github.com/rumpl/bof@v23.0.0-rc.2+incompatible/integration-cli/docker_cli_exec_test.go (about)

     1  package main
     2  
     3  import (
     4  	"bufio"
     5  	"context"
     6  	"fmt"
     7  	"os"
     8  	"os/exec"
     9  	"reflect"
    10  	"runtime"
    11  	"sort"
    12  	"strings"
    13  	"sync"
    14  	"testing"
    15  	"time"
    16  
    17  	"github.com/docker/docker/client"
    18  	"github.com/docker/docker/integration-cli/cli"
    19  	"github.com/docker/docker/integration-cli/cli/build"
    20  	"gotest.tools/v3/assert"
    21  	is "gotest.tools/v3/assert/cmp"
    22  	"gotest.tools/v3/icmd"
    23  )
    24  
    25  type DockerCLIExecSuite struct {
    26  	ds *DockerSuite
    27  }
    28  
    29  func (s *DockerCLIExecSuite) TearDownTest(c *testing.T) {
    30  	s.ds.TearDownTest(c)
    31  }
    32  
    33  func (s *DockerCLIExecSuite) OnTimeout(c *testing.T) {
    34  	s.ds.OnTimeout(c)
    35  }
    36  
    37  func (s *DockerCLIExecSuite) TestExec(c *testing.T) {
    38  	testRequires(c, DaemonIsLinux)
    39  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    40  	assert.NilError(c, waitRun(strings.TrimSpace(out)))
    41  
    42  	out, _ = dockerCmd(c, "exec", "testing", "cat", "/tmp/file")
    43  	assert.Equal(c, strings.Trim(out, "\r\n"), "test")
    44  }
    45  
    46  func (s *DockerCLIExecSuite) TestExecInteractive(c *testing.T) {
    47  	testRequires(c, DaemonIsLinux)
    48  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    49  
    50  	execCmd := exec.Command(dockerBinary, "exec", "-i", "testing", "sh")
    51  	stdin, err := execCmd.StdinPipe()
    52  	assert.NilError(c, err)
    53  	stdout, err := execCmd.StdoutPipe()
    54  	assert.NilError(c, err)
    55  
    56  	err = execCmd.Start()
    57  	assert.NilError(c, err)
    58  	_, err = stdin.Write([]byte("cat /tmp/file\n"))
    59  	assert.NilError(c, err)
    60  
    61  	r := bufio.NewReader(stdout)
    62  	line, err := r.ReadString('\n')
    63  	assert.NilError(c, err)
    64  	line = strings.TrimSpace(line)
    65  	assert.Equal(c, line, "test")
    66  	err = stdin.Close()
    67  	assert.NilError(c, err)
    68  	errChan := make(chan error, 1)
    69  	go func() {
    70  		errChan <- execCmd.Wait()
    71  		close(errChan)
    72  	}()
    73  	select {
    74  	case err := <-errChan:
    75  		assert.NilError(c, err)
    76  	case <-time.After(1 * time.Second):
    77  		c.Fatal("docker exec failed to exit on stdin close")
    78  	}
    79  }
    80  
    81  func (s *DockerCLIExecSuite) TestExecAfterContainerRestart(c *testing.T) {
    82  	out := runSleepingContainer(c)
    83  	cleanedContainerID := strings.TrimSpace(out)
    84  	assert.NilError(c, waitRun(cleanedContainerID))
    85  	dockerCmd(c, "restart", cleanedContainerID)
    86  	assert.NilError(c, waitRun(cleanedContainerID))
    87  
    88  	out, _ = dockerCmd(c, "exec", cleanedContainerID, "echo", "hello")
    89  	assert.Equal(c, strings.TrimSpace(out), "hello")
    90  }
    91  
    92  func (s *DockerDaemonSuite) TestExecAfterDaemonRestart(c *testing.T) {
    93  	// TODO Windows CI: DockerDaemonSuite doesn't run on Windows, and requires a little work to get this ported.
