github.com/akerouanton/docker@v1.11.0-rc3/integration-cli/docker_cli_exec_test.go (about)

     1  // +build !test_no_exec
     2  
     3  package main
     4  
     5  import (
     6  	"bufio"
     7  	"fmt"
     8  	"net/http"
     9  	"os"
    10  	"os/exec"
    11  	"reflect"
    12  	"sort"
    13  	"strings"
    14  	"sync"
    15  	"time"
    16  
    17  	"github.com/docker/docker/pkg/integration/checker"
    18  	"github.com/go-check/check"
    19  )
    20  
    21  func (s *DockerSuite) TestExec(c *check.C) {
    22  	testRequires(c, DaemonIsLinux)
    23  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    24  	c.Assert(waitRun(strings.TrimSpace(out)), check.IsNil)
    25  
    26  	out, _ = dockerCmd(c, "exec", "testing", "cat", "/tmp/file")
    27  	out = strings.Trim(out, "\r\n")
    28  	c.Assert(out, checker.Equals, "test")
    29  
    30  }
    31  
    32  func (s *DockerSuite) TestExecInteractive(c *check.C) {
    33  	testRequires(c, DaemonIsLinux)
    34  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    35  
    36  	execCmd := exec.Command(dockerBinary, "exec", "-i", "testing", "sh")
    37  	stdin, err := execCmd.StdinPipe()
    38  	c.Assert(err, checker.IsNil)
    39  	stdout, err := execCmd.StdoutPipe()
    40  	c.Assert(err, checker.IsNil)
    41  
    42  	err = execCmd.Start()
    43  	c.Assert(err, checker.IsNil)
    44  	_, err = stdin.Write([]byte("cat /tmp/file\n"))
    45  	c.Assert(err, checker.IsNil)
    46  
    47  	r := bufio.NewReader(stdout)
    48  	line, err := r.ReadString('\n')
    49  	c.Assert(err, checker.IsNil)
    50  	line = strings.TrimSpace(line)
    51  	c.Assert(line, checker.Equals, "test")
    52  	err = stdin.Close()
    53  	c.Assert(err, checker.IsNil)
    54  	errChan := make(chan error)
    55  	go func() {
    56  		errChan <- execCmd.Wait()
    57  		close(errChan)
    58  	}()
    59  	select {
    60  	case err := <-errChan:
    61  		c.Assert(err, checker.IsNil)
    62  	case <-time.After(1 * time.Second):
    63  		c.Fatal("docker exec failed to exit on stdin close")
    64  	}
    65  
    66  }
    67  
    68  func (s *DockerSuite) TestExecAfterContainerRestart(c *check.C) {
    69  	testRequires(c, DaemonIsLinux)
    70  	out, _ := runSleepingContainer(c)
    71  	cleanedContainerID := strings.TrimSpace(out)
    72  	c.Assert(waitRun(cleanedContainerID), check.IsNil)
    73  	dockerCmd(c, "restart", cleanedContainerID)
    74  	c.Assert(waitRun(cleanedContainerID), check.IsNil)
    75  
    76  	out, _ = dockerCmd(c, "exec", cleanedContainerID, "echo", "hello")
    77  	outStr := strings.TrimSpace(out)
    78  	c.Assert(outStr, checker.Equals, "hello")
    79  }
    80  
    81  func (s *DockerDaemonSuite) TestExecAfterDaemonRestart(c *check.C) {
    82  	// TODO Windows CI: Requires a little work to get this ported.
