:00:00.000000000Z",
+		},
+		nil,
+	)
+	cs := []container.Container{c1, c2}
+
+	client := &mockclient.MockClient{}
+	client.On("ListContainers", mock.AnythingOfType("container.ContainerFilter")).Return(cs, nil)
+	client.On("Stop", c2, time.Duration(60)).Return(nil)
+
+	err := CheckPrereqs(client)
+
+	assert.NoError(t, err)
+	client.AssertExpectations(t)
+}
+
+func TestCheckPrereqs_OnlyOneContainer(t *testing.T) {
+	cc := &dockerclient.ContainerConfig{
+		Labels: map[string]string{"com.centurylinklabs.watchtower": "true"},
+	}
+	c1 := *container.NewContainer(
+		&dockerclient.ContainerInfo{
+			Name:    "c1",
+			Config:  cc,
+			Created: "2015-07-01T12:00:01.000000000Z",
+		},
+		nil,
+	)
+	cs := []container.Container{c1}
+
+	client := &mockclient.MockClient{}
+	client.On("ListContainers", mock.AnythingOfType("container.ContainerFilter")).Return(cs, nil)
+
+	err := CheckPrereqs(client)
+
+	assert.NoError(t, err)
+	client.AssertExpectations(t)
+}
+
+func TestCheckPrereqs_ListError(t *testing.T) {
+	cs := []container.Container{}
+
+	client := &mockclient.MockClient{}
+	client.On("ListContainers", mock.AnythingOfType("container.ContainerFilter")).Return(cs, errors.New("oops"))
+
+	err := CheckPrereqs(client)
+
+	assert.Error(t, err)
+	assert.EqualError(t, err, "oops")
+	client.AssertExpectations(t)
+}

actions/update.go

@@ -12,8 +12,7 @@ var (
 
 func allContainersFilter(container.Container) bool { return true }
 
-func Update() error {
+func Update(client container.Client) error {
-	client := container.NewClient()
 	containers, err := client.ListContainers(allContainersFilter)
 	if err != nil {
 		return err

actions/update_test.go

@@ -5,17 +5,18 @@ import (
 	"testing"
 
 	"github.com/CenturyLinkLabs/watchtower/container"
+	"github.com/samalba/dockerclient"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCheckDependencies(t *testing.T) {
 	cs := []container.Container{
-		container.NewTestContainer("1", []string{}),
+		newTestContainer("1", []string{}),
-		container.NewTestContainer("2", []string{"1:"}),
+		newTestContainer("2", []string{"1:"}),
-		container.NewTestContainer("3", []string{"2:"}),
+		newTestContainer("3", []string{"2:"}),
-		container.NewTestContainer("4", []string{"3:"}),
+		newTestContainer("4", []string{"3:"}),
-		container.NewTestContainer("5", []string{"4:"}),
+		newTestContainer("5", []string{"4:"}),
-		container.NewTestContainer("6", []string{"5:"}),
+		newTestContainer("6", []string{"5:"}),
 	}
 	cs[3].Stale = true
 
@@ -36,3 +37,15 @@ func TestRandName(t *testing.T) {
 
 	assert.True(t, validPattern.MatchString(name))
 }
+
+func newTestContainer(name string, links []string) container.Container {
+	return *container.NewContainer(
+		&dockerclient.ContainerInfo{
+			Name: name,
+			HostConfig: &dockerclient.HostConfig{
+				Links: links,
+			},
+		},
+		nil,
+	)
+}

container/client.go

@@ -32,8 +32,8 @@ type Client interface {
 	Rename(Container, string) error
 }
 
-func NewClient() Client {
+func NewClient(dockerHost string) Client {
-	docker, err := dockerclient.NewDockerClient("unix:///var/run/docker.sock", nil)
+	docker, err := dockerclient.NewDockerClient(dockerHost, nil)
 
 	if err != nil {
 		log.Fatalf("Error instantiating Docker client: %s\n", err)

container/container.go

@@ -7,6 +7,13 @@ import (
 	"github.com/samalba/dockerclient"
 )
 
+func NewContainer(containerInfo *dockerclient.ContainerInfo, imageInfo *dockerclient.ImageInfo) *Container {
+	return &Container{
+		containerInfo: containerInfo,
+		imageInfo:     imageInfo,
+	}
+}
+
 type Container struct {
 	Stale bool
 