    94  	s.d.StartWithBusybox(c)
    95  
    96  	out, err := s.d.Cmd("run", "-d", "--name", "top", "-p", "80", "busybox:latest", "top")
    97  	assert.NilError(c, err, "Could not run top: %s", out)
    98  
    99  	s.d.Restart(c)
   100  
   101  	out, err = s.d.Cmd("start", "top")
   102  	assert.NilError(c, err, "Could not start top after daemon restart: %s", out)
   103  
   104  	out, err = s.d.Cmd("exec", "top", "echo", "hello")
   105  	assert.NilError(c, err, "Could not exec on container top: %s", out)
   106  	assert.Equal(c, strings.TrimSpace(out), "hello")
   107  }
   108  
   109  // Regression test for #9155, #9044
   110  func (s *DockerCLIExecSuite) TestExecEnv(c *testing.T) {
   111  	// TODO Windows CI: This one is interesting and may just end up being a feature
   112  	// difference between Windows and Linux. On Windows, the environment is passed
   113  	// into the process that is launched, not into the machine environment. Hence
   114  	// a subsequent exec will not have LALA set/
   115  	testRequires(c, DaemonIsLinux)
   116  	runSleepingContainer(c, "-e", "LALA=value1", "-e", "LALA=value2", "-d", "--name", "testing")
   117  	assert.NilError(c, waitRun("testing"))
   118  
   119  	out, _ := dockerCmd(c, "exec", "testing", "env")
   120  	assert.Check(c, !strings.Contains(out, "LALA=value1"))
   121  	assert.Check(c, strings.Contains(out, "LALA=value2"))
   122  	assert.Check(c, strings.Contains(out, "HOME=/root"))
   123  }
   124  
   125  func (s *DockerCLIExecSuite) TestExecSetEnv(c *testing.T) {
   126  	testRequires(c, DaemonIsLinux)
   127  	runSleepingContainer(c, "-e", "HOME=/root", "-d", "--name", "testing")
   128  	assert.NilError(c, waitRun("testing"))
   129  
   130  	out, _ := dockerCmd(c, "exec", "-e", "HOME=/another", "-e", "ABC=xyz", "testing", "env")
   131  	assert.Check(c, !strings.Contains(out, "HOME=/root"))
   132  	assert.Check(c, strings.Contains(out, "HOME=/another"))
   133  	assert.Check(c, strings.Contains(out, "ABC=xyz"))
   134  }
   135  
   136  func (s *DockerCLIExecSuite) TestExecExitStatus(c *testing.T) {
   137  	runSleepingContainer(c, "-d", "--name", "top")
   138  
   139  	result := icmd.RunCommand(dockerBinary, "exec", "top", "sh", "-c", "exit 23")
   140  	result.Assert(c, icmd.Expected{ExitCode: 23, Error: "exit status 23"})
   141  }
   142  
   143  func (s *DockerCLIExecSuite) TestExecPausedContainer(c *testing.T) {
   144  	testRequires(c, IsPausable)
   145  
   146  	out := runSleepingContainer(c, "-d", "--name", "testing")
   147  	ContainerID := strings.TrimSpace(out)
   148  
   149  	dockerCmd(c, "pause", "testing")
   150  	out, _, err := dockerCmdWithError("exec", ContainerID, "echo", "hello")
   151  	assert.ErrorContains(c, err, "", "container should fail to exec new command if it is paused")
   152  
   153  	expected := ContainerID + " is paused, unpause the container before exec"
   154  	assert.Assert(c, is.Contains(out, expected), "container should not exec new command if it is paused")
   155  }
   156  
   157  // regression test for #9476
   158  func (s *DockerCLIExecSuite) TestExecTTYCloseStdin(c *testing.T) {
   159  	// TODO Windows CI: This requires some work to port to Windows.
