/* Copyright 2020 Docker, Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package main import ( "context" "errors" "fmt" "io/ioutil" "net/http" "net/url" "os" "runtime" "strconv" "strings" "syscall" "testing" "time" "github.com/docker/compose-cli/aci/convert" "gotest.tools/v3/assert" is "gotest.tools/v3/assert/cmp" "gotest.tools/v3/icmd" "gotest.tools/v3/poll" "github.com/Azure/azure-sdk-for-go/profiles/2019-03-01/resources/mgmt/resources" azure_storage "github.com/Azure/azure-sdk-for-go/profiles/2019-03-01/storage/mgmt/storage" "github.com/Azure/azure-storage-file-go/azfile" "github.com/Azure/go-autorest/autorest/to" "github.com/docker/compose-cli/aci" "github.com/docker/compose-cli/aci/login" "github.com/docker/compose-cli/containers" "github.com/docker/compose-cli/context/store" "github.com/docker/compose-cli/errdefs" "github.com/docker/compose-cli/tests/aci-e2e/storage" . "github.com/docker/compose-cli/tests/framework" ) const ( contextName = "aci-test" location = "eastus2" ) var binDir string func TestMain(m *testing.M) { p, cleanup, err := SetupExistingCLI() if err != nil { fmt.Println(err) os.Exit(1) } binDir = p exitCode := m.Run() cleanup() os.Exit(exitCode) } // Cannot be parallelized as login/logout is global. func TestLoginLogout(t *testing.T) { startTime := strconv.Itoa(int(time.Now().UnixNano())) c := NewE2eCLI(t, binDir) rg := "E2E-" + startTime t.Run("login", func(t *testing.T) { azureLogin(t, c) }) t.Run("create context", func(t *testing.T) { sID := getSubscriptionID(t) err := createResourceGroup(t, sID, rg) assert.Check(t, is.Nil(err)) t.Cleanup(func() { _ = deleteResourceGroup(t, rg) }) c.RunDockerCmd("context", "create", "aci", contextName, "--subscription-id", sID, "--resource-group", rg, "--location", location) res := c.RunDockerCmd("context", "use", contextName) res.Assert(t, icmd.Expected{Out: contextName}) res = c.RunDockerCmd("context", "ls") res.Assert(t, icmd.Expected{Out: contextName + " *"}) }) t.Run("delete context", func(t *testing.T) { res := c.RunDockerCmd("context", "use", "default") res.Assert(t, icmd.Expected{Out: "default"}) res = c.RunDockerCmd("context", "rm", contextName) res.Assert(t, icmd.Expected{Out: contextName}) }) t.Run("logout", func(t *testing.T) { _, err := os.Stat(login.GetTokenStorePath()) assert.NilError(t, err) res := c.RunDockerCmd("logout", "azure") res.Assert(t, icmd.Expected{Out: "Removing login credentials for Azure"}) _, err = os.Stat(login.GetTokenStorePath()) errMsg := "no such file or directory" if runtime.GOOS == "windows" { errMsg = "The system cannot find the file specified" } assert.ErrorContains(t, err, errMsg) }) t.Run("create context fail", func(t *testing.T) { res := c.RunDockerOrExitError("context", "create", "aci", "fail-context") res.Assert(t, icmd.Expected{ ExitCode: errdefs.ExitCodeLoginRequired, Err: `not logged in to azure, you need to run "docker login azure" first`, }) }) } func TestContainerRunVolume(t *testing.T) { c := NewParallelE2eCLI(t, binDir) sID, rg := setupTestResourceGroup(t, c) const ( testShareName = "dockertestshare" testFileContent = "Volume mounted successfully!" testFileName = "index.html" ) // Bootstrap volume aciContext := store.AciContext{ SubscriptionID: sID, Location: location, ResourceGroup: rg, } saName := "e2e" + strconv.Itoa(int(time.Now().UnixNano())) _, cleanupSa := createStorageAccount(t, aciContext, saName) t.Cleanup(func() { if err := cleanupSa(); err != nil { t.Error(err) } }) keys := getStorageKeys(t, aciContext, saName) assert.Assert(t, len(keys) > 0) k := *keys[0].Value cred, u := createFileShare(t, k, testShareName, saName) uploadFile(t, *cred, u.String(), testFileName, testFileContent) // Used