test: refactor client tests

should not be explicitly telling what they are testing and the requirements
fixed the test data so that it doesn't contain discrepancies
fully reset the mock client (no shared state) and only support the calls that is expected

pkg/container/client_test.go

@@ -3,28 +3,33 @@ package container
 import (
 	"github.com/containrrr/watchtower/pkg/container/mocks"
 	"github.com/containrrr/watchtower/pkg/filters"
+	t "github.com/containrrr/watchtower/pkg/types"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/backend"
 	cli "github.com/docker/docker/client"
-	. "github.com/onsi/ginkgo"
-	. "github.com/onsi/gomega"
 	"github.com/onsi/gomega/gbytes"
+	"github.com/onsi/gomega/ghttp"
 	"github.com/sirupsen/logrus"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	. "github.com/onsi/gomega/types"
+
+	"net/http"
 )
 
 var _ = Describe("the client", func() {
 	var docker *cli.Client
-	var client Client
+	var mockServer *ghttp.Server
 	BeforeSuite(func() {
-		server := mocks.NewMockAPIServer()
+		mockServer = ghttp.NewServer()
 		docker, _ = cli.NewClientWithOpts(
-			cli.WithHost(server.URL),
-			cli.WithHTTPClient(server.Client()))
-		client = dockerClient{
-			api:        docker,
-			pullImages: false,
-		}
+			cli.WithHost(mockServer.URL()),
+			cli.WithHTTPClient(mockServer.HTTPTestServer.Client()))
 	})
-	It("should return a client for the api", func() {
-		Expect(client).NotTo(BeNil())
+	AfterEach(func() {
+		mockServer.Reset()
 	})
 	Describe("WarnOnHeadPullFailed", func() {
 		containerUnknown := *mockContainerWithImageName("unknown.repo/prefix/imagename:latest")
@@ -54,90 +59,152 @@ var _ = Describe("the client", func() {
 			})
 		})
 	})
-
-	When("listing containers without any filter", func() {
+	When("listing containers", func() {
+		When("no filter is provided", func() {
 			It("should return all available containers", func() {
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("watchtower", "running")...)
+				client := dockerClient{
+					api:        docker,
+					pullImages: false,
+				}
 				containers, err := client.ListContainers(filters.NoFilter)
 				Expect(err).NotTo(HaveOccurred())
-			Expect(len(containers) == 2).To(BeTrue())
+				Expect(containers).To(HaveLen(2))
 			})
 		})
-	When("listing containers with a filter matching nothing", func() {
+		When("a filter matching nothing", func() {
 			It("should return an empty array", func() {
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("watchtower", "running")...)
 				filter := filters.FilterByNames([]string{"lollercoaster"}, filters.NoFilter)
+				client := dockerClient{
+					api:        docker,
+					pullImages: false,
+				}
 				containers, err := client.ListContainers(filter)
 				Expect(err).NotTo(HaveOccurred())
-			Expect(len(containers) == 0).To(BeTrue())
+				Expect(containers).To(BeEmpty())
 			})
 		})
-	When("listing containers with a watchtower filter", func() {
+		When("a watchtower filter is provided", func() {
 			It("should return only the watchtower container", func() {
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("watchtower", "running")...)
+				client := dockerClient{
+					api:        docker,
+					pullImages: false,
+				}
 				containers, err := client.ListContainers(filters.WatchtowerContainersFilter)
 				Expect(err).NotTo(HaveOccurred())
-			Expect(len(containers) == 1).To(BeTrue())
-			Expect(containers[0].ImageName()).To(Equal("containrrr/watchtower:latest"))
+				Expect(containers).To(ConsistOf(withContainerImageName(Equal("containrrr/watchtower:latest"))))
 			})
 		})
-	When(`listing containers with the "include stopped" option`, func() {
+		When(`include stopped is enabled`, func() {
 			It("should return both stopped and running containers", func() {
-			client = dockerClient{
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running", "exited", "created"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("stopped", "watchtower", "running")...)
+				client := dockerClient{
 					api:            docker,
 					pullImages:     false,
 					includeStopped: true,
 				}
 				containers, err := client.ListContainers(filters.NoFilter)
 				Expect(err).NotTo(HaveOccurred())
-			Expect(len(containers) > 0).To(BeTrue())
+				Expect(containers).To(ContainElement(havingRunningState(false)))
 			})
 		})
-	When(`listing containers with the "include restart" option`, func() {
-		It("should return both stopped, restarting and running containers", func() {
-			client = dockerClient{
+		When(`include restarting is enabled`, func() {
+			It("should return both restarting and running containers", func() {
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running", "restarting"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("watchtower", "running", "restarting")...)
+				client := dockerClient{
 					api:               docker,
 					pullImages:        false,
 					includeRestarting: true,
 				}
 				containers, err := client.ListContainers(filters.NoFilter)
 				Expect(err).NotTo(HaveOccurred())
-			RestartingContainerFound := false
-			for _, ContainerRunning := range containers {
-				if ContainerRunning.containerInfo.State.Restarting {
-					RestartingContainerFound = true
-				}
-			}
-			Expect(RestartingContainerFound).To(BeTrue())
-			Expect(RestartingContainerFound).NotTo(BeFalse())
+				Expect(containers).To(ContainElement(havingRestartingState(true)))
 			})
 		})
-	When(`listing containers without restarting ones`, func() {
+		When(`include restarting is disabled`, func() {
 			It("should not return restarting containers", func() {
-			client = dockerClient{
+				mockServer.AppendHandlers(mocks.ListContainersHandler("running"))
+				mockServer.AppendHandlers(mocks.GetContainerHandlers("watchtower", "running")...)
+				client := dockerClient{
 					api:               docker,
 					pullImages:        false,
 					includeRestarting: false,
 				}
 				containers, err := client.ListContainers(filters.NoFilter)
 				Expect(err).NotTo(HaveOccurred())
-			RestartingContainerFound := false
-			for _, ContainerRunning := range containers {
-				if ContainerRunning.containerInfo.State.Restarting {
-					RestartingContainerFound = true
-				}
-			}
-			Expect(RestartingContainerFound).To(BeFalse())
-			Expect(RestartingContainerFound).NotTo(BeTrue())
+				Expect(containers).NotTo(ContainElement(havingRestartingState(true)))
+			})
 		})
 	})
 	Describe(`ExecuteCommand`, func() {
 		When(`logging`, func() {
 			It("should include container id field", func() {
+				client := dockerClient{
+					api:        docker,
+					pullImages: false,
+				}
+
 				// Capture logrus output in buffer
 				logbuf := gbytes.NewBuffer()
 				origOut := logrus.StandardLogger().Out
 				defer logrus.SetOutput(origOut)
 				logrus.SetOutput(logbuf)
 