   160  	testRequires(c, DaemonIsLinux)
   161  	dockerCmd(c, "run", "-d", "-it", "--name", "exec_tty_stdin", "busybox")
   162  
   163  	cmd := exec.Command(dockerBinary, "exec", "-i", "exec_tty_stdin", "cat")
   164  	stdinRw, err := cmd.StdinPipe()
   165  	assert.NilError(c, err)
   166  
   167  	stdinRw.Write([]byte("test"))
   168  	stdinRw.Close()
   169  
   170  	out, _, err := runCommandWithOutput(cmd)
   171  	assert.NilError(c, err, out)
   172  
   173  	out, _ = dockerCmd(c, "top", "exec_tty_stdin")
   174  	outArr := strings.Split(out, "\n")
   175  	assert.Assert(c, len(outArr) <= 3, "exec process left running")
   176  	assert.Assert(c, !strings.Contains(out, "nsenter-exec"))
   177  }
   178  
   179  func (s *DockerCLIExecSuite) TestExecTTYWithoutStdin(c *testing.T) {
   180  	out, _ := dockerCmd(c, "run", "-d", "-ti", "busybox")
   181  	id := strings.TrimSpace(out)
   182  	assert.NilError(c, waitRun(id))
   183  
   184  	errChan := make(chan error, 1)
   185  	go func() {
   186  		defer close(errChan)
   187  
   188  		cmd := exec.Command(dockerBinary, "exec", "-ti", id, "true")
   189  		if _, err := cmd.StdinPipe(); err != nil {
   190  			errChan <- err
   191  			return
   192  		}
   193  
   194  		expected := "the input device is not a TTY"
   195  		if runtime.GOOS == "windows" {
   196  			expected += ".  If you are using mintty, try prefixing the command with 'winpty'"
   197  		}
   198  		if out, _, err := runCommandWithOutput(cmd); err == nil {
   199  			errChan <- fmt.Errorf("exec should have failed")
   200  			return
   201  		} else if !strings.Contains(out, expected) {
   202  			errChan <- fmt.Errorf("exec failed with error %q: expected %q", out, expected)
   203  			return
   204  		}
   205  	}()
   206  
   207  	select {
   208  	case err := <-errChan:
   209  		assert.NilError(c, err)
   210  	case <-time.After(3 * time.Second):
   211  		c.Fatal("exec is running but should have failed")
   212  	}
   213  }
   214  
   215  // FIXME(vdemeester) this should be a unit tests on cli/command/container package
   216  func (s *DockerCLIExecSuite) TestExecParseError(c *testing.T) {
   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", "top", "busybox", "top")
   221  
   222  	// Test normal (non-detached) case first
   223  	icmd.RunCommand(dockerBinary, "exec", "top").Assert(c, icmd.Expected{
   224  		ExitCode: 1,
   225  		Error:    "exit status 1",
   226  		Err:      "See 'docker exec --help'",
   227  	})
   228  }
   229  
   230  func (s *DockerCLIExecSuite) TestExecStopNotHanging(c *testing.T) {
   231  	// TODO Windows CI: Requires some extra work. Consider copying the
   232  	// runSleepingContainer helper to have an exec version.
   233  	testRequires(c, DaemonIsLinux)
   234  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   235  
   236  	result := icmd.StartCmd(icmd.Command(dockerBinary, "exec", "testing", "top"))
   237  	result.Assert(c, icmd.Success)
   238  	go icmd.WaitOnCmd(0, result)
   239  
   240  	type dstop struct {
   241  		out string
   242  		err error
   243  	}
   244  	ch := make(chan dstop, 1)
   245  	go func() {
   246  		result := icmd.RunCommand(dockerBinary, "stop", "testing")
   247  		ch <- dstop{result.Combined(), result.Error}
   248  		close(ch)
   249  	}()
   250  	select {
   251  	case <-time.After(3 * time.Second):
   252  		c.Fatal("Container stop timed out")
   253  	case s := <-ch:
   254  		assert.NilError(c, s.err)
   255  	}
   256  }
   257  
   258  func (s *DockerCLIExecSuite) TestExecCgroup(c *testing.T) {
   259  	// Not applicable on Windows - using Linux specific functionality
   260  	testRequires(c, NotUserNamespace)
   261  	testRequires(c, DaemonIsLinux)
   262  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   263  
   264  	out, _ := dockerCmd(c, "exec", "testing", "cat", "/proc/1/cgroup")
   265  	containerCgroups := sort.StringSlice(strings.Split(out, "\n"))
   266  
   267  	var wg sync.WaitGroup
   268  	var mu sync.Mutex
   269  	var execCgroups []sort.StringSlice
   270  	errChan := make(chan error, 5)
   271  	// exec a few times concurrently to get consistent failure
   272  	for i := 0; i < 5; i++ {
   273  		wg.Add(1)
   274  		go func() {
   275  			defer wg.Done()
   276  			out, _, err := dockerCmdWithError("exec", "testing", "cat", "/proc/self/cgroup")
   277  			if err != nil {
   278  				errChan <- err
   279  				return
   280  			}
   281  			cg := sort.StringSlice(strings.Split(out, "\n"))
