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moby--moby/integration-cli/docker_cli_cp_test.go
2020-02-11 00:06:42 +01:00

607 lines
21 KiB
Go

package main
import (
"bytes"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path"
"path/filepath"
"strings"
"testing"
"gotest.tools/v3/assert"
is "gotest.tools/v3/assert/cmp"
"gotest.tools/v3/icmd"
)
const (
cpTestPathParent = "/some"
cpTestPath = "/some/path"
cpTestName = "test"
cpFullPath = "/some/path/test"
cpContainerContents = "holla, i am the container"
cpHostContents = "hello, i am the host"
)
// Ensure that an all-local path case returns an error.
func (s *DockerSuite) TestCpLocalOnly(c *testing.T) {
err := runDockerCp(c, "foo", "bar")
assert.ErrorContains(c, err, "must specify at least one container source")
}
// Test for #5656
// Check that garbage paths don't escape the container's rootfs
func (s *DockerSuite) TestCpGarbagePath(c *testing.T) {
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath)
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
assert.NilError(c, os.MkdirAll(cpTestPath, os.ModeDir))
hostFile, err := os.Create(cpFullPath)
assert.NilError(c, err)
defer hostFile.Close()
defer os.RemoveAll(cpTestPathParent)
fmt.Fprintf(hostFile, "%s", cpHostContents)
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
tmpname := filepath.Join(tmpdir, cpTestName)
defer os.RemoveAll(tmpdir)
path := path.Join("../../../../../../../../../../../../", cpFullPath)
dockerCmd(c, "cp", containerID+":"+path, tmpdir)
file, _ := os.Open(tmpname)
defer file.Close()
test, err := ioutil.ReadAll(file)
assert.NilError(c, err)
assert.Assert(c, string(test) != cpHostContents, "output matched host file -- garbage path can escape container rootfs")
assert.Assert(c, string(test) == cpContainerContents, "output doesn't match the input for garbage path")
}
// Check that relative paths are relative to the container's rootfs
func (s *DockerSuite) TestCpRelativePath(c *testing.T) {
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath)
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
assert.NilError(c, os.MkdirAll(cpTestPath, os.ModeDir))
hostFile, err := os.Create(cpFullPath)
assert.NilError(c, err)
defer hostFile.Close()
defer os.RemoveAll(cpTestPathParent)
fmt.Fprintf(hostFile, "%s", cpHostContents)
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
tmpname := filepath.Join(tmpdir, cpTestName)
defer os.RemoveAll(tmpdir)
var relPath string
if path.IsAbs(cpFullPath) {
// normally this is `filepath.Rel("/", cpFullPath)` but we cannot
// get this unix-path manipulation on windows with filepath.
relPath = cpFullPath[1:]
}
assert.Assert(c, path.IsAbs(cpFullPath), "path %s was assumed to be an absolute path", cpFullPath)
dockerCmd(c, "cp", containerID+":"+relPath, tmpdir)
file, _ := os.Open(tmpname)
defer file.Close()
test, err := ioutil.ReadAll(file)
assert.NilError(c, err)
assert.Assert(c, string(test) != cpHostContents, "output matched host file -- relative path can escape container rootfs")
assert.Assert(c, string(test) == cpContainerContents, "output doesn't match the input for relative path")
}
// Check that absolute paths are relative to the container's rootfs
func (s *DockerSuite) TestCpAbsolutePath(c *testing.T) {
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath)
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
assert.NilError(c, os.MkdirAll(cpTestPath, os.ModeDir))
hostFile, err := os.Create(cpFullPath)
assert.NilError(c, err)
defer hostFile.Close()
defer os.RemoveAll(cpTestPathParent)
fmt.Fprintf(hostFile, "%s", cpHostContents)
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
tmpname := filepath.Join(tmpdir, cpTestName)
defer os.RemoveAll(tmpdir)
path := cpFullPath
dockerCmd(c, "cp", containerID+":"+path, tmpdir)
file, _ := os.Open(tmpname)
defer file.Close()
test, err := ioutil.ReadAll(file)
assert.NilError(c, err)
assert.Assert(c, string(test) != cpHostContents, "output matched host file -- absolute path can escape container rootfs")
assert.Assert(c, string(test) == cpContainerContents, "output doesn't match the input for absolute path")
}
// Test for #5619
// Check that absolute symlinks are still relative to the container's rootfs
func (s *DockerSuite) TestCpAbsoluteSymlink(c *testing.T) {
testRequires(c, DaemonIsLinux)
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpFullPath+" container_path")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
assert.NilError(c, os.MkdirAll(cpTestPath, os.ModeDir))
hostFile, err := os.Create(cpFullPath)
assert.NilError(c, err)
defer hostFile.Close()
defer os.RemoveAll(cpTestPathParent)
fmt.Fprintf(hostFile, "%s", cpHostContents)
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
tmpname := filepath.Join(tmpdir, "container_path")
defer os.RemoveAll(tmpdir)
path := path.Join("/", "container_path")
dockerCmd(c, "cp", containerID+":"+path, tmpdir)
// We should have copied a symlink *NOT* the file itself!
