github.com/wozhu6104/docker@v20.10.10+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  func (s *DockerSuite) TestExec(c *testing.T) {
    26  	testRequires(c, DaemonIsLinux)
    27  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    28  	assert.NilError(c, waitRun(strings.TrimSpace(out)))
    29  
    30  	out, _ = dockerCmd(c, "exec", "testing", "cat", "/tmp/file")
    31  	assert.Equal(c, strings.Trim(out, "\r\n"), "test")
    32  }
    33  
    34  func (s *DockerSuite) TestExecInteractive(c *testing.T) {
    35  	testRequires(c, DaemonIsLinux)
    36  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")
    37  
    38  	execCmd := exec.Command(dockerBinary, "exec", "-i", "testing", "sh")
    39  	stdin, err := execCmd.StdinPipe()
    40  	assert.NilError(c, err)
    41  	stdout, err := execCmd.StdoutPipe()
    42  	assert.NilError(c, err)
    43  
    44  	err = execCmd.Start()
    45  	assert.NilError(c, err)
    46  	_, err = stdin.Write([]byte("cat /tmp/file\n"))
    47  	assert.NilError(c, err)
    48  
    49  	r := bufio.NewReader(stdout)
    50  	line, err := r.ReadString('\n')
    51  	assert.NilError(c, err)
    52  	line = strings.TrimSpace(line)
    53  	assert.Equal(c, line, "test")
    54  	err = stdin.Close()
    55  	assert.NilError(c, err)
    56  	errChan := make(chan error, 1)
    57  	go func() {
    58  		errChan <- execCmd.Wait()
    59  		close(errChan)
    60  	}()
    61  	select {
    62  	case err := <-errChan:
    63  		assert.NilError(c, err)
    64  	case <-time.After(1 * time.Second):
    65  		c.Fatal("docker exec failed to exit on stdin close")
    66  	}
    67  
    68  }
    69  
    70  func (s *DockerSuite) TestExecAfterContainerRestart(c *testing.T) {
    71  	out := runSleepingContainer(c)
    72  	cleanedContainerID := strings.TrimSpace(out)
    73  	assert.NilError(c, waitRun(cleanedContainerID))
    74  	dockerCmd(c, "restart", cleanedContainerID)
    75  	assert.NilError(c, waitRun(cleanedContainerID))
    76  
    77  	out, _ = dockerCmd(c, "exec", cleanedContainerID, "echo", "hello")
    78  	assert.Equal(c, strings.TrimSpace(out), "hello")
    79  }
    80  
    81  func (s *DockerDaemonSuite) TestExecAfterDaemonRestart(c *testing.T) {
    82  	// TODO Windows CI: DockerDaemonSuite doesn't run on Windows, and requires a little work to get this ported.
    83  	s.d.StartWithBusybox(c)
    84  
    85  	out, err := s.d.Cmd("run", "-d", "--name", "top", "-p", "80", "busybox:latest", "top")
    86  	assert.NilError(c, err, "Could not run top: %s", out)
    87  
    88  	s.d.Restart(c)
    89  
    90  	out, err = s.d.Cmd("start", "top")
    91  	assert.NilError(c, err, "Could not start top after daemon restart: %s", out)
    92  
    93  	out, err = s.d.Cmd("exec", "top", "echo", "hello")
    94  	assert.NilError(c, err, "Could not exec on container top: %s", out)
    95  	assert.Equal(c, strings.TrimSpace(out), "hello")
    96  }
    97  
    98  // Regression test for #9155, #9044
    99  func (s *DockerSuite) TestExecEnv(c *testing.T) {
   100  	// TODO Windows CI: This one is interesting and may just end up being a feature
   101  	// difference between Windows and Linux. On Windows, the environment is passed
   102  	// into the process that is launched, not into the machine environment. Hence
   103  	// a subsequent exec will not have LALA set/
   104  	testRequires(c, DaemonIsLinux)
   105  	runSleepingContainer(c, "-e", "LALA=value1", "-e", "LALA=value2", "-d", "--name", "testing")
   106  	assert.NilError(c, waitRun("testing"))
   107  
   108  	out, _ := dockerCmd(c, "exec", "testing", "env")
   109  	assert.Check(c, !strings.Contains(out, "LALA=value1"))
   110  	assert.Check(c, strings.Contains(out, "LALA=value2"))