   282  
   283  			mu.Lock()
   284  			execCgroups = append(execCgroups, cg)
   285  			mu.Unlock()
   286  		}()
   287  	}
   288  	wg.Wait()
   289  	close(errChan)
   290  
   291  	for err := range errChan {
   292  		assert.NilError(c, err)
   293  	}
   294  
   295  	for _, cg := range execCgroups {
   296  		if !reflect.DeepEqual(cg, containerCgroups) {
   297  			fmt.Println("exec cgroups:")
   298  			for _, name := range cg {
   299  				fmt.Printf(" %s\n", name)
   300  			}
   301  
   302  			fmt.Println("container cgroups:")
   303  			for _, name := range containerCgroups {
   304  				fmt.Printf(" %s\n", name)
   305  			}
   306  			c.Fatal("cgroups mismatched")
   307  		}
   308  	}
   309  }
   310  
   311  func (s *DockerCLIExecSuite) TestExecInspectID(c *testing.T) {
   312  	out := runSleepingContainer(c, "-d")
   313  	id := strings.TrimSuffix(out, "\n")
   314  
   315  	out = inspectField(c, id, "ExecIDs")
   316  	assert.Equal(c, out, "[]", "ExecIDs should be empty, got: %s", out)
   317  
   318  	// Start an exec, have it block waiting so we can do some checking
   319  	cmd := exec.Command(dockerBinary, "exec", id, "sh", "-c",
   320  		"while ! test -e /execid1; do sleep 1; done")
   321  
   322  	err := cmd.Start()
   323  	assert.NilError(c, err, "failed to start the exec cmd")
   324  
   325  	// Give the exec 10 chances/seconds to start then give up and stop the test
   326  	tries := 10
   327  	for i := 0; i < tries; i++ {
   328  		// Since its still running we should see exec as part of the container
   329  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   330  
   331  		if out != "[]" && out != "<no value>" {
   332  			break
   333  		}
   334  		assert.Check(c, i+1 != tries, "ExecIDs still empty after 10 second")
   335  		time.Sleep(1 * time.Second)
   336  	}
   337  
   338  	// Save execID for later
   339  	execID, err := inspectFilter(id, "index .ExecIDs 0")
   340  	assert.NilError(c, err, "failed to get the exec id")
   341  
   342  	// End the exec by creating the missing file
   343  	err = exec.Command(dockerBinary, "exec", id, "sh", "-c", "touch /execid1").Run()
   344  	assert.NilError(c, err, "failed to run the 2nd exec cmd")
   345  
   346  	// Wait for 1st exec to complete
   347  	cmd.Wait()
   348  
   349  	// Give the exec 10 chances/seconds to stop then give up and stop the test
   350  	for i := 0; i < tries; i++ {
   351  		// Since its still running we should see exec as part of the container
   352  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   353  
   354  		if out == "[]" {
   355  			break
   356  		}
   357  		assert.Check(c, i+1 != tries, "ExecIDs still empty after 10 second")
   358  		time.Sleep(1 * time.Second)
   359  	}
   360  
   361  	// But we should still be able to query the execID
   362  	cli, err := client.NewClientWithOpts(client.FromEnv)
   363  	assert.NilError(c, err)
   364  	defer cli.Close()
   365  
   366  	_, err = cli.ContainerExecInspect(context.Background(), execID)
   367  	assert.NilError(c, err)
   368  
   369  	// Now delete the container and then an 'inspect' on the exec should
   370  	// result in a 404 (not 'container not running')
   371  	out, ec := dockerCmd(c, "rm", "-f", id)
   372  	assert.Equal(c, ec, 0, "error removing container: %s", out)
   373  
   374  	_, err = cli.ContainerExecInspect(context.Background(), execID)
   375  	assert.ErrorContains(c, err, "No such exec instance")
   376  }
   377  
   378  func (s *DockerCLIExecSuite) TestLinksPingLinkedContainersOnRename(c *testing.T) {
   379  	// Problematic on Windows as Windows does not support links
   380  	testRequires(c, DaemonIsLinux)
   381  	var out string
   382  	out, _ = dockerCmd(c, "run", "-d", "--name", "container1", "busybox", "top")
   383  	idA := strings.TrimSpace(out)
   384  	assert.Assert(c, idA != "", "%s, id should not be nil", out)
   385  	out, _ = dockerCmd(c, "run", "-d", "--link", "container1:alias1", "--name", "container2", "busybox", "top")
   386  	idB := strings.TrimSpace(out)
   387  	assert.Assert(c, idB != "", "%s, id should not be nil", out)
   388  
   389  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   390  	dockerCmd(c, "rename", "container1", "container_new")
   391  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   392  }
   393  
   394  func (s *DockerCLIExecSuite) TestRunMutableNetworkFiles(c *testing.T) {
   395  	// Not applicable on Windows to Windows CI.