linkTarget, err := os.Readlink(tmpname)
assert.NilError(c, err)
assert.Equal(c, linkTarget, filepath.FromSlash(cpFullPath))
}
// Check that symlinks to a directory behave as expected when copying one from
// a container.
func (s *DockerSuite) TestCpFromSymlinkToDirectory(c *testing.T) {
testRequires(c, DaemonIsLinux)
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpTestPathParent+" /dir_link")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
testDir, err := ioutil.TempDir("", "test-cp-from-symlink-to-dir-")
assert.NilError(c, err)
defer os.RemoveAll(testDir)
// This copy command should copy the symlink, not the target, into the
// temporary directory.
dockerCmd(c, "cp", containerID+":"+"/dir_link", testDir)
expectedPath := filepath.Join(testDir, "dir_link")
linkTarget, err := os.Readlink(expectedPath)
assert.NilError(c, err)
assert.Equal(c, linkTarget, filepath.FromSlash(cpTestPathParent))
os.Remove(expectedPath)
// This copy command should resolve the symlink (note the trailing
// separator), copying the target into the temporary directory.
dockerCmd(c, "cp", containerID+":"+"/dir_link/", testDir)
// It *should not* have copied the directory using the target's name, but
// used the given name instead.
unexpectedPath := filepath.Join(testDir, cpTestPathParent)
stat, err := os.Lstat(unexpectedPath)
if err == nil {
out = fmt.Sprintf("target name was copied: %q - %q", stat.Mode(), stat.Name())
}
assert.ErrorContains(c, err, "", out)
// It *should* have copied the directory using the asked name "dir_link".
stat, err = os.Lstat(expectedPath)
assert.NilError(c, err, "unable to stat resource at %q", expectedPath)
assert.Assert(c, stat.IsDir(), "should have copied a directory but got %q instead", stat.Mode())
}
// Check that symlinks to a directory behave as expected when copying one to a
// container.
func (s *DockerSuite) TestCpToSymlinkToDirectory(c *testing.T) {
testRequires(c, DaemonIsLinux)
testRequires(c, testEnv.IsLocalDaemon) // Requires local volume mount bind.
testVol, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-")
assert.NilError(c, err)
defer os.RemoveAll(testVol)
// Create a test container with a local volume. We will test by copying
// to the volume path in the container which we can then verify locally.
out, _ := dockerCmd(c, "create", "-v", testVol+":/testVol", "busybox")
containerID := strings.TrimSpace(out)
// Create a temp directory to hold a test file nested in a directory.
testDir, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-")
assert.NilError(c, err)
defer os.RemoveAll(testDir)
// This file will be at "/testDir/some/path/test" and will be copied into
// the test volume later.
hostTestFilename := filepath.Join(testDir, cpFullPath)
assert.NilError(c, os.MkdirAll(filepath.Dir(hostTestFilename), os.FileMode(0700)))
assert.NilError(c, ioutil.WriteFile(hostTestFilename, []byte(cpHostContents), os.FileMode(0600)))
// Now create another temp directory to hold a symlink to the
// "/testDir/some" directory.
linkDir, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-")
assert.NilError(c, err)
defer os.RemoveAll(linkDir)
// Then symlink "/linkDir/dir_link" to "/testdir/some".
