add tests for check action, resolve wt cleanup bug (#284)

add unit tests for the check action to allow for some
refactoring and bug fixing without having to worry about
breaking stuff.

resolve watchtower cleanup bug by adding an initial 1 second sleep
in the check action. without the sleep, the docker client returns an
empty array, which is why we were left with two watchtowers.

actions/actions_suite_test.go

@@ -0,0 +1,173 @@
+package actions_test
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/containrrr/watchtower/actions"
+	"github.com/containrrr/watchtower/container"
+	"github.com/containrrr/watchtower/container/mocks"
+	"github.com/docker/docker/api/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,
+			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,
+					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,
+					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
+}
+
+type TestData struct {
+	TriedToRemoveImage    bool
+	NameOfContainerToKeep string
+	Containers            []container.Container
+}
+
+func (client mockClient) ListContainers(f container.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")
+}