refactor: move actions into internal

internal/actions/actions_suite_test.go

@@ -0,0 +1,178 @@
+package actions_test
+
+import (
+	"errors"
+	"github.com/containrrr/watchtower/internal/actions"
+	"testing"
+	"time"
+
+	"github.com/containrrr/watchtower/pkg/container"
+	"github.com/containrrr/watchtower/pkg/container/mocks"
+	"github.com/docker/docker/api/types"
+
+	t "github.com/containrrr/watchtower/pkg/types"
+	cli "github.com/docker/docker/client"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestActions(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Actions Suite")
+}
+
+var _ = Describe("the actions package", func() {
+	var dockerClient cli.CommonAPIClient
+	var client mockClient
+	BeforeSuite(func() {
+		server := mocks.NewMockAPIServer()
+		dockerClient, _ = cli.NewClientWithOpts(
+			cli.WithHost(server.URL),
+			cli.WithHTTPClient(server.Client()))
+	})
+	BeforeEach(func() {
+		client = mockClient{
+			api:           dockerClient,
+			pullImages:    false,
+			removeVolumes: false,
+			TestData:      &TestData{},
+		}
+	})
+
+	Describe("the check prerequisites method", func() {
+		When("given an empty array", func() {
+			It("should not do anything", func() {
+				client.TestData.Containers = []container.Container{}
+				err := actions.CheckForMultipleWatchtowerInstances(client, false)
+				Expect(err).NotTo(HaveOccurred())
+			})
+		})
+		When("given an array of one", func() {
+			It("should not do anything", func() {
+				client.TestData.Containers = []container.Container{
+					createMockContainer(
+						"test-container",
+						"test-container",
+						"watchtower",
+						time.Now()),
+				}
+				err := actions.CheckForMultipleWatchtowerInstances(client, false)
+				Expect(err).NotTo(HaveOccurred())
+			})
+		})
+		When("given multiple containers", func() {
+			BeforeEach(func() {
+				client = mockClient{
+					api:           dockerClient,
+					pullImages:    false,
+					removeVolumes: false,
+					TestData: &TestData{
+						NameOfContainerToKeep: "test-container-02",
+						Containers: []container.Container{
+							createMockContainer(
+								"test-container-01",
+								"test-container-01",
+								"watchtower",
+								time.Now().AddDate(0, 0, -1)),
+							createMockContainer(
+								"test-container-02",
+								"test-container-02",
+								"watchtower",
+								time.Now()),
+						},
+					},
+				}
+			})
+			It("should stop all but the latest one", func() {
+				err := actions.CheckForMultipleWatchtowerInstances(client, false)
+				Expect(err).NotTo(HaveOccurred())
+			})
+		})
+		When("deciding whether to cleanup images", func() {
+			BeforeEach(func() {
+				client = mockClient{
+					api:           dockerClient,
+					pullImages:    false,
+					removeVolumes: false,
+					TestData: &TestData{
+						Containers: []container.Container{
+							createMockContainer(
+								"test-container-01",
+								"test-container-01",
+								"watchtower",
+								time.Now().AddDate(0, 0, -1)),
+							createMockContainer(
+								"test-container-02",
+								"test-container-02",
+								"watchtower",
+								time.Now()),
+						},
+					},
+				}
+			})
+			It("should try to delete the image if the cleanup flag is true", func() {
+				err := actions.CheckForMultipleWatchtowerInstances(client, true)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(client.TestData.TriedToRemoveImage).To(BeTrue())
+			})
+			It("should not try to delete the image if the cleanup flag is false", func() {
+				err := actions.CheckForMultipleWatchtowerInstances(client, false)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(client.TestData.TriedToRemoveImage).To(BeFalse())
+			})
+		})
+	})
+})
+
+func createMockContainer(id string, name string, image string, created time.Time) container.Container {
+	content := types.ContainerJSON{
+		ContainerJSONBase: &types.ContainerJSONBase{
+			ID:      id,
+			Image:   image,
+			Name:    name,
+			Created: created.String(),
+		},
+	}
+	return *container.NewContainer(&content, nil)
+}
+
+type mockClient struct {
+	TestData      *TestData
+	api           cli.CommonAPIClient
+	pullImages    bool
+	removeVolumes bool
+}
+
+type TestData struct {
+	TriedToRemoveImage    bool
+	NameOfContainerToKeep string
+	Containers            []container.Container
+}
+
+func (client mockClient) ListContainers(f t.Filter) ([]container.Container, error) {
+	return client.TestData.Containers, nil
+}
+
+func (client mockClient) StopContainer(c container.Container, d time.Duration) error {
+	if c.Name() == client.TestData.NameOfContainerToKeep {
+		return errors.New("tried to stop the instance we want to keep")
+	}
+	return nil
+}
+func (client mockClient) StartContainer(c container.Container) error {
+	panic("Not implemented")
+}
+
+func (client mockClient) RenameContainer(c container.Container, s string) error {
+	panic("Not implemented")
+}
+
+func (client mockClient) RemoveImage(c container.Container) error {
+	client.TestData.TriedToRemoveImage = true
+	return nil
+}
+
+func (client mockClient) IsContainerStale(c container.Container) (bool, error) {
+	panic("Not implemented")
+}