linkTarget := filepath.Join(testDir, cpTestPathParent)
localLink := filepath.Join(linkDir, "dir_link")
assert.NilError(c, os.Symlink(linkTarget, localLink))
// Now copy that symlink into the test volume in the container.
dockerCmd(c, "cp", localLink, containerID+":/testVol")
// This copy command should have copied the symlink *not* the target.
expectedPath := filepath.Join(testVol, "dir_link")
actualLinkTarget, err := os.Readlink(expectedPath)
assert.NilError(c, err, "unable to read symlink at %q", expectedPath)
assert.Equal(c, actualLinkTarget, linkTarget)
// Good, now remove that copied link for the next test.
os.Remove(expectedPath)
// This copy command should resolve the symlink (note the trailing
// separator), copying the target into the test volume directory in the
// container.
dockerCmd(c, "cp", localLink+"/", containerID+":/testVol")
// It *should not* have copied the directory using the target's name, but
// used the given name instead.
unexpectedPath := filepath.Join(testVol, cpTestPathParent)
stat, err := os.Lstat(unexpectedPath)
if err == nil {
out = fmt.Sprintf("target name was copied: %q - %q", stat.Mode(), stat.Name())
}
assert.ErrorContains(c, err, "", out)
// It *should* have copied the directory using the asked name "dir_link".
stat, err = os.Lstat(expectedPath)
assert.NilError(c, err, "unable to stat resource at %q", expectedPath)
assert.Assert(c, stat.IsDir(), "should have copied a directory but got %q instead", stat.Mode())
// And this directory should contain the file copied from the host at the
// expected location: "/testVol/dir_link/path/test"
expectedFilepath := filepath.Join(testVol, "dir_link/path/test")
fileContents, err := ioutil.ReadFile(expectedFilepath)
assert.NilError(c, err)
assert.Equal(c, string(fileContents), cpHostContents)
}
// Test for #5619
// Check that symlinks which are part of the resource path are still relative to the container's rootfs
func (s *DockerSuite) TestCpSymlinkComponent(c *testing.T) {
testRequires(c, DaemonIsLinux)
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpTestPath+" container_path")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
assert.NilError(c, os.MkdirAll(cpTestPath, os.ModeDir))
hostFile, err := os.Create(cpFullPath)
assert.NilError(c, err)
defer hostFile.Close()
defer os.RemoveAll(cpTestPathParent)
fmt.Fprintf(hostFile, "%s", cpHostContents)
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
tmpname := filepath.Join(tmpdir, cpTestName)
defer os.RemoveAll(tmpdir)
path := path.Join("/", "container_path", cpTestName)
dockerCmd(c, "cp", containerID+":"+path, tmpdir)
file, _ := os.Open(tmpname)
defer file.Close()
test, err := ioutil.ReadAll(file)
assert.NilError(c, err)
assert.Assert(c, string(test) != cpHostContents, "output matched host file -- symlink path component can escape container rootfs")
assert.Equal(c, string(test), cpContainerContents, "output doesn't match the input for symlink path component")
}
// Check that cp with unprivileged user doesn't return any error
func (s *DockerSuite) TestCpUnprivilegedUser(c *testing.T) {
testRequires(c, DaemonIsLinux, testEnv.IsLocalDaemon)
testRequires(c, UnixCli) // uses chmod/su: not available on windows
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "touch "+cpTestName)
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
defer os.RemoveAll(tmpdir)
err = os.Chmod(tmpdir, 0777)
assert.NilError(c, err)
result := icmd.RunCommand("su", "unprivilegeduser", "-c",
fmt.Sprintf("%s cp %s:%s %s", dockerBinary, containerID, cpTestName, tmpdir))
result.Assert(c, icmd.Expected{})
}
func (s *DockerSuite) TestCpSpecialFiles(c *testing.T) {
testRequires(c, DaemonIsLinux)
