package main import ( "bytes" "fmt" "io/ioutil" "os" "os/exec" "path" "path/filepath" "strings" "github.com/docker/docker/pkg/integration/checker" "github.com/go-check/check" ) 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 *check.C) { err := runDockerCp(c, "foo", "bar") c.Assert(err, checker.NotNil) c.Assert(err.Error(), checker.Contains, "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 *check.C) { testRequires(c, DaemonIsLinux) 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") c.Assert(os.MkdirAll(cpTestPath, os.ModeDir), checker.IsNil) hostFile, err := os.Create(cpFullPath) c.Assert(err, checker.IsNil) defer hostFile.Close() defer os.RemoveAll(cpTestPathParent) fmt.Fprintf(hostFile, "%s", cpHostContents) tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) 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) c.Assert(err, checker.IsNil) // output matched host file -- garbage path can escape container rootfs c.Assert(string(test), checker.Not(checker.Equals), cpHostContents) // output doesn't match the input for garbage path c.Assert(string(test), checker.Equals, cpContainerContents) } // Check that relative paths are relative to the container's rootfs func (s *DockerSuite) TestCpRelativePath(c *check.C) { testRequires(c, DaemonIsLinux) 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") c.Assert(os.MkdirAll(cpTestPath, os.ModeDir), checker.IsNil) hostFile, err := os.Create(cpFullPath) c.Assert(err, checker.IsNil) defer hostFile.Close() defer os.RemoveAll(cpTestPathParent) fmt.Fprintf(hostFile, "%s", cpHostContents) tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) 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:] } c.Assert(path.IsAbs(cpFullPath), checker.True, check.Commentf("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) c.Assert(err, checker.IsNil) // output matched host file -- relative path can escape container rootfs c.Assert(string(test), checker.Not(checker.Equals), cpHostContents) // output doesn't match the input for relative path c.Assert(string(test), checker.Equals, cpContainerContents) } // Check that absolute paths are relative to the container's rootfs func (s *DockerSuite) TestCpAbsolutePath(c *check.C) { testRequires(c, DaemonIsLinux) 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") c.Assert(os.MkdirAll(cpTestPath, os.ModeDir), checker.IsNil) hostFile, err := os.Create(cpFullPath) c.Assert(err, checker.IsNil) defer hostFile.Close() defer os.RemoveAll(cpTestPathParent) fmt.Fprintf(hostFile, "%s", cpHostContents) tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) 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) c.Assert(err, checker.IsNil) // output matched host file -- absolute path can escape container rootfs c.Assert(string(test), checker.Not(checker.Equals), cpHostContents) // output doesn't match the input for absolute path c.Assert(string(test), checker.Equals, cpContainerContents) } // Test for #5619 // Check that absolute symlinks are still relative to the container's rootfs func (s *DockerSuite) TestCpAbsoluteSymlink(c *check.C) { 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") c.Assert(os.MkdirAll(cpTestPath, os.ModeDir), checker.IsNil) hostFile, err := os.Create(cpFullPath) c.Assert(err, checker.IsNil) defer hostFile.Close() defer os.RemoveAll(cpTestPathParent) fmt.Fprintf(hostFile, "%s", cpHostContents) tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) 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) c.Assert(err, checker.IsNil) c.Assert(linkTarget, checker.Equals, filepath.FromSlash(cpFullPath)) } // Check that symlinks to a directory behave as expected when copying one from // a container. func (s *DockerSuite) TestCpFromSymlinkToDirectory(c *check.C) { 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") testDir, err := ioutil.TempDir("", "test-cp-from-symlink-to-dir-") c.Assert(err, checker.IsNil) 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) c.Assert(err, checker.IsNil) c.Assert(linkTarget, checker.Equals, 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()) } c.Assert(err, checker.NotNil, check.Commentf(out)) // It *should* have copied the directory using the asked name "dir_link". stat, err = os.Lstat(expectedPath) c.Assert(err, checker.IsNil, check.Commentf("unable to stat resource at %q", expectedPath)) c.Assert(stat.IsDir(), checker.True, check.Commentf("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 *check.C) { testRequires(c, DaemonIsLinux) testRequires(c, SameHostDaemon) // Requires local volume mount bind. testVol, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-") c.Assert(err, checker.IsNil) 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 direcotry. testDir, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-") c.Assert(err, checker.IsNil) 