   111  	assert.Check(c, strings.Contains(out, "HOME=/root"))
   112  }
   113  
   114  func (s *DockerSuite) TestExecSetEnv(c *testing.T) {
   115  	testRequires(c, DaemonIsLinux)
   116  	runSleepingContainer(c, "-e", "HOME=/root", "-d", "--name", "testing")
   117  	assert.NilError(c, waitRun("testing"))
   118  
   119  	out, _ := dockerCmd(c, "exec", "-e", "HOME=/another", "-e", "ABC=xyz", "testing", "env")
   120  	assert.Check(c, !strings.Contains(out, "HOME=/root"))
   121  	assert.Check(c, strings.Contains(out, "HOME=/another"))
   122  	assert.Check(c, strings.Contains(out, "ABC=xyz"))
   123  }
   124  
   125  func (s *DockerSuite) TestExecExitStatus(c *testing.T) {
   126  	runSleepingContainer(c, "-d", "--name", "top")
   127  
   128  	result := icmd.RunCommand(dockerBinary, "exec", "top", "sh", "-c", "exit 23")
   129  	result.Assert(c, icmd.Expected{ExitCode: 23, Error: "exit status 23"})
   130  }
   131  
   132  func (s *DockerSuite) TestExecPausedContainer(c *testing.T) {
   133  	testRequires(c, IsPausable)
   134  
   135  	out := runSleepingContainer(c, "-d", "--name", "testing")
   136  	ContainerID := strings.TrimSpace(out)
   137  
   138  	dockerCmd(c, "pause", "testing")
   139  	out, _, err := dockerCmdWithError("exec", ContainerID, "echo", "hello")
   140  	assert.ErrorContains(c, err, "", "container should fail to exec new command if it is paused")
   141  
   142  	expected := ContainerID + " is paused, unpause the container before exec"
   143  	assert.Assert(c, is.Contains(out, expected), "container should not exec new command if it is paused")
   144  }
   145  
   146  // regression test for #9476
   147  func (s *DockerSuite) TestExecTTYCloseStdin(c *testing.T) {
   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  	assert.NilError(c, err)
   155  
   156  	stdinRw.Write([]byte("test"))
   157  	stdinRw.Close()
   158  
   159  	out, _, err := runCommandWithOutput(cmd)
   160  	assert.NilError(c, err, out)
   161  
   162  	out, _ = dockerCmd(c, "top", "exec_tty_stdin")
   163  	outArr := strings.Split(out, "\n")
   164  	assert.Assert(c, len(outArr) <= 3, "exec process left running")
   165  	assert.Assert(c, !strings.Contains(out, "nsenter-exec"))
   166  }
   167  
   168  func (s *DockerSuite) TestExecTTYWithoutStdin(c *testing.T) {
   169  	out, _ := dockerCmd(c, "run", "-d", "-ti", "busybox")
   170  	id := strings.TrimSpace(out)
   171  	assert.NilError(c, waitRun(id))
   172  
   173  	errChan := make(chan error, 1)
   174  	go func() {
   175  		defer close(errChan)
   176  
   177  		cmd := exec.Command(dockerBinary, "exec", "-ti", id, "true")
   178  		if _, err := cmd.StdinPipe(); err != nil {
   179  			errChan <- err
   180  			return
   181  		}
   182  
   183  		expected := "the input device is not a TTY"
   184  		if runtime.GOOS == "windows" {
   185  			expected += ".  If you are using mintty, try prefixing the command with 'winpty'"
   186  		}
   187  		if out, _, err := runCommandWithOutput(cmd); err == nil {
   188  			errChan <- fmt.Errorf("exec should have failed")
   189  			return
   190  		} else if !strings.Contains(out, expected) {
   191  			errChan <- fmt.Errorf("exec failed with error %q: expected %q", out, expected)
   192  			return
   193  		}
   194  	}()
   195  
   196  	select {
   197  	case err := <-errChan:
   198  		assert.NilError(c, err)
   199  	case <-time.After(3 * time.Second):
   200  		c.Fatal("exec is running but should have failed")
   201  	}
   202  }
   203  
   204  // FIXME(vdemeester) this should be a unit tests on cli/command/container package
   205  func (s *DockerSuite) TestExecParseError(c *testing.T) {
   206  	// TODO Windows CI: Requires some extra work. Consider copying the
   207  	// runSleepingContainer helper to have an exec version.