-				_, err := client.ExecuteCommand("ex-cont-id", "exec-cmd", 1)
+				user := ""
+				containerID := t.ContainerID("ex-cont-id")
+				execID := "ex-exec-id"
+				cmd := "exec-cmd"
+
+				mockServer.AppendHandlers(
+					// API.ContainerExecCreate
+					ghttp.CombineHandlers(
+						ghttp.VerifyRequest("POST", HaveSuffix("containers/%v/exec", containerID)),
+						ghttp.VerifyJSONRepresenting(types.ExecConfig{
+							User:   user,
+							Detach: false,
+							Tty:    true,
+							Cmd: []string{
+								"sh",
+								"-c",
+								cmd,
+							},
+						}),
+						ghttp.RespondWithJSONEncoded(http.StatusOK, types.IDResponse{ID: execID}),
+					),
+					// API.ContainerExecStart
+					ghttp.CombineHandlers(
+						ghttp.VerifyRequest("POST", HaveSuffix("exec/%v/start", execID)),
+						ghttp.VerifyJSONRepresenting(types.ExecStartCheck{
+							Detach: false,
+							Tty:    true,
+						}),
+						ghttp.RespondWith(http.StatusOK, nil),
+					),
+					// API.ContainerExecInspect
+					ghttp.CombineHandlers(
+						ghttp.VerifyRequest("GET", HaveSuffix("exec/ex-exec-id/json")),
+						ghttp.RespondWithJSONEncoded(http.StatusOK, backend.ExecInspect{
+							ID:       execID,
+							Running:  false,
+							ExitCode: nil,
+							ProcessConfig: &backend.ExecProcessConfig{
+								Entrypoint: "sh",
+								Arguments:  []string{"-c", cmd},
+								User:       user,
+							},
+							ContainerID: string(containerID),
+						}),
+					),
+				)
+
+				_, err := client.ExecuteCommand(containerID, cmd, 1)
 				Expect(err).NotTo(HaveOccurred())
 				// Note: Since Execute requires opening up a raw TCP stream to the daemon for the output, this will fail
 				// when using the mock API server. Regardless of the outcome, the log should include the container ID
@@ -146,3 +213,25 @@ var _ = Describe("the client", func() {
 		})
 	})
 })
+
+// Gomega matcher helpers
+
+func withContainerImageName(matcher GomegaMatcher) GomegaMatcher {
+	return WithTransform(containerImageName, matcher)
+}
+
+func containerImageName(container Container) string {
+	return container.ImageName()
+}
+
+func havingRestartingState(expected bool) GomegaMatcher {
+	return WithTransform(func(container Container) bool {
+		return container.containerInfo.State.Restarting
+	}, Equal(expected))
+}
+
+func havingRunningState(expected bool) GomegaMatcher {
+	return WithTransform(func(container Container) bool {
+		return container.containerInfo.State.Running
+	}, Equal(expected))
+}

