package main import ( "bytes" "context" "fmt" "io" "os" "os/exec" "path" "path/filepath" "strings" "testing" "github.com/docker/docker/integration-cli/cli" "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" ) type DockerCLICpSuite struct { ds *DockerSuite } func (s *DockerCLICpSuite) TearDownTest(ctx context.Context, c *testing.T) { s.ds.TearDownTest(ctx, c) } func (s *DockerCLICpSuite) OnTimeout(c *testing.T) { s.ds.OnTimeout(c) } // Ensure that an all-local path case returns an error. func (s *DockerCLICpSuite) 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 *DockerCLICpSuite) TestCpGarbagePath(c *testing.T) { containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath).Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) tmpname := filepath.Join(tmpdir, cpTestName) defer os.RemoveAll(tmpdir) containerPath := path.Join("../../../../../../../../../../../../", cpFullPath) cli.DockerCmd(c, "cp", containerID+":"+containerPath, tmpdir) file, _ := os.Open(tmpname) defer file.Close() test, err := io.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 *DockerCLICpSuite) TestCpRelativePath(c *testing.T) { containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath).Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 := os.MkdirTemp("", "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) cli.DockerCmd(c, "cp", containerID+":"+relPath, tmpdir) file, _ := os.Open(tmpname) defer file.Close() test, err := io.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 *DockerCLICpSuite) TestCpAbsolutePath(c *testing.T) { containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath).Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) tmpname := filepath.Join(tmpdir, cpTestName) defer os.RemoveAll(tmpdir) cli.DockerCmd(c, "cp", containerID+":"+cpFullPath, tmpdir) file, _ := os.Open(tmpname) defer file.Close() test, err := io.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 *DockerCLICpSuite) TestCpAbsoluteSymlink(c *testing.T) { testRequires(c, DaemonIsLinux) containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpFullPath+" container_path").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) tmpname := filepath.Join(tmpdir, "container_path") defer os.RemoveAll(tmpdir) containerPath := path.Join("/", "container_path") cli.DockerCmd(c, "cp", containerID+":"+containerPath, 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 *DockerCLICpSuite) TestCpFromSymlinkToDirectory(c *testing.T) { testRequires(c, DaemonIsLinux) containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpTestPathParent+" /dir_link").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") testDir, err := os.MkdirTemp("", "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. cli.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. cli.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 *DockerCLICpSuite) TestCpToSymlinkToDirectory(c *testing.T) { testRequires(c, DaemonIsLinux) testRequires(c, testEnv.IsLocalDaemon) // Requires local volume mount bind. testVol, err := os.MkdirTemp("", "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. containerID := cli.DockerCmd(c, "create", "-v", testVol+":/testVol", "busybox").Stdout() containerID = strings.TrimSpace(containerID) // Create a temp directory to hold a test file nested in a directory. testDir, err := os.MkdirTemp("", "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(0o700))) assert.NilError(c, os.WriteFile(hostTestFilename, []byte(cpHostContents), os.FileMode(0o600))) // Now create another temp directory to hold a symlink to the // "/testDir/some" directory. linkDir, err := os.MkdirTemp("", "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. cli.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. cli.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 { c.Errorf("target name was unexpectedly preserved: %q - %q", stat.Mode(), stat.Name()) } // 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 := os.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 *DockerCLICpSuite) TestCpSymlinkComponent(c *testing.T) { testRequires(c, DaemonIsLinux) containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpTestPath+" container_path").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) tmpname := filepath.Join(tmpdir, cpTestName) defer os.RemoveAll(tmpdir) containerPath := path.Join("/", "container_path", cpTestName) cli.DockerCmd(c, "cp", containerID+":"+containerPath, tmpdir) file, _ := os.Open(tmpname) defer file.Close() test, err := io.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 *DockerCLICpSuite) TestCpUnprivilegedUser(c *testing.T) { testRequires(c, DaemonIsLinux, testEnv.IsLocalDaemon) testRequires(c, UnixCli) // uses chmod/su: not available on windows containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "touch "+cpTestName).Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") tmpdir, err := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) defer os.RemoveAll(tmpdir) err = os.Chmod(tmpdir, 0o777) 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 *DockerCLICpSuite) TestCpSpecialFiles(c *testing.T) { testRequires(c, DaemonIsLinux) testRequires(c, testEnv.IsLocalDaemon) outDir, err := os.MkdirTemp("", "cp-test-special-files") assert.NilError(c, err) defer os.RemoveAll(outDir) containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "touch /foo").