package docker import ( "bufio" "fmt" "io" "io/ioutil" "math/rand" "os" "regexp" "sort" "strings" "testing" "time" ) func TestIdFormat(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container1, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/sh", "-c", "echo hello world"}, }, ) if err != nil { t.Fatal(err) } match, err := regexp.Match("^[0-9a-f]{64}$", []byte(container1.Id)) if err != nil { t.Fatal(err) } if !match { t.Fatalf("Invalid container ID: %s", container1.Id) } } func TestMultipleAttachRestart(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/sh", "-c", "i=1; while [ $i -le 5 ]; do i=`expr $i + 1`; echo hello; done"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) // Simulate 3 client attaching to the container and stop/restart stdout1, err := container.StdoutPipe() if err != nil { t.Fatal(err) } stdout2, err := container.StdoutPipe() if err != nil { t.Fatal(err) } stdout3, err := container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } l1, err := bufio.NewReader(stdout1).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l1, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l1) } l2, err := bufio.NewReader(stdout2).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l2, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l2) } l3, err := bufio.NewReader(stdout3).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l3, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l3) } if err := container.Stop(10); err != nil { t.Fatal(err) } stdout1, err = container.StdoutPipe() if err != nil { t.Fatal(err) } stdout2, err = container.StdoutPipe() if err != nil { t.Fatal(err) } stdout3, err = container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } setTimeout(t, "Timeout reading from the process", 3*time.Second, func() { l1, err = bufio.NewReader(stdout1).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l1, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l1) } l2, err = bufio.NewReader(stdout2).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l2, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l2) } l3, err = bufio.NewReader(stdout3).ReadString('\n') if err != nil { t.Fatal(err) } if strings.Trim(l3, " \r\n") != "hello" { t.Fatalf("Unexpected output. Expected [%s], received [%s]", "hello", l3) } }) container.Wait() } func TestDiff(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) // Create a container and remove a file container1, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/rm", "/etc/passwd"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container1) if err := container1.Run(); err != nil { t.Fatal(err) } // Check the changelog c, err := container1.Changes() if err != nil { t.Fatal(err) } success := false for _, elem := range c { if elem.Path == "/etc/passwd" && elem.Kind == 2 { success = true } } if !success { t.Fatalf("/etc/passwd as been removed but is not present in the diff") } // Commit the container rwTar, err := container1.ExportRw() if err != nil { t.Error(err) } img, err := runtime.graph.Create(rwTar, container1, "unit test commited image - diff", "", nil) if err != nil { t.Error(err) } // Create a new container from the commited image container2, err := runtime.Create( &Config{ Image: img.Id, Cmd: []string{"cat", "/etc/passwd"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container2) if err := container2.Run(); err != nil { t.Fatal(err) } // Check the changelog c, err = container2.Changes() if err != nil { t.Fatal(err) } for _, elem := range c { if elem.Path == "/etc/passwd" { t.Fatalf("/etc/passwd should not be present in the diff after commit.") } } } func TestCommitAutoRun(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container1, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/sh", "-c", "echo hello > /world"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container1) if container1.State.Running { t.Errorf("Container shouldn't be running") } if err := container1.Run(); err != nil { t.Fatal(err) } if container1.State.Running { t.Errorf("Container shouldn't be running") } rwTar, err := container1.ExportRw() if err != nil { t.Error(err) } img, err := runtime.graph.Create(rwTar, container1, "unit test commited image", "", &Config{Cmd: []string{"cat", "/world"}}) if err != nil { t.Error(err) } // FIXME: Make a TestCommit that stops here and check docker.root/layers/img.id/world container2, err := runtime.Create( &Config{ Image: img.Id, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container2) stdout, err := container2.StdoutPipe() if err != nil { t.Fatal(err) } stderr, err := container2.StderrPipe() if err != nil { t.Fatal(err) } if err := container2.Start(); err != nil { t.Fatal(err) } container2.