pkg/container/mocks/ApiServer.go

@@ -3,91 +3,123 @@ package mocks
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/onsi/ginkgo"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/filters"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/ghttp"
 	"io/ioutil"
 	"net/http"
-	"net/http/httptest"
+	"net/url"
 	"path/filepath"
-	"strings"
-
-	"github.com/docker/docker/api/types"
-	"github.com/sirupsen/logrus"
 )
 
-// NewMockAPIServer returns a mocked docker api server that responds to some fixed requests
-// used in the test suite.
-func NewMockAPIServer() *httptest.Server {
-	return httptest.NewServer(http.HandlerFunc(
-		func(w http.ResponseWriter, r *http.Request) {
-			logrus.Debug("Mock server has received a HTTP call on ", r.URL)
-			var response = ""
+func getMockJSONFile(relPath string) ([]byte, error) {
+	absPath, _ := filepath.Abs(relPath)
+	buf, err := ioutil.ReadFile(absPath)
+	if err != nil {
+		// logrus.WithError(err).WithField("file", absPath).Error(err)
+		return nil, err
+	}
+	return buf, nil
+}
 
-			if isRequestFor("filters=", r) {
+func RespondWithJSONFile(relPath string, statusCode int, optionalHeader ...http.Header) http.HandlerFunc {
+	handler, err := respondWithJSONFile(relPath, statusCode, optionalHeader...)
+	ExpectWithOffset(1, err).ShouldNot(HaveOccurred())
+	return handler
+}
 
-				Filters := r.URL.Query().Get("filters")
-				var result map[string]interface{}
-				_ = json.Unmarshal([]byte(Filters), &result)
-				status := result["status"].(map[string]interface{})
+func respondWithJSONFile(relPath string, statusCode int, optionalHeader ...http.Header) (http.HandlerFunc, error) {
+	buf, err := getMockJSONFile(relPath)
+	if err != nil {
+		return nil, err
+	}
+	return ghttp.RespondWith(statusCode, buf, optionalHeader...), nil
+}
+
+func GetContainerHandlers(containerFiles ...string) []http.HandlerFunc {
+	handlers := make([]http.HandlerFunc, 0, len(containerFiles)*2)
+	for _, file := range containerFiles {
+		handlers = append(handlers, getContainerHandler(file))
 