testRequires(c, testEnv.IsLocalDaemon)
outDir, err := ioutil.TempDir("", "cp-test-special-files")
assert.NilError(c, err)
defer os.RemoveAll(outDir)
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "touch /foo")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
// Copy actual /etc/resolv.conf
dockerCmd(c, "cp", containerID+":/etc/resolv.conf", outDir)
expected := readContainerFile(c, containerID, "resolv.conf")
actual, err := ioutil.ReadFile(outDir + "/resolv.conf")
assert.NilError(c, err)
assert.Assert(c, bytes.Equal(actual, expected), "Expected copied file to be duplicate of the container resolvconf")
// Copy actual /etc/hosts
dockerCmd(c, "cp", containerID+":/etc/hosts", outDir)
expected = readContainerFile(c, containerID, "hosts")
actual, err = ioutil.ReadFile(outDir + "/hosts")
assert.NilError(c, err)
assert.Assert(c, bytes.Equal(actual, expected), "Expected copied file to be duplicate of the container hosts")
// Copy actual /etc/resolv.conf
dockerCmd(c, "cp", containerID+":/etc/hostname", outDir)
expected = readContainerFile(c, containerID, "hostname")
actual, err = ioutil.ReadFile(outDir + "/hostname")
assert.NilError(c, err)
assert.Assert(c, bytes.Equal(actual, expected), "Expected copied file to be duplicate of the container hostname")
}
func (s *DockerSuite) TestCpVolumePath(c *testing.T) {
// stat /tmp/cp-test-volumepath851508420/test gets permission denied for the user
testRequires(c, NotUserNamespace)
testRequires(c, DaemonIsLinux)
testRequires(c, testEnv.IsLocalDaemon)
tmpDir, err := ioutil.TempDir("", "cp-test-volumepath")
assert.NilError(c, err)
defer os.RemoveAll(tmpDir)
outDir, err := ioutil.TempDir("", "cp-test-volumepath-out")
assert.NilError(c, err)
defer os.RemoveAll(outDir)
_, err = os.Create(tmpDir + "/test")
assert.NilError(c, err)
out, _ := dockerCmd(c, "run", "-d", "-v", "/foo", "-v", tmpDir+"/test:/test", "-v", tmpDir+":/baz", "busybox", "/bin/sh", "-c", "touch /foo/bar")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
// Copy actual volume path
dockerCmd(c, "cp", containerID+":/foo", outDir)
stat, err := os.Stat(outDir + "/foo")
assert.NilError(c, err)
assert.Assert(c, stat.IsDir(), "Expected copied content to be dir")
stat, err = os.Stat(outDir + "/foo/bar")
assert.NilError(c, err)
assert.Assert(c, !stat.IsDir(), "Expected file `bar` to be a file")
// Copy file nested in volume
dockerCmd(c, "cp", containerID+":/foo/bar", outDir)
stat, err = os.Stat(outDir + "/bar")
assert.NilError(c, err)
assert.Assert(c, !stat.IsDir(), "Expected file `bar` to be a file")
// Copy Bind-mounted dir
dockerCmd(c, "cp", containerID+":/baz", outDir)
stat, err = os.Stat(outDir + "/baz")
assert.NilError(c, err)
assert.Assert(c, stat.IsDir(), "Expected `baz` to be a dir")
// Copy file nested in bind-mounted dir
dockerCmd(c, "cp", containerID+":/baz/test", outDir)
fb, err := ioutil.ReadFile(outDir + "/baz/test")
assert.NilError(c, err)
fb2, err := ioutil.ReadFile(tmpDir + "/test")
assert.NilError(c, err)
assert.Assert(c, bytes.Equal(fb, fb2), "Expected copied file to be duplicate of bind-mounted file")
// Copy bind-mounted file
dockerCmd(c, "cp", containerID+":/test", outDir)
fb, err = ioutil.ReadFile(outDir + "/test")
assert.NilError(c, err)
fb2, err = ioutil.ReadFile(tmpDir + "/test")
assert.NilError(c, err)
assert.Assert(c, bytes.Equal(fb, fb2), "Expected copied file to be duplicate of bind-mounted file")
}
func (s *DockerSuite) TestCpToDot(c *testing.T) {
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
defer os.RemoveAll(tmpdir)
cwd, err := os.Getwd()
assert.NilError(c, err)
defer os.Chdir(cwd)
err = os.Chdir(tmpdir)
assert.NilError(c, err)
dockerCmd(c, "cp", containerID+":/test", ".")