    83  	testRequires(c, DaemonIsLinux)
    84  	testRequires(c, SameHostDaemon)
    85  
    86  	err := s.d.StartWithBusybox()
    87  	c.Assert(err, checker.IsNil)
    88  
    89  	out, err := s.d.Cmd("run", "-d", "--name", "top", "-p", "80", "busybox:latest", "top")
    90  	c.Assert(err, checker.IsNil, check.Commentf("Could not run top: %s", out))
    91  
    92  	err = s.d.Restart()
    93  	c.Assert(err, checker.IsNil, check.Commentf("Could not restart daemon"))
    94  
    95  	out, err = s.d.Cmd("start", "top")
    96  	c.Assert(err, checker.IsNil, check.Commentf("Could not start top after daemon restart: %s", out))
    97  
    98  	out, err = s.d.Cmd("exec", "top", "echo", "hello")
    99  	c.Assert(err, checker.IsNil, check.Commentf("Could not exec on container top: %s", out))
   100  
   101  	outStr := strings.TrimSpace(string(out))
   102  	c.Assert(outStr, checker.Equals, "hello")
   103  }
   104  
   105  // Regression test for #9155, #9044
   106  func (s *DockerSuite) TestExecEnv(c *check.C) {
   107  	// TODO Windows CI: This one is interesting and may just end up being a feature
   108  	// difference between Windows and Linux. On Windows, the environment is passed
   109  	// into the process that is launched, not into the machine environment. Hence
   110  	// a subsequent exec will not have LALA set/
   111  	testRequires(c, DaemonIsLinux)
   112  	runSleepingContainer(c, "-e", "LALA=value1", "-e", "LALA=value2", "-d", "--name", "testing")
   113  	c.Assert(waitRun("testing"), check.IsNil)
   114  
   115  	out, _ := dockerCmd(c, "exec", "testing", "env")
   116  	c.Assert(out, checker.Not(checker.Contains), "LALA=value1")
   117  	c.Assert(out, checker.Contains, "LALA=value2")
   118  	c.Assert(out, checker.Contains, "HOME=/root")
   119  }
   120  
   121  func (s *DockerSuite) TestExecExitStatus(c *check.C) {
   122  	runSleepingContainer(c, "-d", "--name", "top")
   123  
   124  	// Test normal (non-detached) case first
   125  	cmd := exec.Command(dockerBinary, "exec", "top", "sh", "-c", "exit 23")
   126  	ec, _ := runCommand(cmd)
   127  	c.Assert(ec, checker.Equals, 23)
   128  }
   129  
   130  func (s *DockerSuite) TestExecPausedContainer(c *check.C) {
   131  	// Windows does not support pause
   132  	testRequires(c, DaemonIsLinux)
   133  	defer unpauseAllContainers()
   134  
   135  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   136  	ContainerID := strings.TrimSpace(out)
   137  
   138  	dockerCmd(c, "pause", "testing")
   139  	out, _, err := dockerCmdWithError("exec", "-i", "-t", ContainerID, "echo", "hello")
   140  	c.Assert(err, checker.NotNil, check.Commentf("container should fail to exec new conmmand if it is paused"))
   141  
   142  	expected := ContainerID + " is paused, unpause the container before exec"
   143  	c.Assert(out, checker.Contains, expected, check.Commentf("container should not exec new command if it is paused"))
   144  }
   145  
   146  // regression test for #9476
   147  func (s *DockerSuite) TestExecTTYCloseStdin(c *check.C) {
   148  	// TODO Windows CI: This requires some work to port to Windows.
   149  	testRequires(c, DaemonIsLinux)
   150  	dockerCmd(c, "run", "-d", "-it", "--name", "exec_tty_stdin", "busybox")
   151  
   152  	cmd := exec.Command(dockerBinary, "exec", "-i", "exec_tty_stdin", "cat")
   153  	stdinRw, err := cmd.StdinPipe()
   154  	c.Assert(err, checker.IsNil)
   155  
   156  	stdinRw.Write([]byte("test"))
   157  	stdinRw.Close()
   158  
   159  	out, _, err := runCommandWithOutput(cmd)
   160  	c.Assert(err, checker.IsNil, check.Commentf(out))
   161  
   162  	out, _ = dockerCmd(c, "top", "exec_tty_stdin")
   163  	outArr := strings.Split(out, "\n")
   164  	c.Assert(len(outArr), checker.LessOrEqualThan, 3, check.Commentf("exec process left running"))
   165  	c.Assert(out, checker.Not(checker.Contains), "nsenter-exec")
   166  }
   167  
   168  func (s *DockerSuite) TestExecTTYWithoutStdin(c *check.C) {
   169  	// TODO Windows CI: This requires some work to port to Windows.