@@ -95,14 +102,3 @@ func (c Container) hostConfig() *dockerclient.HostConfig {
 
 	return hostConfig
 }
-
-func NewTestContainer(name string, links []string) Container {
-	return Container{
-		containerInfo: &dockerclient.ContainerInfo{
-			Name: name,
-			HostConfig: &dockerclient.HostConfig{
-				Links: links,
-			},
-		},
-	}
-}

container/mockclient/mock.go

@@ -0,0 +1,37 @@
+package mockclient
+
+import (
+	"time"
+
+	"github.com/CenturyLinkLabs/watchtower/container"
+	"github.com/stretchr/testify/mock"
+)
+
+type MockClient struct {
+	mock.Mock
+}
+
+func (m *MockClient) ListContainers(cf container.ContainerFilter) ([]container.Container, error) {
+	args := m.Called(cf)
+	return args.Get(0).([]container.Container), args.Error(1)
+}
+
+func (m *MockClient) RefreshImage(c *container.Container) error {
+	args := m.Called(c)
+	return args.Error(0)
+}
+
+func (m *MockClient) Stop(c container.Container, timeout time.Duration) error {
+	args := m.Called(c, timeout)
+	return args.Error(0)
+}
+
+func (m *MockClient) Start(c container.Container) error {
+	args := m.Called(c)
+	return args.Error(0)
+}
+
+func (m *MockClient) Rename(c container.Container, name string) error {
+	args := m.Called(c, name)
+	return args.Error(0)
+}

container/mockclient/mock_test.go

@@ -0,0 +1,17 @@
+package mockclient
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/CenturyLinkLabs/watchtower/container"
+)
+
+func TestMockInterface(t *testing.T) {
+	iface := reflect.TypeOf((*container.Client)(nil)).Elem()
+	mock := &MockClient{}
+
+	if !reflect.TypeOf(mock).Implements(iface) {
+		t.Fatalf("Mock does not implement the Client interface")
+	}
+}

container/sort_test.go

@@ -32,12 +32,12 @@ func TestByCreated(t *testing.T) {
 }
 
 func TestSortByDependencies_Success(t *testing.T) {
-	c1 := NewTestContainer("1", []string{})
+	c1 := newTestContainer("1", []string{})
-	c2 := NewTestContainer("2", []string{"1:"})
+	c2 := newTestContainer("2", []string{"1:"})
-	c3 := NewTestContainer("3", []string{"2:"})
+	c3 := newTestContainer("3", []string{"2:"})
-	c4 := NewTestContainer("4", []string{"3:"})
+	c4 := newTestContainer("4", []string{"3:"})
-	c5 := NewTestContainer("5", []string{"4:"})
+	c5 := newTestContainer("5", []string{"4:"})
-	c6 := NewTestContainer("6", []string{"5:", "3:"})
+	c6 := newTestContainer("6", []string{"5:", "3:"})
 	containers := []Container{c6, c2, c4, c1, c3, c5}
 
 	result, err := SortByDependencies(containers)
@@ -47,9 +47,9 @@ func TestSortByDependencies_Success(t *testing.T) {
 }
 
 func TestSortByDependencies_Error(t *testing.T) {
-	c1 := NewTestContainer("1", []string{"3:"})
+	c1 := newTestContainer("1", []string{"3:"})
-	c2 := NewTestContainer("2", []string{"1:"})
+	c2 := newTestContainer("2", []string{"1:"})
-	c3 := NewTestContainer("3", []string{"2:"})
+	c3 := newTestContainer("3", []string{"2:"})
 	containers := []Container{c1, c2, c3}
 
 	_, err := SortByDependencies(containers)
@@ -57,3 +57,15 @@ func TestSortByDependencies_Error(t *testing.T) {
 	assert.Error(t, err)
 	assert.EqualError(t, err, "Circular reference to 1")
 }
+
+func newTestContainer(name string, links []string) Container {
+	return *NewContainer(
+		&dockerclient.ContainerInfo{
+			Name: name,
+			HostConfig: &dockerclient.HostConfig{
+				Links: links,
+			},
+		},
+		nil,
+	)
+}

main.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/CenturyLinkLabs/watchtower/actions"
+	"github.com/CenturyLinkLabs/watchtower/container"
 	"github.com/codegangsta/cli"
 )
 
@@ -23,6 +24,12 @@ func main() {
 	app.Before = before
 	app.Action = start
 	app.Flags = []cli.Flag{
+		cli.StringFlag{
+			Name:   "host, H",
+			Value:  "unix:///var/run/docker.sock",
+			Usage:  "Docker daemon socket to connect to",
+			EnvVar: "DOCKER_HOST",
+		},
 		cli.IntFlag{
 			Name:  "interval, i",
 			Value: 300,
@@ -48,15 +55,17 @@ func handleSignals() {
 }
 
 func before(c *cli.Context) error {
-	return actions.CheckPrereqs()
+	client := newContainerClient(c)
+	return actions.CheckPrereqs(client)
 }
 
 func start(c *cli.Context) {
+	client := newContainerClient(c)
 	secs := time.Duration(c.Int("interval")) * time.Second
 
 	for {
 		wg.Add(1)
-		if err := actions.Update(); err != nil {
+		if err := actions.Update(client); err != nil {
 			fmt.Println(err)
 		}
 		wg.Done()
@@ -64,3 +73,8 @@ func start(c *cli.Context) {
 		time.Sleep(secs)
 	}
 }
+
+func newContainerClient(c *cli.Context) container.Client {
+	dockerHost := c.GlobalString("host")
+	return container.NewClient(dockerHost)
+}