content, err := ioutil.ReadFile("./test")
assert.NilError(c, err)
assert.Equal(c, string(content), "lololol\n")
}
func (s *DockerSuite) TestCpToStdout(c *testing.T) {
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
out, err := RunCommandPipelineWithOutput(
exec.Command(dockerBinary, "cp", containerID+":/test", "-"),
exec.Command("tar", "-vtf", "-"))
assert.NilError(c, err)
assert.Check(c, is.Contains(out, "test"))
assert.Check(c, is.Contains(out, "-rw"))
}
func (s *DockerSuite) TestCpNameHasColon(c *testing.T) {
testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)
out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /te:s:t")
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
tmpdir, err := ioutil.TempDir("", "docker-integration")
assert.NilError(c, err)
defer os.RemoveAll(tmpdir)
dockerCmd(c, "cp", containerID+":/te:s:t", tmpdir)
content, err := ioutil.ReadFile(tmpdir + "/te:s:t")
assert.NilError(c, err)
assert.Equal(c, string(content), "lololol\n")
}
func (s *DockerSuite) TestCopyAndRestart(c *testing.T) {
testRequires(c, DaemonIsLinux)
expectedMsg := "hello"
out, _ := dockerCmd(c, "run", "-d", "busybox", "echo", expectedMsg)
containerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", containerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
tmpDir, err := ioutil.TempDir("", "test-docker-restart-after-copy-")
assert.NilError(c, err)
defer os.RemoveAll(tmpDir)
dockerCmd(c, "cp", fmt.Sprintf("%s:/etc/group", containerID), tmpDir)
out, _ = dockerCmd(c, "start", "-a", containerID)
assert.Equal(c, strings.TrimSpace(out), expectedMsg)
}
func (s *DockerSuite) TestCopyCreatedContainer(c *testing.T) {
testRequires(c, DaemonIsLinux)
dockerCmd(c, "create", "--name", "test_cp", "-v", "/test", "busybox")
tmpDir, err := ioutil.TempDir("", "test")
assert.NilError(c, err)
defer os.RemoveAll(tmpDir)
dockerCmd(c, "cp", "test_cp:/bin/sh", tmpDir)
}
// test copy with option `-L`: following symbol link
// Check that symlinks to a file behave as expected when copying one from
// a container to host following symbol link
func (s *DockerSuite) TestCpSymlinkFromConToHostFollowSymlink(c *testing.T) {
testRequires(c, DaemonIsLinux)
out, exitCode := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpFullPath+" /dir_link")
assert.Equal(c, exitCode, 0, "failed to set up container: %s", out)
cleanedContainerID := strings.TrimSpace(out)
out, _ = dockerCmd(c, "wait", cleanedContainerID)
assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container")
testDir, err := ioutil.TempDir("", "test-cp-symlink-container-to-host-follow-symlink")
assert.NilError(c, err)
defer os.RemoveAll(testDir)
// This copy command should copy the symlink, not the target, into the
// temporary directory.
dockerCmd(c, "cp", "-L", cleanedContainerID+":"+"/dir_link", testDir)
expectedPath := filepath.Join(testDir, "dir_link")
expected := []byte(cpContainerContents)
actual, err := ioutil.ReadFile(expectedPath)
assert.NilError(c, err)
os.Remove(expectedPath)
assert.Assert(c, bytes.Equal(actual, expected), "Expected copied file to be duplicate of the container symbol link target")
// now test copy symbol link to a non-existing file in host
expectedPath = filepath.Join(testDir, "somefile_host")
// expectedPath shouldn't exist, if exists, remove it
if _, err := os.Lstat(expectedPath); err == nil {
os.Remove(expectedPath)
}
dockerCmd(c, "cp", "-L", cleanedContainerID+":"+"/dir_link", expectedPath)
actual, err = ioutil.ReadFile(expectedPath)
assert.NilError(c, err)
defer os.Remove(expectedPath)
assert.Assert(c, bytes.Equal(actual, expected), "Expected copied file to be duplicate of the container symbol link target")
}