   208  	testRequires(c, DaemonIsLinux)
   209  	dockerCmd(c, "run", "-d", "--name", "top", "busybox", "top")
   210  
   211  	// Test normal (non-detached) case first
   212  	icmd.RunCommand(dockerBinary, "exec", "top").Assert(c, icmd.Expected{
   213  		ExitCode: 1,
   214  		Error:    "exit status 1",
   215  		Err:      "See 'docker exec --help'",
   216  	})
   217  }
   218  
   219  func (s *DockerSuite) TestExecStopNotHanging(c *testing.T) {
   220  	// TODO Windows CI: Requires some extra work. Consider copying the
   221  	// runSleepingContainer helper to have an exec version.
   222  	testRequires(c, DaemonIsLinux)
   223  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   224  
   225  	result := icmd.StartCmd(icmd.Command(dockerBinary, "exec", "testing", "top"))
   226  	result.Assert(c, icmd.Success)
   227  	go icmd.WaitOnCmd(0, result)
   228  
   229  	type dstop struct {
   230  		out string
   231  		err error
   232  	}
   233  	ch := make(chan dstop, 1)
   234  	go func() {
   235  		result := icmd.RunCommand(dockerBinary, "stop", "testing")
   236  		ch <- dstop{result.Combined(), result.Error}
   237  		close(ch)
   238  	}()
   239  	select {
   240  	case <-time.After(3 * time.Second):
   241  		c.Fatal("Container stop timed out")
   242  	case s := <-ch:
   243  		assert.NilError(c, s.err)
   244  	}
   245  }
   246  
   247  func (s *DockerSuite) TestExecCgroup(c *testing.T) {
   248  	// Not applicable on Windows - using Linux specific functionality
   249  	testRequires(c, NotUserNamespace)
   250  	testRequires(c, DaemonIsLinux)
   251  	dockerCmd(c, "run", "-d", "--name", "testing", "busybox", "top")
   252  
   253  	out, _ := dockerCmd(c, "exec", "testing", "cat", "/proc/1/cgroup")
   254  	containerCgroups := sort.StringSlice(strings.Split(out, "\n"))
   255  
   256  	var wg sync.WaitGroup
   257  	var mu sync.Mutex
   258  	var execCgroups []sort.StringSlice
   259  	errChan := make(chan error, 5)
   260  	// exec a few times concurrently to get consistent failure
   261  	for i := 0; i < 5; i++ {
   262  		wg.Add(1)
   263  		go func() {
   264  			defer wg.Done()
   265  			out, _, err := dockerCmdWithError("exec", "testing", "cat", "/proc/self/cgroup")
   266  			if err != nil {
   267  				errChan <- err
   268  				return
   269  			}
   270  			cg := sort.StringSlice(strings.Split(out, "\n"))
   271  
   272  			mu.Lock()
   273  			execCgroups = append(execCgroups, cg)
   274  			mu.Unlock()
   275  		}()
   276  	}
   277  	wg.Wait()
   278  	close(errChan)
   279  
   280  	for err := range errChan {
   281  		assert.NilError(c, err)
   282  	}
   283  
   284  	for _, cg := range execCgroups {
   285  		if !reflect.DeepEqual(cg, containerCgroups) {
   286  			fmt.Println("exec cgroups:")
   287  			for _, name := range cg {
   288  				fmt.Printf(" %s\n", name)
   289  			}
   290  
   291  			fmt.Println("container cgroups:")
   292  			for _, name := range containerCgroups {
   293  				fmt.Printf(" %s\n", name)
   294  			}
   295  			c.Fatal("cgroups mismatched")
   296  		}
   297  	}
   298  }
   299  
   300  func (s *DockerSuite) TestExecInspectID(c *testing.T) {
   301  	out := runSleepingContainer(c, "-d")
   302  	id := strings.TrimSuffix(out, "\n")
   303  
   304  	out = inspectField(c, id, "ExecIDs")
   305  	assert.Equal(c, out, "[]", "ExecIDs should be empty, got: %s", out)
   306  