   396  	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)
   397  	for _, fn := range []string{"resolv.conf", "hosts"} {
   398  		containers := cli.DockerCmd(c, "ps", "-q", "-a").Combined()
   399  		if containers != "" {
   400  			cli.DockerCmd(c, append([]string{"rm", "-fv"}, strings.Split(strings.TrimSpace(containers), "\n")...)...)
   401  		}
   402  
   403  		content := runCommandAndReadContainerFile(c, fn, dockerBinary, "run", "-d", "--name", "c1", "busybox", "sh", "-c", fmt.Sprintf("echo success >/etc/%s && top", fn))
   404  
   405  		assert.Equal(c, strings.TrimSpace(string(content)), "success", "Content was not what was modified in the container", string(content))
   406  
   407  		out, _ := dockerCmd(c, "run", "-d", "--name", "c2", "busybox", "top")
   408  		contID := strings.TrimSpace(out)
   409  		netFilePath := containerStorageFile(contID, fn)
   410  
   411  		f, err := os.OpenFile(netFilePath, os.O_WRONLY|os.O_SYNC|os.O_APPEND, 0644)
   412  		assert.NilError(c, err)
   413  
   414  		if _, err := f.Seek(0, 0); err != nil {
   415  			f.Close()
   416  			c.Fatal(err)
   417  		}
   418  
   419  		if err := f.Truncate(0); err != nil {
   420  			f.Close()
   421  			c.Fatal(err)
   422  		}
   423  
   424  		if _, err := f.Write([]byte("success2\n")); err != nil {
   425  			f.Close()
   426  			c.Fatal(err)
   427  		}
   428  		f.Close()
   429  
   430  		res, _ := dockerCmd(c, "exec", contID, "cat", "/etc/"+fn)
   431  		assert.Equal(c, res, "success2\n")
   432  	}
   433  }
   434  
   435  func (s *DockerCLIExecSuite) TestExecWithUser(c *testing.T) {
   436  	// TODO Windows CI: This may be fixable in the future once Windows
   437  	// supports users
   438  	testRequires(c, DaemonIsLinux)
   439  	dockerCmd(c, "run", "-d", "--name", "parent", "busybox", "top")
   440  
   441  	out, _ := dockerCmd(c, "exec", "-u", "1", "parent", "id")
   442  	assert.Assert(c, strings.Contains(out, "uid=1(daemon) gid=1(daemon)"))
   443  
   444  	out, _ = dockerCmd(c, "exec", "-u", "root", "parent", "id")
   445  	assert.Assert(c, strings.Contains(out, "uid=0(root) gid=0(root)"), "exec with user by id expected daemon user got %s", out)
   446  }
   447  
   448  func (s *DockerCLIExecSuite) TestExecWithPrivileged(c *testing.T) {
   449  	// Not applicable on Windows
   450  	testRequires(c, DaemonIsLinux, NotUserNamespace)
   451  	// Start main loop which attempts mknod repeatedly
   452  	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`)
   453  
   454  	// Check exec mknod doesn't work
   455  	icmd.RunCommand(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdb b 8 16").Assert(c, icmd.Expected{
   456  		ExitCode: 1,
   457  		Err:      "Operation not permitted",
   458  	})
   459  
   460  	// Check exec mknod does work with --privileged
   461  	result := icmd.RunCommand(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`)
   462  	result.Assert(c, icmd.Success)
   463  
   464  	actual := strings.TrimSpace(result.Combined())
   465  	assert.Equal(c, actual, "ok", "exec mknod in --cap-drop=ALL container with --privileged failed, output: %q", result.Combined())
   466  
   467  	// Check subsequent unprivileged exec cannot mknod
   468  	icmd.RunCommand(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdc b 8 32").Assert(c, icmd.Expected{
   469  		ExitCode: 1,
   470  		Err:      "Operation not permitted",
   471  	})