-				response = getMockJSONFromDisk("./mocks/data/containers.json")
-				var x2 []types.Container
+		// Also append the image request since that will be called for every container
+		if file == "running" {
+			// The "running" container is the only one using image02
+			handlers = append(handlers, getImageHandler(1))
+		} else {
+			handlers = append(handlers, getImageHandler(0))
+		}
+	}
+	return handlers
+}
+
+func createFilterArgs(statuses []string) filters.Args {
+	args := filters.NewArgs()
+	for _, status := range statuses {
+		args.Add("status", status)
+	}
+	return args
+}
+
+var containerFileIds = map[string]string{
+	"stopped":    "ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65",
+	"watchtower": "3d88e0e3543281c747d88b27e246578b65ae8964ba86c7cd7522cf84e0978134",
+	"running":    "b978af0b858aa8855cce46b628817d4ed58e58f2c4f66c9b9c5449134ed4c008",
+	"restarting": "ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b67",
+}
+
+var imageIds = []string{
+	"sha256:4dbc5f9c07028a985e14d1393e849ea07f68804c4293050d5a641b138db72daa",
+	"sha256:19d07168491a3f9e2798a9bed96544e34d57ddc4757a4ac5bb199dea896c87fd",
+}
+
+func getContainerHandler(file string) http.HandlerFunc {
+	id, ok := containerFileIds[file]
+	failTestUnless(ok)
+	return ghttp.CombineHandlers(
+		ghttp.VerifyRequest("GET", HaveSuffix("/containers/%v/json", id)),
+		RespondWithJSONFile(fmt.Sprintf("./mocks/data/container_%v.json", file), http.StatusOK),
+	)
+}
+
+func ListContainersHandler(statuses ...string) http.HandlerFunc {
+	filterArgs := createFilterArgs(statuses)
+	bytes, err := filterArgs.MarshalJSON()
+	ExpectWithOffset(1, err).ShouldNot(HaveOccurred())
+	query := url.Values{
+		"limit":   []string{"0"},
+		"filters": []string{string(bytes)},
+	}
+	return ghttp.CombineHandlers(
+		ghttp.VerifyRequest("GET", HaveSuffix("containers/json"), query.Encode()),
+		respondWithFilteredContainers(filterArgs),
+	)
+}
+
+func respondWithFilteredContainers(filters filters.Args) http.HandlerFunc {
+	containersJson, err := getMockJSONFile("./mocks/data/containers.json")
+	ExpectWithOffset(2, err).ShouldNot(HaveOccurred())
+	var filteredContainers []types.Container
 	var containers []types.Container
-				_ = json.Unmarshal([]byte(response), &containers)
+	ExpectWithOffset(2, json.Unmarshal(containersJson, &containers)).To(Succeed())
 	for _, v := range containers {
-					for key := range status {
+		for _, key := range filters.Get("status") {
 			if v.State == key {
-							x2 = append(x2, v)
+				filteredContainers = append(filteredContainers, v)
 			}
 		}
 	}
 
-				b, _ := json.Marshal(x2)
-				response = string(b)
-
-			} else if isRequestFor("containers/json?limit=0", r) {
-				response = getMockJSONFromDisk("./mocks/data/containers.json")
-			} else if isRequestFor("ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65", r) {
-				response = getMockJSONFromDisk("./mocks/data/container_stopped.json")
-			} else if isRequestFor("b978af0b858aa8855cce46b628817d4ed58e58f2c4f66c9b9c5449134ed4c008", r) {
-				response = getMockJSONFromDisk("./mocks/data/container_running.json")
-			} else if isRequestFor("ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b67", r) {
-				response = getMockJSONFromDisk("./mocks/data/container_restarting.json")
-			} else if isRequestFor("sha256:19d07168491a3f9e2798a9bed96544e34d57ddc4757a4ac5bb199dea896c87fd", r) {
-				response = getMockJSONFromDisk("./mocks/data/image01.json")
-			} else if isRequestFor("sha256:4dbc5f9c07028a985e14d1393e849ea07f68804c4293050d5a641b138db72daa", r) {
-				response = getMockJSONFromDisk("./mocks/data/image02.json")
-			} else if isRequestFor("containers/ex-cont-id/exec", r) {
-				response = `{"Id": "ex-exec-id"}`
-			} else if isRequestFor("exec/ex-exec-id/start", r) {
-				response = `{"Id": "ex-exec-id"}`
-			} else if isRequestFor("exec/ex-exec-id/json", r) {
-				response = `{
-    				"ExecID": "ex-exec-id",
-					"ContainerID": "ex-cont-id",
-					"Running": false,
-					"ExitCode": 0,
-					"Pid": 0
-				}`
-			} else {
-				// Allow ginkgo to correctly capture the failed assertion, even though this is called from a go func
-				defer ginkgo.GinkgoRecover()
-				ginkgo.Fail(fmt.Sprintf("mock API server endpoint not supported: %q", r.URL.String()))
-			}
-			_, _ = fmt.Fprintln(w, response)
-		},
-	))
+	return ghttp.RespondWithJSONEncoded(http.StatusOK, filteredContainers)
 }
 