   307  	// Start an exec, have it block waiting so we can do some checking
   308  	cmd := exec.Command(dockerBinary, "exec", id, "sh", "-c",
   309  		"while ! test -e /execid1; do sleep 1; done")
   310  
   311  	err := cmd.Start()
   312  	assert.NilError(c, err, "failed to start the exec cmd")
   313  
   314  	// Give the exec 10 chances/seconds to start then give up and stop the test
   315  	tries := 10
   316  	for i := 0; i < tries; i++ {
   317  		// Since its still running we should see exec as part of the container
   318  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   319  
   320  		if out != "[]" && out != "<no value>" {
   321  			break
   322  		}
   323  		assert.Check(c, i+1 != tries, "ExecIDs still empty after 10 second")
   324  		time.Sleep(1 * time.Second)
   325  	}
   326  
   327  	// Save execID for later
   328  	execID, err := inspectFilter(id, "index .ExecIDs 0")
   329  	assert.NilError(c, err, "failed to get the exec id")
   330  
   331  	// End the exec by creating the missing file
   332  	err = exec.Command(dockerBinary, "exec", id, "sh", "-c", "touch /execid1").Run()
   333  	assert.NilError(c, err, "failed to run the 2nd exec cmd")
   334  
   335  	// Wait for 1st exec to complete
   336  	cmd.Wait()
   337  
   338  	// Give the exec 10 chances/seconds to stop then give up and stop the test
   339  	for i := 0; i < tries; i++ {
   340  		// Since its still running we should see exec as part of the container
   341  		out = strings.TrimSpace(inspectField(c, id, "ExecIDs"))
   342  
   343  		if out == "[]" {
   344  			break
   345  		}
   346  		assert.Check(c, i+1 != tries, "ExecIDs still empty after 10 second")
   347  		time.Sleep(1 * time.Second)
   348  	}
   349  
   350  	// But we should still be able to query the execID
   351  	cli, err := client.NewClientWithOpts(client.FromEnv)
   352  	assert.NilError(c, err)
   353  	defer cli.Close()
   354  
   355  	_, err = cli.ContainerExecInspect(context.Background(), execID)
   356  	assert.NilError(c, err)
   357  
   358  	// Now delete the container and then an 'inspect' on the exec should
   359  	// result in a 404 (not 'container not running')
   360  	out, ec := dockerCmd(c, "rm", "-f", id)
   361  	assert.Equal(c, ec, 0, "error removing container: %s", out)
   362  
   363  	_, err = cli.ContainerExecInspect(context.Background(), execID)
   364  	assert.ErrorContains(c, err, "No such exec instance")
   365  }
   366  
   367  func (s *DockerSuite) TestLinksPingLinkedContainersOnRename(c *testing.T) {
   368  	// Problematic on Windows as Windows does not support links
   369  	testRequires(c, DaemonIsLinux)
   370  	var out string
   371  	out, _ = dockerCmd(c, "run", "-d", "--name", "container1", "busybox", "top")
   372  	idA := strings.TrimSpace(out)
   373  	assert.Assert(c, idA != "", "%s, id should not be nil", out)
   374  	out, _ = dockerCmd(c, "run", "-d", "--link", "container1:alias1", "--name", "container2", "busybox", "top")
   375  	idB := strings.TrimSpace(out)
   376  	assert.Assert(c, idB != "", "%s, id should not be nil", out)
   377  
   378  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   379  	dockerCmd(c, "rename", "container1", "container_new")
   380  	dockerCmd(c, "exec", "container2", "ping", "-c", "1", "alias1", "-W", "1")
   381  }
   382  
   383  func (s *DockerSuite) TestRunMutableNetworkFiles(c *testing.T) {
   384  	// Not applicable on Windows to Windows CI.
