package build // import "github.com/docker/docker/integration/build" import ( "bufio" "bytes" "context" "io" "os" "strings" "testing" "github.com/docker/docker/api/types" "github.com/docker/docker/integration/internal/container" "github.com/docker/docker/pkg/jsonmessage" "github.com/docker/docker/pkg/stdcopy" "github.com/docker/docker/testutil/daemon" "github.com/docker/docker/testutil/fakecontext" "github.com/docker/docker/testutil/fixtures/load" "gotest.tools/v3/assert" "gotest.tools/v3/skip" ) // Implements a test for https://github.com/moby/moby/issues/41723 // Images built in a user-namespaced daemon should have capabilities serialised in // VFS_CAP_REVISION_2 (no user-namespace root uid) format rather than V3 (that includes // the root uid). func TestBuildUserNamespaceValidateCapabilitiesAreV2(t *testing.T) { skip.If(t, testEnv.DaemonInfo.OSType != "linux") skip.If(t, testEnv.IsRemoteDaemon()) skip.If(t, !testEnv.IsUserNamespaceInKernel()) skip.If(t, testEnv.IsRootless()) const imageTag = "capabilities:1.0" tmp, err := os.MkdirTemp("", "integration-") assert.NilError(t, err) defer os.RemoveAll(tmp) dUserRemap := daemon.New(t) dUserRemap.Start(t, "--userns-remap", "default") ctx := context.Background() clientUserRemap := dUserRemap.NewClientT(t) err = load.FrozenImagesLinux(clientUserRemap, "debian:bullseye-slim") assert.NilError(t, err) dUserRemapRunning := true defer func() { if dUserRemapRunning { dUserRemap.Stop(t) } }() dockerfile := ` FROM debian:bullseye-slim RUN apt-get update && apt-get install -y libcap2-bin --no-install-recommends RUN setcap CAP_NET_BIND_SERVICE=+eip /bin/sleep ` source := fakecontext.New(t, "", fakecontext.WithDockerfile(dockerfile)) defer source.Close() resp, err := clientUserRemap.ImageBuild(ctx, source.AsTarReader(t), types.ImageBuildOptions{ Tags: []string{imageTag}, }) assert.NilError(t, err) defer resp.Body.Close() buf := bytes.NewBuffer(nil) err = jsonmessage.DisplayJSONMessagesStream(resp.Body, buf, 0, false, nil) assert.NilError(t, err) reader, err := clientUserRemap.ImageSave(ctx, []string{imageTag}) assert.NilError(t, err, "failed to download capabilities image") defer reader.Close() tar, err := os.Create(tmp + "/image.tar") assert.NilError(t, err, "failed to create image tar file") defer tar.Close() _, err = io.Copy(tar, reader) assert.NilError(t, err, "failed to write image tar file") dUserRemap.Stop(t) dUserRemap.Cleanup(t) dUserRemapRunning = false dNoUserRemap := daemon.New(t) dNoUserRemap.Start(t) defer dNoUserRemap.Stop(t) clientNoUserRemap := dNoUserRemap.NewClientT(t) tarFile, err := os.Open(tmp + "/image.tar") assert.NilError(t, err, "failed to open image tar file") tarReader := bufio.NewReader(tarFile) loadResp, err := clientNoUserRemap.ImageLoad(ctx, tarReader, false) assert.NilError(t, err, "failed to load image tar file") defer loadResp.Body.Close() buf = bytes.NewBuffer(nil) err = jsonmessage.DisplayJSONMessagesStream(loadResp.Body, buf, 0, false, nil) assert.NilError(t, err) cid := container.Run(ctx, t, clientNoUserRemap, container.WithImage(imageTag), container.WithCmd("/sbin/getcap", "-n", "/bin/sleep"), ) logReader, err := clientNoUserRemap.ContainerLogs(ctx, cid, types.ContainerLogsOptions{ ShowStdout: true, }) assert.NilError(t, err) actualStdout := new(bytes.Buffer) actualStderr := io.Discard _, err = stdcopy.StdCopy(actualStdout, actualStderr, logReader) assert.NilError(t, err) if strings.TrimSpace(actualStdout.String()) != "/bin/sleep cap_net_bind_service=eip" { t.Fatalf("run produced invalid output: %q, expected %q", actualStdout.String(), "/bin/sleep cap_net_bind_service=eip") } }