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } output2, err := ioutil.ReadAll(stderr) if err != nil { t.Fatal(err) } if err := stdout.Close(); err != nil { t.Fatal(err) } if err := stderr.Close(); err != nil { t.Fatal(err) } if string(output) != "hello\n" { t.Fatalf("Unexpected output. Expected %s, received: %s (err: %s)", "hello\n", output, output2) } } func TestCommitRun(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container1, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/sh", "-c", "echo hello > /world"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container1) if container1.State.Running { t.Errorf("Container shouldn't be running") } if err := container1.Run(); err != nil { t.Fatal(err) } if container1.State.Running { t.Errorf("Container shouldn't be running") } rwTar, err := container1.ExportRw() if err != nil { t.Error(err) } img, err := runtime.graph.Create(rwTar, container1, "unit test commited image", "", nil) if err != nil { t.Error(err) } // FIXME: Make a TestCommit that stops here and check docker.root/layers/img.id/world container2, err := runtime.Create( &Config{ Image: img.Id, Cmd: []string{"cat", "/world"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container2) stdout, err := container2.StdoutPipe() if err != nil { t.Fatal(err) } stderr, err := container2.StderrPipe() if err != nil { t.Fatal(err) } if err := container2.Start(); err != nil { t.Fatal(err) } container2.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } output2, err := ioutil.ReadAll(stderr) if err != nil { t.Fatal(err) } if err := stdout.Close(); err != nil { t.Fatal(err) } if err := stderr.Close(); err != nil { t.Fatal(err) } if string(output) != "hello\n" { t.Fatalf("Unexpected output. Expected %s, received: %s (err: %s)", "hello\n", output, output2) } } func TestStart(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Memory: 33554432, Cmd: []string{"/bin/cat"}, OpenStdin: true, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) if err := container.Start(); err != nil { t.Fatal(err) } // Give some time to the process to start container.WaitTimeout(500 * time.Millisecond) if !container.State.Running { t.Errorf("Container should be running") } if err := container.Start(); err == nil { t.Fatalf("A running containter should be able to be started") } // Try to avoid the timeoout in destroy. Best effort, don't check error cStdin, _ := container.StdinPipe() cStdin.Close() container.WaitTimeout(2 * time.Second) } func TestRun(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"ls", "-al"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) if container.State.Running { t.Errorf("Container shouldn't be running") } if err := container.Run(); err != nil { t.Fatal(err) } if container.State.Running { t.Errorf("Container shouldn't be running") } } func TestOutput(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create( &Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"echo", "-n", "foobar"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err := container.Output() if err != nil { t.Fatal(err) } if string(output) != "foobar" { t.Error(string(output)) } } func TestKillDifferentUser(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"tail", "-f", "/etc/resolv.conf"}, User: "daemon", }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) if container.State.Running { t.Errorf("Container shouldn't be running") } if err := container.Start(); err != nil { t.Fatal(err) } // Give some time to lxc to spawn the process (setuid might take some time) container.WaitTimeout(500 * time.Millisecond) if !container.State.Running { t.Errorf("Container should be running") } if err := container.Kill(); err != nil { t.Fatal(err) } if container.State.Running { t.Errorf("Container shouldn't be running") } container.Wait() if container.State.Running { t.Errorf("Container shouldn't be running") } // Try stopping twice if err := container.Kill(); err != nil { t.Fatal(err) } } func TestKill(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat", "/dev/zero"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) if container.State.Running { t.Errorf("Container shouldn't be running") } if err := container.Start(); err != nil { t.Fatal(err) } // Give some time to lxc to spawn the process container.WaitTimeout(500 * time.Millisecond) if !container.State.Running { t.Errorf("Container should be running") } if err := container.Kill(); err != nil { t.Fatal(err) } if container.State.Running { t.Errorf("Container shouldn't be running") } container.Wait() if container.State.Running { t.Errorf("Container shouldn't be running") } // Try stopping twice if err := container.Kill(); err != nil { t.Fatal(err) } } func TestExitCode(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) trueContainer, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/true", ""}, }) if err != nil { t.Fatal(err) } defer runtime.Destroy(trueContainer) if err := trueContainer.Run(); err != nil { t.Fatal(err) } if trueContainer.State.ExitCode != 0 { t.Errorf("Unexpected exit code %d (expected 0)", trueContainer.State.ExitCode) } falseContainer, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/false", ""}, }) if