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") // Copy actual /etc/resolv.conf cli.DockerCmd(c, "cp", containerID+":/etc/resolv.conf", outDir) expected := readContainerFile(c, containerID, "resolv.conf") actual, err := os.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 cli.DockerCmd(c, "cp", containerID+":/etc/hosts", outDir) expected = readContainerFile(c, containerID, "hosts") actual, err = os.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 cli.DockerCmd(c, "cp", containerID+":/etc/hostname", outDir) expected = readContainerFile(c, containerID, "hostname") actual, err = os.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 *DockerCLICpSuite) 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 := os.MkdirTemp("", "cp-test-volumepath") assert.NilError(c, err) defer os.RemoveAll(tmpDir) outDir, err := os.MkdirTemp("", "cp-test-volumepath-out") assert.NilError(c, err) defer os.RemoveAll(outDir) _, err = os.Create(tmpDir + "/test") assert.NilError(c, err) containerID := cli.DockerCmd(c, "run", "-d", "-v", "/foo", "-v", tmpDir+"/test:/test", "-v", tmpDir+":/baz", "busybox", "/bin/sh", "-c", "touch /foo/bar").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") // Copy actual volume path cli.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 cli.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 cli.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 cli.DockerCmd(c, "cp", containerID+":/baz/test", outDir) fb, err := os.ReadFile(outDir + "/baz/test") assert.NilError(c, err) fb2, err := os.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 cli.DockerCmd(c, "cp", containerID+":/test", outDir) fb, err = os.ReadFile(outDir + "/test") assert.NilError(c, err) fb2, err = os.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 *DockerCLICpSuite) TestCpToDot(c *testing.T) { containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") tmpdir, err := os.MkdirTemp("", "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) cli.DockerCmd(c, "cp", containerID+":/test", ".") content, err := os.ReadFile("./test") assert.NilError(c, err) assert.Equal(c, string(content), "lololol\n") } func (s *DockerCLICpSuite) TestCpToStdout(c *testing.T) { containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /test").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() 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 *DockerCLICpSuite) TestCpNameHasColon(c *testing.T) { testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux) containerID := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "echo lololol > /te:s:t").Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") tmpdir, err := os.MkdirTemp("", "docker-integration") assert.NilError(c, err) defer os.RemoveAll(tmpdir) cli.DockerCmd(c, "cp", containerID+":/te:s:t", tmpdir) content, err := os.ReadFile(tmpdir + "/te:s:t") assert.NilError(c, err) assert.Equal(c, string(content), "lololol\n") } func (s *DockerCLICpSuite) TestCopyAndRestart(c *testing.T) { testRequires(c, DaemonIsLinux) const expectedMsg = "hello" containerID := cli.DockerCmd(c, "run", "-d", "busybox", "echo", expectedMsg).Stdout() containerID = strings.TrimSpace(containerID) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") tmpDir, err := os.MkdirTemp("", "test-docker-restart-after-copy-") assert.NilError(c, err) defer os.RemoveAll(tmpDir) cli.DockerCmd(c, "cp", fmt.Sprintf("%s:/etc/group", containerID), tmpDir) out = cli.DockerCmd(c, "start", "-a", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), expectedMsg) } func (s *DockerCLICpSuite) TestCopyCreatedContainer(c *testing.T) { testRequires(c, DaemonIsLinux) cli.DockerCmd(c, "create", "--name", "test_cp", "-v", "/test", "busybox") tmpDir, err := os.MkdirTemp("", "test") assert.NilError(c, err) defer os.RemoveAll(tmpDir) cli.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 *DockerCLICpSuite) TestCpSymlinkFromConToHostFollowSymlink(c *testing.T) { testRequires(c, DaemonIsLinux) result := cli.DockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "mkdir -p '"+cpTestPath+"' && echo -n '"+cpContainerContents+"' > "+cpFullPath+" && ln -s "+cpFullPath+" /dir_link") assert.Equal(c, result.ExitCode, 0, "failed to set up container: %s", result.Combined()) containerID := strings.TrimSpace(result.Stdout()) out := cli.DockerCmd(c, "wait", containerID).Combined() assert.Equal(c, strings.TrimSpace(out), "0", "failed to set up container") testDir, err := os.MkdirTemp("", "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. cli.DockerCmd(c, "cp", "-L", containerID+":"+"/dir_link", testDir) expectedPath := filepath.Join(testDir, "dir_link") expected := []byte(cpContainerContents) actual, err := os.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) } cli.DockerCmd(c, "cp", "-L", containerID+":"+"/dir_link", expectedPath) actual, err = os.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") }