   170  	testRequires(c, DaemonIsLinux)
   171  	out, _ := dockerCmd(c, "run", "-d", "-ti", "busybox")
   172  	id := strings.TrimSpace(out)
   173  	c.Assert(waitRun(id), checker.IsNil)
   174  
   175  	errChan := make(chan error)
   176  	go func() {
   177  		defer close(errChan)
   178  
   179  		cmd := exec.Command(dockerBinary, "exec", "-ti", id, "true")
   180  		if _, err := cmd.StdinPipe(); err != nil {
   181  			errChan <- err
   182  			return
   183  		}
   184  
   185  		expected := "cannot enable tty mode"
   186  		if out, _, err := runCommandWithOutput(cmd); err == nil {
   187  			errChan <- fmt.Errorf("exec should have failed")
   188  			return
   189  		} else if !strings.Contains(out, expected) {
   190  			errChan <- fmt.Errorf("exec failed with error %q: expected %q", out, expected)
   191  			return
   192  		}
   193  	}()
   194  
   195  	select {
   196  	case err := <-errChan:
   197  		c.Assert(err, check.IsNil)
   198  	case <-time.After(3 * time.Second):
   199  		c.Fatal("exec is running but should have failed")
   200  	}
   201  }
   202  
   203  func (s *DockerSuite) TestExecParseError(c *check.C) {
   204  	// TODO Windows CI: Requires some extra work. Consider copying the
   205  	// runSleepingContainer helper to have an exec version.
   206  	testRequires(c, DaemonIsLinux)
   207  	dockerCmd(c, "run", "-d", "--name", "top", "busybox", "top")
   208  
   209  	// Test normal (non-detached) case first
   210  	cmd := exec.Command(dockerBinary, "exec", "top")
   211  	_, stderr, _, err := runCommandWithStdoutStderr(cmd)
   212  	c.Assert(err, checker.NotNil)
   213  	c.Assert(stderr, checker.Contains, "See '"+dockerBinary+" exec --help'")
   214  }
   215  
   216  func (s *DockerSuite) TestExecStopNotHanging(c *check.C) {
   217  	// TODO Windows CI: Requires some extra work. Consider copying the
   218  	// runSleepingContainer helper to have an exec version.
   219  	testRequires(c, DaemonIsLinux)
   220  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   221  
   222  	err := exec.Command(dockerBinary, "exec", "testing", "top").Start()
   223  	c.Assert(err, checker.IsNil)
   224  
   225  	type dstop struct {
   226  		out []byte
   227  		err error
   228  	}
   229  
   230  	ch := make(chan dstop)
   231  	go func() {
   232  		out, err := exec.Command(dockerBinary, "stop", "testing").CombinedOutput()
   233  		ch <- dstop{out, err}
   234  		close(ch)
   235  	}()
   236  	select {
   237  	case <-time.After(3 * time.Second):
   238  		c.Fatal("Container stop timed out")
   239  	case s := <-ch:
   240  		c.Assert(s.err, check.IsNil)
   241  	}
   242  }
   243  
   244  func (s *DockerSuite) TestExecCgroup(c *check.C) {
   245  	// Not applicable on Windows - using Linux specific functionality
   246  	testRequires(c, NotUserNamespace)
   247  	testRequires(c, DaemonIsLinux)
   248  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   249  
   250  	out, _ := dockerCmd(c, "exec", "testing", "cat", "/proc/1/cgroup")
   251  	containerCgroups := sort.StringSlice(strings.Split(out, "\n"))
   252  
   253  	var wg sync.WaitGroup
   254  	var mu sync.Mutex
   255  	execCgroups := []sort.StringSlice{}
   256  	errChan := make(chan error)
   257  	// exec a few times concurrently to get consistent failure
   258  	for i := 0; i < 5; i++ {
   259  		wg.Add(1)
   260  		go func() {
   261  			out, _, err := dockerCmdWithError("exec", "testing", "cat", "/proc/self/cgroup")
   262  			if err != nil {
   263  				errChan <- err
   264  				return
   265  			}
   266  			cg := sort.StringSlice(strings.Split(out, "\n"))
   267  
   268  			mu.Lock()
   269  			execCgroups = append(execCgroups, cg)
   270  			mu.Unlock()
   271  			wg.Done()
   272  		}()
   273  	}
   274  	wg.Wait()
   275  	close(errChan)
   276  
   277  	for err := range errChan {
   278  		c.Assert(err, checker.IsNil)
   279  	}
   280  
   281  	for _, cg := range execCgroups {
   282  		if !reflect.DeepEqual(cg, containerCgroups) {
   283  			fmt.Println("exec cgroups:")
   284  			for _, name := range cg {
   285  				fmt.Printf(" %s\n", name)
   286  			}
   287  
   288  			fmt.Println("container cgroups:")