   472  	// Confirm at no point was mknod allowed
   473  	result = icmd.RunCommand(dockerBinary, "logs", "parent")
   474  	result.Assert(c, icmd.Success)
   475  	assert.Assert(c, !strings.Contains(result.Combined(), "Success"))
   476  }
   477  
   478  func (s *DockerCLIExecSuite) TestExecWithImageUser(c *testing.T) {
   479  	// Not applicable on Windows
   480  	testRequires(c, DaemonIsLinux)
   481  	name := "testbuilduser"
   482  	buildImageSuccessfully(c, name, build.WithDockerfile(`FROM busybox
   483  		RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd
   484  		USER dockerio`))
   485  	dockerCmd(c, "run", "-d", "--name", "dockerioexec", name, "top")
   486  
   487  	out, _ := dockerCmd(c, "exec", "dockerioexec", "whoami")
   488  	assert.Assert(c, strings.Contains(out, "dockerio"), "exec with user by id expected dockerio user got %s", out)
   489  }
   490  
   491  func (s *DockerCLIExecSuite) TestExecOnReadonlyContainer(c *testing.T) {
   492  	// Windows does not support read-only
   493  	// --read-only + userns has remount issues
   494  	testRequires(c, DaemonIsLinux, NotUserNamespace)
   495  	dockerCmd(c, "run", "-d", "--read-only", "--name", "parent", "busybox", "top")
   496  	dockerCmd(c, "exec", "parent", "true")
   497  }
   498  
   499  func (s *DockerCLIExecSuite) TestExecUlimits(c *testing.T) {
   500  	testRequires(c, DaemonIsLinux)
   501  	name := "testexeculimits"
   502  	runSleepingContainer(c, "-d", "--ulimit", "nofile=511:511", "--name", name)
   503  	assert.NilError(c, waitRun(name))
   504  
   505  	out, _, err := dockerCmdWithError("exec", name, "sh", "-c", "ulimit -n")
   506  	assert.NilError(c, err)
   507  	assert.Equal(c, strings.TrimSpace(out), "511")
   508  }
   509  
   510  // #15750
   511  func (s *DockerCLIExecSuite) TestExecStartFails(c *testing.T) {
   512  	// TODO Windows CI. This test should be portable. Figure out why it fails
   513  	// currently.
   514  	testRequires(c, DaemonIsLinux)
   515  	name := "exec-15750"
   516  	runSleepingContainer(c, "-d", "--name", name)
   517  	assert.NilError(c, waitRun(name))
   518  
   519  	out, _, err := dockerCmdWithError("exec", name, "no-such-cmd")
   520  	assert.ErrorContains(c, err, "", out)
   521  	assert.Assert(c, strings.Contains(out, "executable file not found"))
   522  }
   523  
   524  // Fix regression in https://github.com/docker/docker/pull/26461#issuecomment-250287297
   525  func (s *DockerCLIExecSuite) TestExecWindowsPathNotWiped(c *testing.T) {
   526  	testRequires(c, DaemonIsWindows)
   527  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", minimalBaseImage(), "powershell", "start-sleep", "60")
   528  	assert.NilError(c, waitRun(strings.TrimSpace(out)))
   529  
   530  	out, _ = dockerCmd(c, "exec", "testing", "powershell", "write-host", "$env:PATH")
   531  	out = strings.ToLower(strings.Trim(out, "\r\n"))
   532  	assert.Assert(c, strings.Contains(out, `windowspowershell\v1.0`))
   533  }
   534  
   535  func (s *DockerCLIExecSuite) TestExecEnvLinksHost(c *testing.T) {
   536  	testRequires(c, DaemonIsLinux)
   537  	runSleepingContainer(c, "-d", "--name", "foo")
   538  	runSleepingContainer(c, "-d", "--link", "foo:db", "--hostname", "myhost", "--name", "bar")
   539  	out, _ := dockerCmd(c, "exec", "bar", "env")
   540  	assert.Check(c, is.Contains(out, "HOSTNAME=myhost"))
   541  	assert.Check(c, is.Contains(out, "DB_NAME=/bar/db"))
   542  }