err != nil { t.Fatal(err) } defer runtime.Destroy(falseContainer) if err := falseContainer.Run(); err != nil { t.Fatal(err) } if falseContainer.State.ExitCode != 1 { t.Errorf("Unexpected exit code %d (expected 1)", falseContainer.State.ExitCode) } } func TestRestart(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"echo", "-n", "foobar"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err := container.Output() if err != nil { t.Fatal(err) } if string(output) != "foobar" { t.Error(string(output)) } // Run the container again and check the output output, err = container.Output() if err != nil { t.Fatal(err) } if string(output) != "foobar" { t.Error(string(output)) } } func TestRestartStdin(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat"}, OpenStdin: true, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) stdin, err := container.StdinPipe() if err != nil { t.Fatal(err) } stdout, err := container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } if _, err := io.WriteString(stdin, "hello world"); err != nil { t.Fatal(err) } if err := stdin.Close(); err != nil { t.Fatal(err) } container.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } if err := stdout.Close(); err != nil { t.Fatal(err) } if string(output) != "hello world" { t.Fatalf("Unexpected output. Expected %s, received: %s", "hello world", string(output)) } // Restart and try again stdin, err = container.StdinPipe() if err != nil { t.Fatal(err) } stdout, err = container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } if _, err := io.WriteString(stdin, "hello world #2"); err != nil { t.Fatal(err) } if err := stdin.Close(); err != nil { t.Fatal(err) } container.Wait() output, err = ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } if err := stdout.Close(); err != nil { t.Fatal(err) } if string(output) != "hello world #2" { t.Fatalf("Unexpected output. Expected %s, received: %s", "hello world #2", string(output)) } } func TestUser(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) // Default user must be root container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"id"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err := container.Output() if err != nil { t.Fatal(err) } if !strings.Contains(string(output), "uid=0(root) gid=0(root)") { t.Error(string(output)) } // Set a username container, err = runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"id"}, User: "root", }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err = container.Output() if err != nil || container.State.ExitCode != 0 { t.Fatal(err) } if !strings.Contains(string(output), "uid=0(root) gid=0(root)") { t.Error(string(output)) } // Set a UID container, err = runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"id"}, User: "0", }, ) if err != nil || container.State.ExitCode != 0 { t.Fatal(err) } defer runtime.Destroy(container) output, err = container.Output() if err != nil || container.State.ExitCode != 0 { t.Fatal(err) } if !strings.Contains(string(output), "uid=0(root) gid=0(root)") { t.Error(string(output)) } // Set a different user by uid container, err = runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"id"}, User: "1", }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err = container.Output() if err != nil { t.Fatal(err) } else if container.State.ExitCode != 0 { t.Fatalf("Container exit code is invalid: %d\nOutput:\n%s\n", container.State.ExitCode, output) } if !strings.Contains(string(output), "uid=1(daemon) gid=1(daemon)") { t.Error(string(output)) } // Set a different user by username container, err = runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"id"}, User: "daemon", }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) output, err = container.Output() if err != nil || container.State.ExitCode != 0 { t.Fatal(err) } if !strings.Contains(string(output), "uid=1(daemon) gid=1(daemon)") { t.Error(string(output)) } } func TestMultipleContainers(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container1, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat", "/dev/zero"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container1) container2, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat", "/dev/zero"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container2) // Start both containers if err := container1.Start(); err != nil { t.Fatal(err) } if err := container2.Start(); err != nil { t.Fatal(err) } // Make sure they are running before trying to kill them container1.WaitTimeout(250 * time.Millisecond) container2.WaitTimeout(250 * time.Millisecond) // If we are here, both containers should be running if !container1.State.Running { t.Fatal("Container not running") } if !container2.State.Running { t.Fatal("Container not running") } // Kill them if err := container1.Kill(); err != nil { t.Fatal(err) } if err := container2.Kill(); err != nil { t.Fatal(err) } } func TestStdin(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat"}, OpenStdin: true, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) stdin, err := container.StdinPipe() if err != nil { t.Fatal(err) } stdout, err := container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } defer stdin.Close() defer stdout.Close() if _, err := io.WriteString(stdin, "hello world"); err != nil { t.Fatal(err) } if err := stdin.Close(); err != nil { t.Fatal(err) } container.