   289  			for _, name := range containerCgroups {
   290  				fmt.Printf(" %s\n", name)
   291  			}
   292  			c.Fatal("cgroups mismatched")
   293  		}
   294  	}
   295  }
   296  
   297  func (s *DockerSuite) TestExecInspectID(c *check.C) {
   298  	out, _ := runSleepingContainer(c, "-d")
   299  	id := strings.TrimSuffix(out, "\n")
   300  
   301  	out = inspectField(c, id, "ExecIDs")
   302  	c.Assert(out, checker.Equals, "[]", check.Commentf("ExecIDs should be empty, got: %s", out))
   303  
   304  	// Start an exec, have it block waiting so we can do some checking
   305  	cmd := exec.Command(dockerBinary, "exec", id, "sh", "-c",
   306  		"while ! test -e /execid1; do sleep 1; done")
   307  
   308  	err := cmd.Start()
   309  	c.Assert(err, checker.IsNil, check.Commentf("failed to start the exec cmd"))
   310  
   311  	// Give the exec 10 chances/seconds to start then give up and stop the test
   312  	tries := 10
   313  	for i := 0; i < tries; i++ {
   314  		// Since its still running we should see exec as part of the container
   315  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   316  
   317  		if out != "[]" && out != "<no value>" {
   318  			break
   319  		}
   320  		c.Assert(i+1, checker.Not(checker.Equals), tries, check.Commentf("ExecIDs still empty after 10 second"))
   321  		time.Sleep(1 * time.Second)
   322  	}
   323  
   324  	// Save execID for later
   325  	execID, err := inspectFilter(id, "index .ExecIDs 0")
   326  	c.Assert(err, checker.IsNil, check.Commentf("failed to get the exec id"))
   327  
   328  	// End the exec by creating the missing file
   329  	err = exec.Command(dockerBinary, "exec", id,
   330  		"sh", "-c", "touch /execid1").Run()
   331  
   332  	c.Assert(err, checker.IsNil, check.Commentf("failed to run the 2nd exec cmd"))
   333  
   334  	// Wait for 1st exec to complete
   335  	cmd.Wait()
   336  
   337  	// Give the exec 10 chances/seconds to stop then give up and stop the test
   338  	for i := 0; i < tries; i++ {
   339  		// Since its still running we should see exec as part of the container
   340  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   341  
   342  		if out == "[]" {
   343  			break
   344  		}
   345  		c.Assert(i+1, checker.Not(checker.Equals), tries, check.Commentf("ExecIDs still not empty after 10 second"))
   346  		time.Sleep(1 * time.Second)
   347  	}
   348  
   349  	// But we should still be able to query the execID
   350  	sc, body, err := sockRequest("GET", "/exec/"+execID+"/json", nil)
   351  	c.Assert(sc, checker.Equals, http.StatusOK, check.Commentf("received status != 200 OK: %d\n%s", sc, body))
   352  
   353  	// Now delete the container and then an 'inspect' on the exec should
   354  	// result in a 404 (not 'container not running')
   355  	out, ec := dockerCmd(c, "rm", "-f", id)
   356  	c.Assert(ec, checker.Equals, 0, check.Commentf("error removing container: %s", out))
   357  	sc, body, err = sockRequest("GET", "/exec/"+execID+"/json", nil)
   358  	c.Assert(sc, checker.Equals, http.StatusNotFound, check.Commentf("received status != 404: %d\n%s", sc, body))
   359  }
   360  
   361  func (s *DockerSuite) TestLinksPingLinkedContainersOnRename(c *check.C) {
   362  	// Problematic on Windows as Windows does not support links
   363  	testRequires(c, DaemonIsLinux)
   364  	var out string
   365  	out, _ = dockerCmd(c, "run", "-d", "--name", "container1", "busybox", "top")
   366  	idA := strings.TrimSpace(out)
   367  	c.Assert(idA, checker.Not(checker.Equals), "", check.Commentf("%s, id should not be nil", out))
   368  	out, _ = dockerCmd(c, "run", "-d", "--link", "container1:alias1", "--name", "container2", "busybox", "top")
   369  	idB := strings.TrimSpace(out)
   370  	c.Assert(idB, checker.Not(checker.Equals), "", check.Commentf("%s, id should not be nil", out))
   371  
   372  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   373  	dockerCmd(c, "rename", "container1", "container_new")
   374  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   375  }
   376  
   377  func (s *DockerSuite) TestRunMutableNetworkFiles(c *check.C) {
   378  	// Not applicable on Windows to Windows CI.