in subtests var ( container string hostIP string endpoint string ) t.Run("run", func(t *testing.T) { mountTarget := "/usr/share/nginx/html" res := c.RunDockerCmd( "run", "-d", "-v", fmt.Sprintf("%s@%s:%s", saName, testShareName, mountTarget), "-p", "80:80", "nginx", ) container = getContainerName(res.Stdout()) }) t.Run("inspect", func(t *testing.T) { res := c.RunDockerCmd("inspect", container) containerInspect, err := ParseContainerInspect(res.Stdout()) assert.NilError(t, err) assert.Equal(t, containerInspect.Platform, "Linux") assert.Equal(t, containerInspect.CPULimit, 1.0) assert.Equal(t, containerInspect.RestartPolicyCondition, containers.RestartPolicyNone) assert.Assert(t, is.Len(containerInspect.Ports, 1)) hostIP = containerInspect.Ports[0].HostIP endpoint = fmt.Sprintf("http://%s:%d", containerInspect.Ports[0].HostIP, containerInspect.Ports[0].HostPort) }) t.Run("ps", func(t *testing.T) { res := c.RunDockerCmd("ps") out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") l := out[len(out)-1] assert.Assert(t, strings.Contains(l, container), "Looking for %q in line: %s", container, l) assert.Assert(t, strings.Contains(l, "nginx")) assert.Assert(t, strings.Contains(l, "Running")) assert.Assert(t, strings.Contains(l, hostIP+":80->80/tcp")) }) t.Run("http get", func(t *testing.T) { r, err := http.Get(endpoint) assert.NilError(t, err) assert.Equal(t, r.StatusCode, http.StatusOK) b, err := ioutil.ReadAll(r.Body) assert.NilError(t, err) assert.Assert(t, strings.Contains(string(b), testFileContent), "Actual content: "+string(b)) }) t.Run("logs", func(t *testing.T) { res := c.RunDockerCmd("logs", container) res.Assert(t, icmd.Expected{Out: "GET"}) }) t.Run("exec", func(t *testing.T) { res := c.RunDockerCmd("exec", container, "pwd") res.Assert(t, icmd.Expected{Out: "/"}) res = c.RunDockerOrExitError("exec", container, "echo", "fail_with_argument") res.Assert(t, icmd.Expected{ ExitCode: 1, Err: "ACI exec command does not accept arguments to the command. Only the binary should be specified", }) }) t.Run("logs follow", func(t *testing.T) { cmd := c.NewDockerCmd("logs", "--follow", container) res := icmd.StartCmd(cmd) checkUp := func(t poll.LogT) poll.Result { r, _ := http.Get(endpoint + "/is_up") if r != nil && r.StatusCode == http.StatusNotFound { return poll.Success() } return poll.Continue("waiting for container to serve request") } poll.WaitOn(t, checkUp, poll.WithDelay(1*time.Second), poll.WithTimeout(60*time.Second)) assert.Assert(t, !strings.Contains(res.Stdout(), "/test")) checkLogs := func(t poll.LogT) poll.Result { if strings.Contains(res.Stdout(), "/test") { return poll.Success() } return poll.Continue("waiting for logs to contain /test") } // Do request on /test go func() { time.Sleep(3 * time.Second) _, _ = http.Get(endpoint + "/test") }() poll.WaitOn(t, checkLogs, poll.WithDelay(3*time.Second), poll.WithTimeout(20*time.Second)) if runtime.GOOS == "windows" { err := res.Cmd.Process.Kill() assert.NilError(t, err) } else { err := res.Cmd.Process.Signal(syscall.SIGTERM) assert.NilError(t, err) } }) t.Run("rm a running container", func(t *testing.T) { res := c.RunDockerOrExitError("rm", container) res.Assert(t, icmd.Expected{ Err: fmt.Sprintf("Error: you cannot remove a running container %s. Stop the container before attempting removal or force remove", container), ExitCode: 1, }) }) t.Run("force rm", func(t *testing.T) { res := c.RunDockerCmd("rm", "-f", container) res.Assert(t, icmd.Expected{Out: container}) checkStopped := func(t poll.LogT) poll.Result { res := c.RunDockerOrExitError("inspect", container) if