   385  	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)
   386  	for _, fn := range []string{"resolv.conf", "hosts"} {
   387  		containers := cli.DockerCmd(c, "ps", "-q", "-a").Combined()
   388  		if containers != "" {
   389  			cli.DockerCmd(c, append([]string{"rm", "-fv"}, strings.Split(strings.TrimSpace(containers), "\n")...)...)
   390  		}
   391  
   392  		content := runCommandAndReadContainerFile(c, fn, dockerBinary, "run", "-d", "--name", "c1", "busybox", "sh", "-c", fmt.Sprintf("echo success >/etc/%s && top", fn))
   393  
   394  		assert.Equal(c, strings.TrimSpace(string(content)), "success", "Content was not what was modified in the container", string(content))
   395  
   396  		out, _ := dockerCmd(c, "run", "-d", "--name", "c2", "busybox", "top")
   397  		contID := strings.TrimSpace(out)
   398  		netFilePath := containerStorageFile(contID, fn)
   399  
   400  		f, err := os.OpenFile(netFilePath, os.O_WRONLY|os.O_SYNC|os.O_APPEND, 0644)
   401  		assert.NilError(c, err)
   402  
   403  		if _, err := f.Seek(0, 0); err != nil {
   404  			f.Close()
   405  			c.Fatal(err)
   406  		}
   407  
   408  		if err := f.Truncate(0); err != nil {
   409  			f.Close()
   410  			c.Fatal(err)
   411  		}
   412  
   413  		if _, err := f.Write([]byte("success2\n")); err != nil {
   414  			f.Close()
   415  			c.Fatal(err)
   416  		}
   417  		f.Close()
   418  
   419  		res, _ := dockerCmd(c, "exec", contID, "cat", "/etc/"+fn)
   420  		assert.Equal(c, res, "success2\n")
   421  	}
   422  }
   423  
   424  func (s *DockerSuite) TestExecWithUser(c *testing.T) {
   425  	// TODO Windows CI: This may be fixable in the future once Windows
   426  	// supports users
   427  	testRequires(c, DaemonIsLinux)
   428  	dockerCmd(c, "run", "-d", "--name", "parent", "busybox", "top")
   429  
   430  	out, _ := dockerCmd(c, "exec", "-u", "1", "parent", "id")
   431  	assert.Assert(c, strings.Contains(out, "uid=1(daemon) gid=1(daemon)"))
   432  
   433  	out, _ = dockerCmd(c, "exec", "-u", "root", "parent", "id")
   434  	assert.Assert(c, strings.Contains(out, "uid=0(root) gid=0(root)"), "exec with user by id expected daemon user got %s", out)
   435  }
   436  
   437  func (s *DockerSuite) TestExecWithPrivileged(c *testing.T) {
   438  	// Not applicable on Windows
   439  	testRequires(c, DaemonIsLinux, NotUserNamespace)
   440  	// Start main loop which attempts mknod repeatedly
   441  	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`)
   442  
   443  	// Check exec mknod doesn't work
   444  	icmd.RunCommand(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdb b 8 16").Assert(c, icmd.Expected{
   445  		ExitCode: 1,
   446  		Err:      "Operation not permitted",
   447  	})
   448  
   449  	// Check exec mknod does work with --privileged
   450  	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`)
   451  	result.Assert(c, icmd.Success)
   452  
   453  	actual := strings.TrimSpace(result.Combined())
   454  	assert.Equal(c, actual, "ok", "exec mknod in --cap-drop=ALL container with --privileged failed, output: %q", result.Combined())
   455  