   379  	testRequires(c, SameHostDaemon, DaemonIsLinux)
   380  	for _, fn := range []string{"resolv.conf", "hosts"} {
   381  		deleteAllContainers()
   382  
   383  		content, err := runCommandAndReadContainerFile(fn, exec.Command(dockerBinary, "run", "-d", "--name", "c1", "busybox", "sh", "-c", fmt.Sprintf("echo success >/etc/%s && top", fn)))
   384  		c.Assert(err, checker.IsNil)
   385  
   386  		c.Assert(strings.TrimSpace(string(content)), checker.Equals, "success", check.Commentf("Content was not what was modified in the container", string(content)))
   387  
   388  		out, _ := dockerCmd(c, "run", "-d", "--name", "c2", "busybox", "top")
   389  		contID := strings.TrimSpace(out)
   390  		netFilePath := containerStorageFile(contID, fn)
   391  
   392  		f, err := os.OpenFile(netFilePath, os.O_WRONLY|os.O_SYNC|os.O_APPEND, 0644)
   393  		c.Assert(err, checker.IsNil)
   394  
   395  		if _, err := f.Seek(0, 0); err != nil {
   396  			f.Close()
   397  			c.Fatal(err)
   398  		}
   399  
   400  		if err := f.Truncate(0); err != nil {
   401  			f.Close()
   402  			c.Fatal(err)
   403  		}
   404  
   405  		if _, err := f.Write([]byte("success2\n")); err != nil {
   406  			f.Close()
   407  			c.Fatal(err)
   408  		}
   409  		f.Close()
   410  
   411  		res, _ := dockerCmd(c, "exec", contID, "cat", "/etc/"+fn)
   412  		c.Assert(res, checker.Equals, "success2\n")
   413  	}
   414  }
   415  
   416  func (s *DockerSuite) TestExecWithUser(c *check.C) {
   417  	// TODO Windows CI: This may be fixable in the future once Windows
   418  	// supports users
   419  	testRequires(c, DaemonIsLinux)
   420  	dockerCmd(c, "run", "-d", "--name", "parent", "busybox", "top")
   421  
   422  	out, _ := dockerCmd(c, "exec", "-u", "1", "parent", "id")
   423  	c.Assert(out, checker.Contains, "uid=1(daemon) gid=1(daemon)")
   424  
   425  	out, _ = dockerCmd(c, "exec", "-u", "root", "parent", "id")
   426  	c.Assert(out, checker.Contains, "uid=0(root) gid=0(root)", check.Commentf("exec with user by id expected daemon user got %s", out))
   427  }
   428  
   429  func (s *DockerSuite) TestExecWithPrivileged(c *check.C) {
   430  	// Not applicable on Windows
   431  	testRequires(c, DaemonIsLinux, NotUserNamespace)
   432  	// Start main loop which attempts mknod repeatedly
   433  	dockerCmd(c, "run", "-d", "--name", "parent", "--cap-drop=ALL", "busybox", "sh", "-c", `while (true); do if [ -e /exec_priv ]; then cat /exec_priv && mknod /tmp/sda b 8 0 && echo "Success"; else echo "Privileged exec has not run yet"; fi; usleep 10000; done`)
   434  
   435  	// Check exec mknod doesn't work
   436  	cmd := exec.Command(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdb b 8 16")
   437  	out, _, err := runCommandWithOutput(cmd)
   438  	c.Assert(err, checker.NotNil, check.Commentf("exec mknod in --cap-drop=ALL container without --privileged should fail"))
   439  	c.Assert(out, checker.Contains, "Operation not permitted", check.Commentf("exec mknod in --cap-drop=ALL container without --privileged should fail"))
   440  
   441  	// Check exec mknod does work with --privileged
   442  	cmd = exec.Command(dockerBinary, "exec", "--privileged", "parent", "sh", "-c", `echo "Running exec --privileged" > /exec_priv && mknod /tmp/sdb b 8 16 && usleep 50000 && echo "Finished exec --privileged" > /exec_priv && echo ok`)