-func isRequestFor(urlPart string, r *http.Request) bool {
-	return strings.Contains(r.URL.String(), urlPart)
+func getImageHandler(index int) http.HandlerFunc {
+	return ghttp.CombineHandlers(
+		ghttp.VerifyRequest("GET", HaveSuffix("/images/%v/json", imageIds[index])),
+		RespondWithJSONFile(fmt.Sprintf("./mocks/data/image%02d.json", index+1), http.StatusOK),
+	)
 }
 
-func getMockJSONFromDisk(relPath string) string {
-	absPath, _ := filepath.Abs(relPath)
-	buf, err := ioutil.ReadFile(absPath)
-	if err != nil {
-		logrus.WithError(err).WithField("file", absPath).Error(err)
-		return ""
-	}
-	return string(buf)
+func failTestUnless(ok bool) {
+	ExpectWithOffset(2, ok).To(BeTrue(), "test setup failed")
 }

pkg/container/mocks/data/container_stopped.json

@@ -21,7 +21,7 @@
   "HostnamePath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/hostname",
   "HostsPath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/hosts",
   "LogPath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65-json.log",
-  "Name": "/watchtower-test",
+  "Name": "/watchtower-stopped",
   "RestartCount": 0,
   "Driver": "overlay2",
   "Platform": "linux",