   456  	// Check subsequent unprivileged exec cannot mknod
   457  	icmd.RunCommand(dockerBinary, "exec", "parent", "sh", "-c", "mknod /tmp/sdc b 8 32").Assert(c, icmd.Expected{
   458  		ExitCode: 1,
   459  		Err:      "Operation not permitted",
   460  	})
   461  	// Confirm at no point was mknod allowed
   462  	result = icmd.RunCommand(dockerBinary, "logs", "parent")
   463  	result.Assert(c, icmd.Success)
   464  	assert.Assert(c, !strings.Contains(result.Combined(), "Success"))
   465  }
   466  
   467  func (s *DockerSuite) TestExecWithImageUser(c *testing.T) {
   468  	// Not applicable on Windows
   469  	testRequires(c, DaemonIsLinux)
   470  	name := "testbuilduser"
   471  	buildImageSuccessfully(c, name, build.WithDockerfile(`FROM busybox
   472  		RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd
   473  		USER dockerio`))
   474  	dockerCmd(c, "run", "-d", "--name", "dockerioexec", name, "top")
   475  
   476  	out, _ := dockerCmd(c, "exec", "dockerioexec", "whoami")
   477  	assert.Assert(c, strings.Contains(out, "dockerio"), "exec with user by id expected dockerio user got %s", out)
   478  }
   479  
   480  func (s *DockerSuite) TestExecOnReadonlyContainer(c *testing.T) {
   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 *testing.T) {
   489  	testRequires(c, DaemonIsLinux)
   490  	name := "testexeculimits"
   491  	runSleepingContainer(c, "-d", "--ulimit", "nofile=511:511", "--name", name)
   492  	assert.NilError(c, waitRun(name))
   493  
   494  	out, _, err := dockerCmdWithError("exec", name, "sh", "-c", "ulimit -n")
   495  	assert.NilError(c, err)
   496  	assert.Equal(c, strings.TrimSpace(out), "511")
   497  }
   498  
   499  // #15750
   500  func (s *DockerSuite) TestExecStartFails(c *testing.T) {
   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  	assert.NilError(c, waitRun(name))
   507  
   508  	out, _, err := dockerCmdWithError("exec", name, "no-such-cmd")
   509  	assert.ErrorContains(c, err, "", out)
   510  	assert.Assert(c, strings.Contains(out, "executable file not found"))
   511  }
   512  
   513  // Fix regression in https://github.com/docker/docker/pull/26461#issuecomment-250287297
   514  func (s *DockerSuite) TestExecWindowsPathNotWiped(c *testing.T) {
   515  	testRequires(c, DaemonIsWindows)
   516  	out, _ := dockerCmd(c, "run", "-d", "--name", "testing", minimalBaseImage(), "powershell", "start-sleep", "60")
   517  	assert.NilError(c, waitRun(strings.TrimSpace(out)))
   518  
   519  	out, _ = dockerCmd(c, "exec", "testing", "powershell", "write-host", "$env:PATH")
   520  	out = strings.ToLower(strings.Trim(out, "\r\n"))
   521  	assert.Assert(c, strings.Contains(out, `windowspowershell\v1.0`))
   522  }
   523  
   524  func (s *DockerSuite) TestExecEnvLinksHost(c *testing.T) {
   525  	testRequires(c, DaemonIsLinux)
   526  	runSleepingContainer(c, "-d", "--name", "foo")
   527  	runSleepingContainer(c, "-d", "--link", "foo:db", "--hostname", "myhost", "--name", "bar")
   528  	out, _ := dockerCmd(c, "exec", "bar", "env")
   529  	assert.Check(c, is.Contains(out, "HOSTNAME=myhost"))
   530  	assert.Check(c, is.Contains(out, "DB_NAME=/bar/db"))
   531  }