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } if string(output) != "hello world" { t.Fatalf("Unexpected output. Expected %s, received: %s", "hello world", string(output)) } } func TestTty(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"cat"}, OpenStdin: true, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) stdin, err := container.StdinPipe() if err != nil { t.Fatal(err) } stdout, err := container.StdoutPipe() if err != nil { t.Fatal(err) } if err := container.Start(); err != nil { t.Fatal(err) } defer stdin.Close() defer stdout.Close() if _, err := io.WriteString(stdin, "hello world"); err != nil { t.Fatal(err) } if err := stdin.Close(); err != nil { t.Fatal(err) } container.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } if string(output) != "hello world" { t.Fatalf("Unexpected output. Expected %s, received: %s", "hello world", string(output)) } } func TestEnv(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/usr/bin/env"}, }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) stdout, err := container.StdoutPipe() if err != nil { t.Fatal(err) } defer stdout.Close() if err := container.Start(); err != nil { t.Fatal(err) } container.Wait() output, err := ioutil.ReadAll(stdout) if err != nil { t.Fatal(err) } actualEnv := strings.Split(string(output), "\n") if actualEnv[len(actualEnv)-1] == "" { actualEnv = actualEnv[:len(actualEnv)-1] } sort.Strings(actualEnv) goodEnv := []string{ "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", "HOME=/", } sort.Strings(goodEnv) if len(goodEnv) != len(actualEnv) { t.Fatalf("Wrong environment: should be %d variables, not: '%s'\n", len(goodEnv), strings.Join(actualEnv, ", ")) } for i := range goodEnv { if actualEnv[i] != goodEnv[i] { t.Fatalf("Wrong environment variable: should be %s, not %s", goodEnv[i], actualEnv[i]) } } } func grepFile(t *testing.T, path string, pattern string) { f, err := os.Open(path) if err != nil { t.Fatal(err) } defer f.Close() r := bufio.NewReader(f) var ( line string ) err = nil for err == nil { line, err = r.ReadString('\n') if strings.Contains(line, pattern) == true { return } } t.Fatalf("grepFile: pattern \"%s\" not found in \"%s\"", pattern, path) } func TestLXCConfig(t *testing.T) { runtime, err := newTestRuntime() if err != nil { t.Fatal(err) } defer nuke(runtime) // Memory is allocated randomly for testing rand.Seed(time.Now().UTC().UnixNano()) memMin := 33554432 memMax := 536870912 mem := memMin + rand.Intn(memMax-memMin) container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"/bin/true"}, Hostname: "foobar", Memory: int64(mem), }, ) if err != nil { t.Fatal(err) } defer runtime.Destroy(container) container.generateLXCConfig() grepFile(t, container.lxcConfigPath(), "lxc.utsname = foobar") grepFile(t, container.lxcConfigPath(), fmt.Sprintf("lxc.cgroup.memory.limit_in_bytes = %d", mem)) grepFile(t, container.lxcConfigPath(), fmt.Sprintf("lxc.cgroup.memory.memsw.limit_in_bytes = %d", mem*2)) } func BenchmarkRunSequencial(b *testing.B) { runtime, err := newTestRuntime() if err != nil { b.Fatal(err) } defer nuke(runtime) for i := 0; i < b.N; i++ { container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"echo", "-n", "foo"}, }, ) if err != nil { b.Fatal(err) } defer runtime.Destroy(container) output, err := container.Output() if err != nil { b.Fatal(err) } if string(output) != "foo" { b.Fatalf("Unexpected output: %s", output) } if err := runtime.Destroy(container); err != nil { b.Fatal(err) } } } func BenchmarkRunParallel(b *testing.B) { runtime, err := newTestRuntime() if err != nil { b.Fatal(err) } defer nuke(runtime) var tasks []chan error for i := 0; i < b.N; i++ { complete := make(chan error) tasks = append(tasks, complete) go func(i int, complete chan error) { container, err := runtime.Create(&Config{ Image: GetTestImage(runtime).Id, Cmd: []string{"echo", "-n", "foo"}, }, ) if err != nil { complete <- err return } defer runtime.Destroy(container) if err := container.Start(); err != nil { complete <- err return } if err := container.WaitTimeout(15 * time.Second); err != nil { complete <- err return } // if string(output) != "foo" { // complete <- fmt.Errorf("Unexecpted output: %v", string(output)) // } if err := runtime.Destroy(container); err != nil { complete <- err return } complete <- nil }(i, complete) } var errors []error for _, task := range tasks { err := <-task if err != nil { errors = append(errors, err) } } if len(errors) > 0 { b.Fatal(errors) } }