internal/actions/check.go

@@ -0,0 +1,84 @@
+package actions
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/opencontainers/runc/Godeps/_workspace/src/github.com/Sirupsen/logrus"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/containrrr/watchtower/pkg/container"
+)
+
+// CheckForMultipleWatchtowerInstances will ensure that there are not multiple instances of the
+// watchtower running simultaneously. If multiple watchtower containers are detected, this function
+// will stop and remove all but the most recently started container.
+func CheckForMultipleWatchtowerInstances(client container.Client, cleanup bool) error {
+	awaitDockerClient()
+	containers, err := client.ListContainers(container.WatchtowerContainersFilter)
+
+	if err != nil {
+		log.Fatal(err)
+		return err
+	}
+
+	if len(containers) <= 1 {
+		log.Debug("There are no additional watchtower containers")
+		return nil
+	}
+
+	log.Info("Found multiple running watchtower instances. Cleaning up.")
+	return cleanupExcessWatchtowers(containers, client, cleanup)
+}
+
+func cleanupExcessWatchtowers(containers []container.Container, client container.Client, cleanup bool) error {
+	var cleanupErrors int
+	var stopErrors int
+
+	sort.Sort(container.ByCreated(containers))
+	allContainersExceptLast := containers[0 : len(containers)-1]
+
+	for _, c := range allContainersExceptLast {
+		if err := client.StopContainer(c, 60); err != nil {
+			// logging the original here as we're just returning a count
+			logrus.Error(err)
+			stopErrors++
+			continue
+		}
+
+		if cleanup == true {
+			if err := client.RemoveImage(c); err != nil {
+				// logging the original here as we're just returning a count
+				logrus.Error(err)
+				cleanupErrors++
+			}
+		}
+	}
+
+	return createErrorIfAnyHaveOccurred(stopErrors, cleanupErrors)
+}
+
+func createErrorIfAnyHaveOccurred(c int, i int) error {
+	if c == 0 && i == 0 {
+		return nil
+	}
+
+	var output strings.Builder
+
+	if c > 0 {
+		output.WriteString(fmt.Sprintf("%d errors while stopping containers", c))
+	}
+	if i > 0 {
+		output.WriteString(fmt.Sprintf("%d errors while cleaning up images", c))
+	}
+	return errors.New(output.String())
+}
+
+func awaitDockerClient() {
+	log.Debug("Sleeping for a seconds to ensure the docker api client has been properly initialized.")
+	time.Sleep(1 * time.Second)
+}

internal/actions/update.go

@@ -0,0 +1,130 @@
+package actions
+
+import (
+	"math/rand"
+	"time"
+
+	"github.com/containrrr/watchtower/pkg/container"
+	t "github.com/containrrr/watchtower/pkg/types"
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+)
+
+// UpdateParams contains all different options available to alter the behavior of the Update func
+type UpdateParams struct {
+	Filter      t.Filter
+	Cleanup     bool
+	NoRestart   bool
+	Timeout     time.Duration
+	MonitorOnly bool
+}
+
+// Update looks at the running Docker containers to see if any of the images
+// used to start those containers have been updated. If a change is detected in
+// any of the images, the associated containers are stopped and restarted with
+// the new image.
+func Update(client container.Client, params UpdateParams) error {
+	log.Debug("Checking containers for updated images")
+
+	containers, err := client.ListContainers(params.Filter)
+	if err != nil {
+		return err
+	}
+
+	for i, container := range containers {
+		stale, err := client.IsContainerStale(container)
+		if err != nil {
+			log.Infof("Unable to update container %s. Proceeding to next.", containers[i].Name())
+			log.Debug(err)
+			stale = false
+		}
+		containers[i].Stale = stale
+	}
+
+	containers, err = container.SortByDependencies(containers)
+	if err != nil {
+		return err
+	}
+
+	checkDependencies(containers)
+
+	if params.MonitorOnly {
+		return nil
+	}
+
+	// Stop stale containers in reverse order
+	for i := len(containers) - 1; i >= 0; i-- {
+		container := containers[i]
+
+		if container.IsWatchtower() {
+			log.Debugf("This is the watchtower container %s", containers[i].Name())
+			continue
+		}
+
+		if container.Stale {
+			if err := client.StopContainer(container, params.Timeout); err != nil {
+				log.Error(err)
+			}
+		}
+	}
+
+	// Restart stale containers in sorted order
+	for _, container := range containers {
+		if container.Stale {
+			// Since we can't shutdown a watchtower container immediately, we need to
+			// start the new one while the old one is still running. This prevents us
+			// from re-using the same container name so we first rename the current
+			// instance so that the new one can adopt the old name.
+			if container.IsWatchtower() {
+				if err := client.RenameContainer(container, randName()); err != nil {
+					log.Error(err)
+					continue
+				}
+			}
+
+			if !params.NoRestart {
+				if err := client.StartContainer(container); err != nil {
+					log.Error(err)
+				}
+			}
+
+			if params.Cleanup {
+				client.RemoveImage(container)
+			}
+		}
+	}
+
+	return nil
+}
+
+func checkDependencies(containers []container.Container) {
+
+	for i, parent := range containers {
+		if parent.Stale {
+			continue
+		}
+
+	LinkLoop:
+		for _, linkName := range parent.Links() {
+			for _, child := range containers {
+				if child.Name() == linkName && child.Stale {
+					containers[i].Stale = true
+					break LinkLoop
+				}
+			}
+		}
+	}
+}
+
+// Generates a random, 32-character, Docker-compatible container name.
+func randName() string {
+	b := make([]rune, 32)
+	for i := range b {
+		b[i] = letters[rand.Intn(len(letters))]
+	}
+
+	return string(b)
+}