pkg/container/mocks/data/container_watchtower.json

@@ -0,0 +1,205 @@
+{
+  "Id": "3d88e0e3543281c747d88b27e246578b65ae8964ba86c7cd7522cf84e0978134",
+  "Created": "2020-04-10T19:51:22.245041005Z",
+  "Path": "/watchtower",
+  "Args": [],
+  "State": {
+    "Status": "running",
+    "Running": true,
+    "Paused": false,
+    "Restarting": false,
+    "OOMKilled": false,
+    "Dead": false,
+    "Pid": 3854,
+    "ExitCode": 0,
+    "Error": "",
+    "StartedAt": "2019-04-13T22:38:24.498745809Z",
+    "FinishedAt": "2019-04-13T22:38:18.486292076Z"
+  },
+  "Image": "sha256:4dbc5f9c07028a985e14d1393e849ea07f68804c4293050d5a641b138db72daa",
+  "ResolvConfPath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/resolv.conf",
+  "HostnamePath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/hostname",
+  "HostsPath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/hosts",
+  "LogPath": "/var/lib/docker/containers/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65/ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65-json.log",
+  "Name": "/watchtower-running",
+  "RestartCount": 0,
+  "Driver": "overlay2",
+  "Platform": "linux",
+  "MountLabel": "",
+  "ProcessLabel": "",
+  "AppArmorProfile": "",
+  "ExecIDs": null,
+  "HostConfig": {
+    "Binds": [
+      "/var/run/docker.sock:/var/run/docker.sock"
+    ],
+    "ContainerIDFile": "",
+    "LogConfig": {
+      "Type": "json-file",
+      "Config": {}
+    },
+    "NetworkMode": "default",
+    "PortBindings": {},
+    "RestartPolicy": {
+      "Name": "no",
+      "MaximumRetryCount": 0
+    },
+    "AutoRemove": false,
+    "VolumeDriver": "",
+    "VolumesFrom": null,
+    "CapAdd": null,
+    "CapDrop": null,
+    "Dns": [],
+    "DnsOptions": [],
+    "DnsSearch": [],
+    "ExtraHosts": null,
+    "GroupAdd": null,
+    "IpcMode": "shareable",
+    "Cgroup": "",
+    "Links": null,
+    "OomScoreAdj": 0,
+    "PidMode": "",
+    "Privileged": false,
+    "PublishAllPorts": false,
+    "ReadonlyRootfs": false,
+    "SecurityOpt": null,
+    "UTSMode": "",
+    "UsernsMode": "",
+    "ShmSize": 67108864,
+    "Runtime": "runc",
+    "ConsoleSize": [
+      0,
+      0
+    ],
+    "Isolation": "",
+    "CpuShares": 0,
+    "Memory": 0,
+    "NanoCpus": 0,
+    "CgroupParent": "",
+    "BlkioWeight": 0,
+    "BlkioWeightDevice": [],
+    "BlkioDeviceReadBps": null,
+    "BlkioDeviceWriteBps": null,
+    "BlkioDeviceReadIOps": null,
+    "BlkioDeviceWriteIOps": null,
+    "CpuPeriod": 0,
+    "CpuQuota": 0,
+    "CpuRealtimePeriod": 0,
+    "CpuRealtimeRuntime": 0,
+    "CpusetCpus": "",
+    "CpusetMems": "",
+    "Devices": [],
+    "DeviceCgroupRules": null,
+    "DiskQuota": 0,
+    "KernelMemory": 0,
+    "MemoryReservation": 0,
+    "MemorySwap": 0,
+    "MemorySwappiness": null,
+    "OomKillDisable": false,
+    "PidsLimit": 0,
+    "Ulimits": null,
+    "CpuCount": 0,
+    "CpuPercent": 0,
+    "IOMaximumIOps": 0,
+    "IOMaximumBandwidth": 0,
+    "MaskedPaths": [
+      "/proc/asound",
+      "/proc/acpi",
+      "/proc/kcore",
+      "/proc/keys",
+      "/proc/latency_stats",
+      "/proc/timer_list",
+      "/proc/timer_stats",
+      "/proc/sched_debug",
+      "/proc/scsi",
+      "/sys/firmware"
+    ],
+    "ReadonlyPaths": [
+      "/proc/bus",
+      "/proc/fs",
+      "/proc/irq",
+      "/proc/sys",
+      "/proc/sysrq-trigger"
+    ]
+  },
+  "GraphDriver": {
+    "Data": {
+      "LowerDir": "/var/lib/docker/overlay2/9f6b91ea6e142835035d91123bbc7a05224dfa2abd4d020eac42f2ab420ccddc-init/diff:/var/lib/docker/overlay2/cdf82f50bc49177d0c17c24f3eaa29eba607b70cc6a081f77781b21c59a13eb8/diff:/var/lib/docker/overlay2/8108325ee844603c9b08d2772cf6e65dccf31dd5171f265078e5ed79a0ba3c0f/diff:/var/lib/docker/overlay2/e5e0cce6bf91b829a308424d99d7e56a33be3a11414ff5cdc48e762a1342b20f/diff",
+      "MergedDir": "/var/lib/docker/overlay2/9f6b91ea6e142835035d91123bbc7a05224dfa2abd4d020eac42f2ab420ccddc/merged",
+      "UpperDir": "/var/lib/docker/overlay2/9f6b91ea6e142835035d91123bbc7a05224dfa2abd4d020eac42f2ab420ccddc/diff",
+      "WorkDir": "/var/lib/docker/overlay2/9f6b91ea6e142835035d91123bbc7a05224dfa2abd4d020eac42f2ab420ccddc/work"
+    },
+    "Name": "overlay2"
+  },
+  "Mounts": [
+    {
+      "Type": "bind",
+      "Source": "/var/run/docker.sock",
+      "Destination": "/var/run/docker.sock",
+      "Mode": "",
+      "RW": true,
+      "Propagation": "rprivate"
+    }
+  ],
+  "Config": {
+    "Hostname": "ae8964ba86c7",
+    "Domainname": "",
+    "User": "",
+    "AttachStdin": false,
+    "AttachStdout": true,
+    "AttachStderr": true,
+    "Tty": false,
+    "OpenStdin": false,
+    "StdinOnce": false,
+    "Env": [
+      "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+    ],
+    "Cmd": null,
+    "Image": "containrrr/watchtower:latest",
+    "Volumes": null,
+    "WorkingDir": "",
+    "Entrypoint": [
+      "/watchtower"
+    ],
+    "OnBuild": null,
+    "Labels": {
+      "com.centurylinklabs.watchtower": "true"
+    }
+  },
+  "NetworkSettings": {
+    "Bridge": "",
+    "SandboxID": "05627d36c08ed994eebc44a2a8c9365a511756b55c500fb03fd5a14477cd4bf3",
+    "HairpinMode": false,
+    "LinkLocalIPv6Address": "",
+    "LinkLocalIPv6PrefixLen": 0,
+    "Ports": {},
+    "SandboxKey": "/var/run/docker/netns/05627d36c08e",
+    "SecondaryIPAddresses": null,
+    "SecondaryIPv6Addresses": null,
+    "EndpointID": "",
+    "Gateway": "",
+    "GlobalIPv6Address": "",
+    "GlobalIPv6PrefixLen": 0,
+    "IPAddress": "",
+    "IPPrefixLen": 0,
+    "IPv6Gateway": "",
+    "MacAddress": "",
+    "Networks": {
+      "bridge": {
+        "IPAMConfig": null,
+        "Links": null,
+        "Aliases": null,
+        "NetworkID": "8fcfd56fa9203bafa98510abb08bff66ad05bef5b6e97d158cbae3397e1e065e",
+        "EndpointID": "",
+        "Gateway": "",
+        "IPAddress": "",
+        "IPPrefixLen": 0,
+        "IPv6Gateway": "",
+        "GlobalIPv6Address": "",
+        "GlobalIPv6PrefixLen": 0,
+        "MacAddress": "",
+        "DriverOpts": null
+      }
+    }
+  }
+}