   443  	out, _, err = runCommandWithOutput(cmd)
   444  	c.Assert(err, checker.IsNil)
   445  
   446  	actual := strings.TrimSpace(out)
   447  	c.Assert(actual, checker.Equals, "ok", check.Commentf("exec mknod in --cap-drop=ALL container with --privileged failed, output: %q", out))
   448  
   449  	// Check subsequent unprivileged exec cannot mknod
   450  	cmd = exec.Command(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdc b 8 32")
   451  	out, _, err = runCommandWithOutput(cmd)
   452  	c.Assert(err, checker.NotNil, check.Commentf("repeating exec mknod in --cap-drop=ALL container after --privileged without --privileged should fail"))
   453  	c.Assert(out, checker.Contains, "Operation not permitted", check.Commentf("repeating exec mknod in --cap-drop=ALL container after --privileged without --privileged should fail"))
   454  
   455  	// Confirm at no point was mknod allowed
   456  	logCmd := exec.Command(dockerBinary, "logs", "parent")
   457  	out, _, err = runCommandWithOutput(logCmd)
   458  	c.Assert(err, checker.IsNil)
   459  	c.Assert(out, checker.Not(checker.Contains), "Success")
   460  
   461  }
   462  
   463  func (s *DockerSuite) TestExecWithImageUser(c *check.C) {
   464  	// Not applicable on Windows
   465  	testRequires(c, DaemonIsLinux)
   466  	name := "testbuilduser"
   467  	_, err := buildImage(name,
   468  		`FROM busybox
   469  		RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd
   470  		USER dockerio`,
   471  		true)
   472  	c.Assert(err, checker.IsNil)
   473  
   474  	dockerCmd(c, "run", "-d", "--name", "dockerioexec", name, "top")
   475  
   476  	out, _ := dockerCmd(c, "exec", "dockerioexec", "whoami")
   477  	c.Assert(out, checker.Contains, "dockerio", check.Commentf("exec with user by id expected dockerio user got %s", out))
   478  }
   479  
   480  func (s *DockerSuite) TestExecOnReadonlyContainer(c *check.C) {
   481  	// Windows does not support read-only
   482  	// --read-only + userns has remount issues
   483  	testRequires(c, DaemonIsLinux, NotUserNamespace)
   484  	dockerCmd(c, "run", "-d", "--read-only", "--name", "parent", "busybox", "top")
   485  	dockerCmd(c, "exec", "parent", "true")
   486  }
   487  
   488  func (s *DockerSuite) TestExecUlimits(c *check.C) {
   489  	testRequires(c, DaemonIsLinux)
   490  	name := "testexeculimits"
   491  	runSleepingContainer(c, "-d", "--ulimit", "nproc=21", "--name", name)
   492  	c.Assert(waitRun(name), checker.IsNil)
   493  
   494  	out, _, err := dockerCmdWithError("exec", name, "sh", "-c", "ulimit -p")
   495  	c.Assert(err, checker.IsNil)
   496  	c.Assert(strings.TrimSpace(out), checker.Equals, "21")
   497  }
   498  
   499  // #15750
   500  func (s *DockerSuite) TestExecStartFails(c *check.C) {
   501  	// TODO Windows CI. This test should be portable. Figure out why it fails
   502  	// currently.
   503  	testRequires(c, DaemonIsLinux)
   504  	name := "exec-15750"
   505  	runSleepingContainer(c, "-d", "--name", name)
   506  	c.Assert(waitRun(name), checker.IsNil)
   507  
   508  	out, _, err := dockerCmdWithError("exec", name, "no-such-cmd")
   509  	c.Assert(err, checker.NotNil, check.Commentf(out))
   510  	c.Assert(out, checker.Contains, "executable file not found")
   511  }