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) c.Assert(os.MkdirAll(filepath.Dir(hostTestFilename), os.FileMode(0700)), checker.IsNil) c.Assert(ioutil.WriteFile(hostTestFilename, []byte(cpHostContents), os.FileMode(0600)), checker.IsNil) // Now create another temp directory to hold a symlink to the // "/testDir/some" directory. linkDir, err := ioutil.TempDir("", "test-cp-to-symlink-to-dir-") c.Assert(err, checker.IsNil) defer os.RemoveAll(linkDir) // Then symlink "/linkDir/dir_link" to "/testdir/some". linkTarget := filepath.Join(testDir, cpTestPathParent) localLink := filepath.Join(linkDir, "dir_link") c.Assert(os.Symlink(linkTarget, localLink), checker.IsNil) // 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) c.Assert(err, checker.IsNil, check.Commentf("unable to read symlink at %q", expectedPath)) c.Assert(actualLinkTarget, checker.Equals, 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()) } c.Assert(err, checker.NotNil, check.Commentf(out)) // It *should* have copied the directory using the asked name "dir_link". stat, err = os.Lstat(expectedPath) c.Assert(err, checker.IsNil, check.Commentf("unable to stat resource at %q", expectedPath)) c.Assert(stat.IsDir(), checker.True, check.Commentf("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) c.Assert(err, checker.IsNil) c.Assert(string(fileContents), checker.Equals, 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 *check.C) { 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") c.Assert(os.MkdirAll(cpTestPath, os.ModeDir), checker.IsNil) hostFile, err := os.Create(cpFullPath) c.Assert(err, checker.IsNil) defer hostFile.Close() defer os.RemoveAll(cpTestPathParent) fmt.Fprintf(hostFile, "%s", cpHostContents) tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) 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) c.Assert(err, checker.IsNil) // output matched host file -- symlink path component can escape container rootfs c.Assert(string(test), checker.Not(checker.Equals), cpHostContents) // output doesn't match the input for symlink path component c.Assert(string(test), checker.Equals, cpContainerContents) } // Check that cp with unprivileged user doesn't return any error func (s *DockerSuite) TestCpUnprivilegedUser(c *check.C) { testRequires(c, DaemonIsLinux) 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) defer os.RemoveAll(tmpdir) c.Assert(os.Chmod(tmpdir, 0777), checker.IsNil) path := cpTestName _, _, err = runCommandWithOutput(exec.Command("su", "unprivilegeduser", "-c", dockerBinary+" cp "+containerID+":"+path+" "+tmpdir)) c.Assert(err, checker.IsNil, check.Commentf("couldn't copy with unprivileged user: %s:%s", containerID, path)) } func (s *DockerSuite) TestCpSpecialFiles(c *check.C) { testRequires(c, DaemonIsLinux) testRequires(c, SameHostDaemon) outDir, err := ioutil.TempDir("", "cp-test-special-files") c.Assert(err, checker.IsNil) defer os.RemoveAll(outDir) out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "touch /foo") containerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", containerID) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") // Copy actual /etc/resolv.conf dockerCmd(c, "cp", containerID+":/etc/resolv.conf", outDir) expected, err := readContainerFile(containerID, "resolv.conf") actual, err := ioutil.ReadFile(outDir + "/resolv.conf") // Expected copied file to be duplicate of the container resolvconf c.Assert(bytes.Equal(actual, expected), checker.True) // Copy actual /etc/hosts dockerCmd(c, "cp", containerID+":/etc/hosts", outDir) expected, err = readContainerFile(containerID, "hosts") actual, err = ioutil.ReadFile(outDir + "/hosts") // Expected copied file to be duplicate of the container hosts c.Assert(bytes.Equal(actual, expected), checker.True) // Copy actual /etc/resolv.conf dockerCmd(c, "cp", containerID+":/etc/hostname", outDir) expected, err = readContainerFile(containerID, "hostname") actual, err = ioutil.ReadFile(outDir + "/hostname") // Expected copied file to be duplicate of the container resolvconf c.Assert(bytes.Equal(actual, expected), checker.True) } func (s *DockerSuite) TestCpVolumePath(c *check.C) { // stat /tmp/cp-test-volumepath851508420/test gets permission denied for the user testRequires(c, NotUserNamespace) testRequires(c, DaemonIsLinux) testRequires(c, SameHostDaemon) tmpDir, err := ioutil.TempDir("", "cp-test-volumepath") c.Assert(err, checker.IsNil) defer os.RemoveAll(tmpDir) outDir, err := ioutil.TempDir("", "cp-test-volumepath-out") c.Assert(err, checker.IsNil) defer os.RemoveAll(outDir) _, err = os.Create(tmpDir + "/test") c.Assert(err, checker.IsNil) 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) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") // Copy actual volume path dockerCmd(c, "cp", containerID+":/foo", outDir) stat, err := os.Stat(outDir + "/foo") c.Assert(err, checker.IsNil) // expected copied content to be dir c.Assert(stat.IsDir(), checker.True) stat, err = os.Stat(outDir + "/foo/bar") c.Assert(err, checker.IsNil) // Expected file `bar` to be a file c.Assert(stat.IsDir(), checker.False) // Copy file nested in volume dockerCmd(c, "cp", containerID+":/foo/bar", outDir) stat, err = os.Stat(outDir + "/bar") c.Assert(err, checker.IsNil) // Expected file `bar` to be a file c.Assert(stat.IsDir(), checker.False) // Copy Bind-mounted dir dockerCmd(c, "cp", containerID+":/baz", outDir) stat, err = os.Stat(outDir + "/baz") c.Assert(err, checker.IsNil) // Expected `baz` to be a dir c.Assert(stat.IsDir(), checker.True) // Copy file nested in bind-mounted dir dockerCmd(c, "cp", containerID+":/baz/test", outDir) fb, err := ioutil.ReadFile(outDir + "/baz/test") c.Assert(err, checker.IsNil) fb2, err := ioutil.ReadFile(tmpDir + "/test") c.Assert(err, checker.IsNil) // Expected copied file to be duplicate of bind-mounted file c.Assert(bytes.Equal(fb, fb2), checker.True) // Copy bind-mounted file dockerCmd(c, "cp", containerID+":/test", outDir) fb, err = ioutil.ReadFile(outDir + "/test") c.Assert(err, checker.IsNil) fb2, err = ioutil.ReadFile(tmpDir + "/test") c.Assert(err, checker.IsNil) // Expected copied file to be duplicate of bind-mounted file c.Assert(bytes.Equal(fb, fb2), checker.True) } func (s *DockerSuite) TestCpToDot(c *check.C) { testRequires(c, DaemonIsLinux) out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test") containerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", containerID) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) defer os.RemoveAll(tmpdir) cwd, err := os.Getwd() c.Assert(err, checker.IsNil) defer os.Chdir(cwd) c.Assert(os.Chdir(tmpdir), checker.IsNil) dockerCmd(c, "cp", containerID+":/test", ".") content, err := ioutil.ReadFile("./test") c.Assert(string(content), checker.Equals, "lololol\n") } func (s *DockerSuite) TestCpToStdout(c *check.C) { testRequires(c, DaemonIsLinux) out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test") containerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", containerID) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") out, _, err := runCommandPipelineWithOutput( exec.Command(dockerBinary, "cp", containerID+":/test", "-"), exec.Command("tar", "-vtf", "-")) c.Assert(err, checker.IsNil) c.Assert(out, checker.Contains, "test") c.Assert(out, checker.Contains, "-rw") } func (s *DockerSuite) TestCpNameHasColon(c *check.C) { testRequires(c, SameHostDaemon) out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /te:s:t") containerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", containerID) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") tmpdir, err := ioutil.TempDir("", "docker-integration") c.Assert(err, checker.IsNil) defer os.RemoveAll(tmpdir) dockerCmd(c, "cp", containerID+":/te:s:t", tmpdir) content, err := ioutil.ReadFile(tmpdir + "/te:s:t") c.Assert(string(content), checker.Equals, "lololol\n") } func (s *DockerSuite) TestCopyAndRestart(c *check.C) { testRequires(c, DaemonIsLinux) expectedMsg := "hello" out, _ := dockerCmd(c, "run", "-d", "busybox", "echo", expectedMsg) containerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", containerID) // failed to set up container c.Assert(strings.TrimSpace(out), checker.Equals, "0") tmpDir, err := ioutil.TempDir("", "test-docker-restart-after-copy-") c.Assert(err, checker.IsNil) defer os.RemoveAll(tmpDir) dockerCmd(c, "cp", fmt.Sprintf("%s:/etc/group", containerID), tmpDir) out, _ = dockerCmd(c, "start", "-a", containerID) c.Assert(strings.TrimSpace(out), checker.Equals, expectedMsg) } func (s *DockerSuite) TestCopyCreatedContainer(c *check.C) { testRequires(c, DaemonIsLinux) dockerCmd(c, "create", "--name", "test_cp", "-v", "/test", "busybox") tmpDir, err := ioutil.TempDir("", "test") c.Assert(err, checker.IsNil) 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 *check.C) { 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") if exitCode != 0 { c.Fatal("failed to create a container", out) } cleanedContainerID := strings.TrimSpace(out) out, _ = dockerCmd(c, "wait", cleanedContainerID) if strings.TrimSpace(out) != "0" { c.Fatal("failed to set up container", out) } testDir, err := ioutil.TempDir("", "test-cp-symlink-container-to-host-follow-symlink") if err != nil { c.Fatal(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) if !bytes.Equal(actual, expected) { c.Fatalf("Expected copied file to be duplicate of the container symbol link target") } os.Remove(expectedPath) // now test copy symbol link to an 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) if !bytes.Equal(actual, expected) { c.Fatalf("Expected copied file to be duplicate of the container symbol link target") } defer os.Remove(expectedPath) }