pkg/container/mocks/data/containers.json

@@ -2,7 +2,7 @@
   {
     "Id": "ae8964ba86c7cd7522cf84e09781343d88e0e3543281c747d88b27e246578b65",
     "Names": [
-      "/watchtower-test"
+      "/watchtower-stopped"
     ],
     "Image": "containrrr/watchtower:latest",
     "ImageID": "sha256:4dbc5f9c07028a985e14d1393e849ea07f68804c4293050d5a641b138db72daa",
@@ -12,7 +12,7 @@
     "Labels": {
       "com.centurylinklabs.watchtower": "true"
     },
-    "State": "running",
+    "State": "exited",
     "Status": "Exited (1) 6 days ago",
     "HostConfig": {
       "NetworkMode": "default"
@@ -47,6 +47,54 @@
       }
     ]
   },
+  {
+    "Id": "3d88e0e3543281c747d88b27e246578b65ae8964ba86c7cd7522cf84e0978134",
+    "Names": [
+      "/watchtower-running"
+    ],
+    "Image": "containrrr/watchtower:latest",
+    "ImageID": "sha256:4dbc5f9c07028a985e14d1393e849ea07f68804c4293050d5a641b138db72daa",
+    "Command": "/watchtower",
+    "Created": 1554925882,
+    "Ports": [],
+    "Labels": {
+      "com.centurylinklabs.watchtower": "true"
+    },
+    "State": "running",
+    "Status": "Up 3 days",
+    "HostConfig": {
+      "NetworkMode": "default"
+    },
+    "NetworkSettings": {
+      "Networks": {
+        "bridge": {
+          "IPAMConfig": null,
+          "Links": null,
+          "Aliases": null,
+          "NetworkID": "8fcfd56fa9203bafa98510abb08bff66ad05bef5b6e97d158cbae3397e1e065e",
+          "EndpointID": "",
+          "Gateway": "",
+          "IPAddress": "",
+          "IPPrefixLen": 0,
+          "IPv6Gateway": "",
+          "GlobalIPv6Address": "",
+          "GlobalIPv6PrefixLen": 0,
+          "MacAddress": "",
+          "DriverOpts": null
+        }
+      }
+    },
+    "Mounts": [
+      {
+        "Type": "bind",
+        "Source": "/var/run/docker.sock",
+        "Destination": "/var/run/docker.sock",
+        "Mode": "",
+        "RW": true,
+        "Propagation": "rprivate"
+      }
+    ]
+  },
   {
     "Id": "b978af0b858aa8855cce46b628817d4ed58e58f2c4f66c9b9c5449134ed4c008",
     "Names": [