res.ExitCode == 1 { return poll.Success() } return poll.Continue("waiting for container to stop") } poll.WaitOn(t, checkStopped, poll.WithDelay(5*time.Second), poll.WithTimeout(60*time.Second)) }) } func TestContainerRunAttached(t *testing.T) { c := NewParallelE2eCLI(t, binDir) _, _ = setupTestResourceGroup(t, c) // Used in subtests var ( container string endpoint string ) container = "test-container" var followLogsProcess *icmd.Result t.Run("run attached limits", func(t *testing.T) { cmd := c.NewDockerCmd( "run", "--name", container, "--restart", "on-failure", "--memory", "0.1G", "--cpus", "0.1", "-p", "80:80", "nginx", ) followLogsProcess = icmd.StartCmd(cmd) checkRunning := func(t poll.LogT) poll.Result { res := c.RunDockerOrExitError("inspect", container) if res.ExitCode == 0 { return poll.Success() } return poll.Continue("waiting for container to be running") } poll.WaitOn(t, checkRunning, poll.WithDelay(5*time.Second), poll.WithTimeout(60*time.Second)) inspectRes := c.RunDockerCmd("inspect", container) containerInspect, err := ParseContainerInspect(inspectRes.Stdout()) assert.NilError(t, err) assert.Equal(t, containerInspect.Platform, "Linux") assert.Equal(t, containerInspect.CPULimit, 0.1) assert.Equal(t, containerInspect.MemoryLimit, uint64(107374182)) assert.Equal(t, containerInspect.RestartPolicyCondition, containers.RestartPolicyOnFailure) assert.Assert(t, is.Len(containerInspect.Ports, 1)) port := containerInspect.Ports[0] assert.Assert(t, len(port.HostIP) > 0) assert.Equal(t, port.ContainerPort, uint32(80)) assert.Equal(t, port.HostPort, uint32(80)) endpoint = fmt.Sprintf("http://%s:%d", port.HostIP, port.HostPort) assert.Assert(t, !strings.Contains(followLogsProcess.Stdout(), "/test")) checkRequest := func(t poll.LogT) poll.Result { r, _ := http.Get(endpoint + "/test") if r != nil && r.StatusCode == http.StatusNotFound { return poll.Success() } return poll.Continue("waiting for container to serve request") } poll.WaitOn(t, checkRequest, poll.WithDelay(1*time.Second), poll.WithTimeout(60*time.Second)) checkLog := func(t poll.LogT) poll.Result { if strings.Contains(followLogsProcess.Stdout(), "/test") { return poll.Success() } return poll.Continue("waiting for logs to contain /test") } poll.WaitOn(t, checkLog, poll.WithDelay(1*time.Second), poll.WithTimeout(20*time.Second)) }) t.Run("stop wrong container", func(t *testing.T) { res := c.RunDockerOrExitError("stop", "unknown-container") res.Assert(t, icmd.Expected{ Err: "Error: container unknown-container not found", ExitCode: 1, }) }) t.Run("stop container", func(t *testing.T) { res := c.RunDockerCmd("stop", container) res.Assert(t, icmd.Expected{Out: container}) waitForStatus(t, c, container, "Terminated", "Node Stopped") }) t.Run("check we stoppped following logs", func(t *testing.T) { // nolint errcheck followLogsStopped := waitWithTimeout(func() { followLogsProcess.Cmd.Process.Wait() }, 10*time.Second) assert.NilError(t, followLogsStopped, "Follow logs process did not stop after container is stopped") }) t.Run("ps stopped container with --all", func(t *testing.T) { res := c.RunDockerCmd("ps", container) out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") assert.Assert(t, is.Len(out, 1)) res = c.RunDockerCmd("ps", "--all", container) out = strings.Split(strings.TrimSpace(res.Stdout()), "\n") assert.Assert(t, is.Len(out, 2)) }) t.Run("restart container", func(t *testing.T) { res := c.RunDockerCmd("start", container) res.Assert(t, icmd.Expected{Out: container}) waitForStatus(t, c, container, convert.StatusRunning) }) t.Run("kill & rm stopped container", func(t *testing.T) { res := c.RunDockerCmd("kill", container) res.Assert(t, icmd.Expected{Out: container}) waitForStatus(t, c, container, "Terminated", "Node Stopped") res = c.RunDockerCmd("rm", container) res.Assert(t, icmd.Expected{Out: container}) }) } func TestComposeUpUpdate(t *testing.T) { c := NewParallelE2eCLI(t, binDir) _, _ = setupTestResourceGroup(t, c) const ( composeFile = "../composefiles/aci-demo/aci_demo_port.yaml" composeFileMultiplePorts = "../composefiles/aci-demo/aci_demo_multi_port.yaml" composeProjectName = "acidemo" serverContainer = composeProjectName + "_web" wordsContainer = composeProjectName + "_words" dbContainer = composeProjectName + "_db" ) t.Run("compose up", func(t *testing.T) { // Name of Compose project is taken from current folder "acie2e" c.RunDockerCmd("compose", "up", "-f", composeFile) res := c.RunDockerCmd("ps") out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") // Check three containers are running assert.Assert(t, is.Len(out, 4)) webRunning := false for _, l := range out { if strings.Contains(l, serverContainer) { webRunning = true strings.Contains(l, ":80->80/tcp") } } assert.Assert(t, webRunning, "web container not running") res = c.RunDockerCmd("inspect", serverContainer) containerInspect, err := ParseContainerInspect(res.Stdout()) assert.NilError(t, err) assert.Assert(t, is.Len(containerInspect.Ports, 1)) endpoint := fmt.Sprintf("http://%s:%d", containerInspect.Ports[0].HostIP, containerInspect.Ports[0].HostPort) r, err := http.Get(endpoint + "/words/noun") assert.NilError(t, err) assert.Equal(t, r.StatusCode, http.StatusOK) b, err := ioutil.ReadAll(r.Body) assert.NilError(t, err) assert.Assert(t, strings.Contains(string(b), `"word":`)) }) t.Run("compose ps", func(t *testing.T) { res := c.RunDockerCmd("compose", "ps", "--project-name", composeProjectName) lines := strings.Split(strings.TrimSpace(res.Stdout()), "\n") assert.Assert(t, is.Len(lines, 4)) var wordsDisplayed, webDisplayed, dbDisplayed bool for _, line := range lines { fields := strings.Fields(line) containerID := fields[0] switch containerID { case wordsContainer: wordsDisplayed = true assert.DeepEqual(t, fields, []string{containerID, "words", "1/1"}) case dbContainer: dbDisplayed = true assert.DeepEqual(t, fields, []string{containerID, "db", "1/1"}) case serverContainer: webDisplayed = true assert.Equal(t, fields[1], "web") assert.Check(t, strings.Contains(fields[3], ":80->80/tcp")) } } assert.Check(t, webDisplayed && wordsDisplayed && dbDisplayed, "\n%s\n", res.Stdout()) }) t.Run("logs web", func(t *testing.T) { res := c.RunDockerCmd("logs", serverContainer) res.Assert(t, icmd.Expected{Out: "Listening on port 80"}) }) t.Run("update", func(t *testing.T) { c.RunDockerCmd("compose", "up", "-f", composeFileMultiplePorts, "--project-name", composeProjectName) res := c.RunDockerCmd("ps") out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") // Check three containers are running assert.Assert(t, is.Len(out, 4)) for _, cName := range []string{serverContainer, wordsContainer} { res = c.RunDockerCmd("inspect", cName) containerInspect, err := ParseContainerInspect(res.Stdout()) assert.NilError(t, err) assert.Assert(t, is.Len(containerInspect.Ports, 1)) endpoint := fmt.Sprintf("http://%s:%d", containerInspect.Ports[0].HostIP, containerInspect.Ports[0].HostPort) var route string switch cName { case serverContainer: route = "/words/noun" assert.Equal(t, containerInspect.Ports[0].HostPort, uint32(80)) assert.Equal(t, containerInspect.Ports[0].ContainerPort, uint32(80)) case wordsContainer: route = "/noun" assert.Equal(t, containerInspect.Ports[0].HostPort, uint32(8080)) assert.Equal(t, containerInspect.Ports[0].ContainerPort, uint32(8080)) } checkUp := func(t poll.LogT) poll.Result { r, _ := http.Get(endpoint + route) if r != nil && r.StatusCode == http.StatusOK { return poll.Success() } return poll.Continue("Waiting for container to serve request") } poll.WaitOn(t, checkUp, poll.WithDelay(1*time.Second), poll.WithTimeout(60*time.Second)) res = c.RunDockerCmd("ps") p := containerInspect.Ports[0] res.Assert(t, icmd.Expected{ Out: fmt.Sprintf("%s:%d->%d/tcp", p.HostIP, p.HostPort, p.ContainerPort), }) } }) t.Run("down", func(t *testing.T) { c.RunDockerCmd("compose", "down", "--project-name", composeProjectName) res := c.RunDockerCmd("ps") out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") assert.Equal(t, len(out), 1) }) } func TestRunEnvVars(t *testing.T) { c := NewParallelE2eCLI(t, binDir) _, _ = setupTestResourceGroup(t, c) t.Run("run", func(t *testing.T) { cmd := c.NewDockerCmd( "run", "-d", "-e", "MYSQL_ROOT_PASSWORD=rootpwd", "-e", "MYSQL_DATABASE=mytestdb", "-e", "MYSQL_USER", "-e", "MYSQL_PASSWORD=userpwd", "mysql:5.7", ) cmd.Env = append(cmd.Env, "MYSQL_USER=user1") res := icmd.RunCmd(cmd) res.Assert(t, icmd.Success) out := strings.Split(strings.TrimSpace(res.Stdout()), "\n") container := strings.TrimSpace(out[len(out)-1]) res = c.RunDockerCmd("inspect", container) containerInspect, err := ParseContainerInspect(res.Stdout()) assert.NilError(t, err) assert.Equal(t, containerInspect.Image, "mysql:5.7") check := func(t poll.LogT) poll.Result { res := c.RunDockerOrExitError("logs", container) if strings.Contains(res.Stdout(), "Giving user user1 access to schema mytestdb") { return poll.Success() } return poll.Continue("waiting for DB container to be up") } poll.WaitOn(t, check, poll.WithDelay(5*time.Second), poll.WithTimeout(60*time.Second)) }) } func setupTestResourceGroup(t *testing.T, c *E2eCLI) (string, string) { startTime := strconv.Itoa(int(time.Now().Unix())) rg := "E2E-" + t.Name() + "-" + startTime azureLogin(t, c) sID := getSubscriptionID(t) err := createResourceGroup(t, sID, rg) assert.Check(t, is.Nil(err)) t.Cleanup(func() { if err := deleteResourceGroup(t, rg); err != nil { t.Error(err) } }) createAciContextAndUseIt(t, c, sID, rg) // Check nothing is running res := c.RunDockerCmd("ps") assert.Assert(t, is.Len(strings.Split(strings.TrimSpace(res.Stdout()), "\n"), 1)) return sID, rg } func deleteResourceGroup(t *testing.T, rgName string) error { fmt.Printf(" [%s] deleting resource group %s\n", t.Name(), rgName) ctx := context.TODO() helper := aci.NewACIResourceGroupHelper() models, err := helper.GetSubscriptionIDs(ctx) if err != nil { return err } if len(models) == 0 { return errors.New("unable to delete resource group: no models") } return helper.DeleteAsync(ctx, *models[0].SubscriptionID, rgName) } func azureLogin(t *testing.T, c *E2eCLI) { // in order to create new service principal and get these 3 values : `az ad sp create-for-rbac --name 'TestServicePrincipal' --sdk-auth` clientID := os.Getenv("AZURE_CLIENT_ID") clientSecret := os.Getenv("AZURE_CLIENT_SECRET") tenantID := os.Getenv("AZURE_TENANT_ID") assert.Check(t, clientID != "", "AZURE_CLIENT_ID must not be empty") assert.Check(t, clientSecret != "", "AZURE_CLIENT_SECRET must not be empty") assert.Check(t, tenantID != "", "AZURE_TENANT_ID must not be empty") c.RunDockerCmd("login", "azure", "--client-id", clientID, "--client-secret", clientSecret, "--tenant-id", tenantID) } func getSubscriptionID(t *testing.T) string { ctx := context.TODO() helper := aci.NewACIResourceGroupHelper() models, err := helper.GetSubscriptionIDs(ctx) assert.Check(t, is.Nil(err)) assert.Check(t, len(models) == 1) return *models[0].SubscriptionID } func createResourceGroup(t *testing.T, sID, rgName string) error { fmt.Printf(" [%s] creating resource group %s\n", t.Name(), rgName) helper := aci.NewACIResourceGroupHelper() _, err := helper.CreateOrUpdate(context.TODO(), sID, rgName, resources.Group{Location: to.StringPtr(location)}) return err } func createAciContextAndUseIt(t *testing.T, c *E2eCLI, sID, rgName string) { res := c.RunDockerCmd("context", "create", "aci", contextName, "--subscription-id", sID, "--resource-group", rgName, "--location", location) res.Assert(t, icmd.Expected{Out: "Successfully created aci context \"" + contextName + "\""}) res = c.RunDockerCmd("context", "use", contextName) res.Assert(t, icmd.Expected{Out: contextName}) res = c.RunDockerCmd("context", "ls") res.Assert(t, icmd.Expected{Out: contextName + " *"}) } func createStorageAccount(t *testing.T, aciContext store.AciContext, name string) (azure_storage.Account, func() error) { account, err := storage.CreateStorageAccount(context.TODO(), aciContext, name) assert.Check(t, is.Nil(err)) assert.Check(t, is.Equal(*(account.Name), name)) return account, func() error { return deleteStorageAccount(aciContext, name) } } func deleteStorageAccount(aciContext store.AciContext, name string) error { _, err := storage.DeleteStorageAccount(context.TODO(), aciContext, name) return err } func getStorageKeys(t *testing.T, aciContext store.AciContext, saName string) []azure_storage.AccountKey { l, err := storage.ListKeys(context.TODO(), aciContext, saName) assert.NilError(t, err) assert.Assert(t, l.Keys != nil) return *l.Keys } func createFileShare(t *testing.T, key, share, storageAccount string) (*azfile.SharedKeyCredential, *url.URL) { // Create a ShareURL object that wraps a soon-to-be-created share's URL and a default pipeline. u, _ := url.Parse(fmt.Sprintf("https://%s.file.core.windows.net/%s", storageAccount, share)) cred, err := azfile.NewSharedKeyCredential(storageAccount, key) assert.NilError(t, err) shareURL := azfile.NewShareURL(*u, azfile.NewPipeline(cred, azfile.PipelineOptions{})) _, err = shareURL.Create(context.TODO(), azfile.Metadata{}, 0) assert.NilError(t, err) return cred, u } func uploadFile(t *testing.T, cred azfile.SharedKeyCredential, baseURL, fileName, content string) { fURL, err := url.Parse(baseURL + "/" + fileName) assert.NilError(t, err) fileURL := azfile.NewFileURL(*fURL, azfile.NewPipeline(&cred, azfile.PipelineOptions{})) err = azfile.UploadBufferToAzureFile(context.TODO(), []byte(content), fileURL, azfile.UploadToAzureFileOptions{}) assert.NilError(t, err) } func getContainerName(stdout string) string { out := strings.Split(strings.TrimSpace(stdout), "\n") return strings.TrimSpace(out[len(out)-1]) } func waitForStatus(t *testing.T, c *E2eCLI, containerID string, statuses ...string) { checkStopped := func(logt poll.LogT) poll.Result { res := c.RunDockerCmd("inspect", containerID) containerInspect, err := ParseContainerInspect(res.Stdout()) assert.NilError(t, err) for _, status := range statuses { if containerInspect.Status == status { return poll.Success() } } return poll.Continue("Status %s != %s (expected) for container %s", containerInspect.Status, statuses, containerID) } poll.WaitOn(t, checkStopped, poll.WithDelay(5*time.Second), poll.WithTimeout(90*time.Second)) } func waitWithTimeout(blockingCall func(), timeout time.Duration) error { c := make(chan struct{}) go func() { defer close(c) blockingCall() }() select { case <-c: return nil case <-time.After(timeout): return fmt.Errorf("Timed out after %s", timeout) } }