Add builder OCI layout build context

Signed-off-by: Austin Vazquez <[email protected]>

cmd/nerdctl/builder_build_linux_test.go

@@ -0,0 +1,80 @@
+/*
+ Copyright The containerd Authors.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+package main
+
+import (
+ "fmt"
+ "testing"
+
+ "github.com/containerd/nerdctl/v2/pkg/testutil"
+ "gotest.tools/v3/assert"
+)
+
+func TestBuildContextWithOCILayout(t *testing.T) {
+ testutil.RequiresBuild(t)
+ testutil.RegisterBuildCacheCleanup(t)
+
+ var dockerBuilderArgs []string
+ if testutil.IsDocker() {
+ // Default docker driver does not support OCI exporter.
+ // Reference: https://docs.docker.com/build/exporters/oci-docker/
+ builderName := testutil.SetupDockerContainerBuilder(t)
+ dockerBuilderArgs = []string{"buildx", "--builder", builderName}
+ }
+
+ base := testutil.NewBase(t)
+ imageName := testutil.Identifier(t)
+ t.Cleanup(func() { base.Cmd("rmi", imageName) })
+
+ dockerfile := fmt.Sprintf(`FROM %s
+LABEL layer=oci-layout-parent
+CMD ["echo", "test-nerdctl-build-context-oci-layout-parent"]`, testutil.CommonImage)
+ buildCtx := createBuildContext(t, dockerfile)
+
+ tarPath := fmt.Sprintf("%s/%s", buildCtx, "test.tar")
+
+ var buildArgs []string
+ if testutil.IsDocker() {
+ buildArgs = dockerBuilderArgs
+ }
+
+ buildArgs = append(buildArgs, "build", fmt.Sprintf("--output=type=oci,dest=%s", tarPath))
+ base.Cmd(buildArgs...).Run()
+
+ ociLayoutDir := t.TempDir()
+ err := extractTarFile(ociLayoutDir, tarPath)
+ assert.NilError(t, err)
+
+ ociLayout := "parent"
+ dockerfile = fmt.Sprintf(`FROM %s
+CMD ["echo", "test-nerdctl-build-context-oci-layout"]`, ociLayout)
+ buildCtx = createBuildContext(t, dockerfile)
+
+ buildArgs = []string{}
+ if testutil.IsDocker() {
+ buildArgs = dockerBuilderArgs
+ }
+
+ buildArgs = append(buildArgs, "build", buildCtx, fmt.Sprintf("--build-context=%s=oci-layout://%s", ociLayout, ociLayoutDir))
+ if testutil.IsDocker() {
+ // Need to load the container image from the builder to be able to run it.
+ buildArgs = append(buildArgs, "--load")
+ }
+
+ base.Cmd(buildArgs...).Run()
+ base.Cmd("run", "--rm", imageName).AssertOutContains("test-nerdctl-build-context-oci-layout")
+}

docs/command-reference.md

@@ -708,7 +708,7 @@ Flags:
 - :nerd_face: `--ipfs`: Build image with pulling base images from IPFS. See [`ipfs.md`](./ipfs.md) for details.
 - :whale: `--label`: Set metadata for an image
 - :whale: `--network=(default|host|none)`: Set the networking mode for the RUN instructions during build.(compatible with `buildctl build`)
-- :whale: --build-context: Set additional contexts for build (e.g. dir2=/path/to/dir2, myorg/myapp=docker-image://path/to/myorg/myapp)
+- :whale: `--build-context`: Set additional contexts for build (e.g. dir2=/path/to/dir2, myorg/myapp=docker-image://path/to/myorg/myapp)
 
 Unimplemented `docker build` flags: `--add-host`, `--squash`
 

pkg/cmd/builder/build.go

@@ -36,6 +36,7 @@ import (
  "github.com/containerd/errdefs"
  "github.com/containerd/log"
  "github.com/containerd/platforms"
+ ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 
  "github.com/containerd/nerdctl/v2/pkg/api/types"
  "github.com/containerd/nerdctl/v2/pkg/buildkitutil"
@@ -300,6 +301,16 @@ func generateBuildctlArgs(ctx context.Context, client *containerd.Client, option
  continue
  }
 
+ if isOCILayout := strings.HasPrefix(v, "oci-layout://"); isOCILayout {
+ args, err := parseBuildContextFromOCILayout(k, v)
+ if err != nil {
+ return "", nil, false, "", nil, nil, err
+ }
+
+ buildctlArgs = append(buildctlArgs, args...)
+ continue
+ }
+
  path, err := filepath.Abs(v)
  if err != nil {
  return "", nil, false, "", nil, nil, err
@@ -534,3 +545,61 @@ func parseContextNames(values []string) (map[string]string, error) {
  }
  return result, nil
 }
+
+var (
+ errOCILayoutPrefixNotFound = errors.New("OCI layout prefix not found")
+ errOCILayoutEmptyDigest = errors.New("OCI layout cannot have empty digest")
+)
+
+func parseBuildContextFromOCILayout(name, path string) ([]string, error) {
+ path, found := strings.CutPrefix(path, "oci-layout://")
+ if !found {
+ return []string{}, errOCILayoutPrefixNotFound
+ }
+
+ abspath, err := filepath.Abs(path)
+ if err != nil {
+ return []string{}, err
+ }
+
+ ociIndex, err := readOCIIndexFromPath(abspath)
+ if err != nil {
+ return []string{}, err
+ }
+
+ var digest string
+ for _, manifest := range ociIndex.Manifests {
+ if manifest.MediaType == ocispec.MediaTypeImageManifest {
+ digest = manifest.Digest.String()
+ }
+ }
+
+ if digest == "" {
+ return []string{}, errOCILayoutEmptyDigest
+ }
+
+ return []string{
+ fmt.Sprintf("--oci-layout=parent-image-key=%s", abspath),
+ fmt.Sprintf("--opt=context:%s=oci-layout:parent-image-key@%s", name, digest),
+ }, nil
+}
+
+func readOCIIndexFromPath(path string) (*ocispec.Index, error) {
+ ociIndexJSONFile, err := os.Open(path + "/index.json")
+ if err != nil {
+ return nil, err
+ }
+ defer ociIndexJSONFile.Close()
+
+ rawBytes, err := io.ReadAll(ociIndexJSONFile)
+ if err != nil {
+ return nil, err
+ }
+
+ var ociIndex *ocispec.Index
+ err = json.Unmarshal(rawBytes, &ociIndex)
+ if err != nil {
+ return nil, err
+ }
+ return ociIndex, nil
+}

pkg/cmd/builder/build_test.go

@@ -187,3 +187,42 @@ func TestIsBuildPlatformDefault(t *testing.T) {
  })
  }
 }
+
+func TestParseBuildctlArgsForOCILayout(t *testing.T) {
+ tests := []struct {
+ name string
+ ociLayoutName string
+ ociLayoutPath string
+ expectedArgs []string
+ errorIsNil bool
+ expectedErr string
+ }{
+ {
+ name: "PrefixNotFoundError",
+ ociLayoutName: "unit-test",
+ ociLayoutPath: "/tmp/oci-layout/",
+ expectedArgs: []string{},
+ expectedErr: "OCI layout prefix not found",
+ },
+ {
+ name: "DirectoryNotFoundError",
+ ociLayoutName: "unit-test",
+ ociLayoutPath: "oci-layout:///tmp/oci-layout",
+ expectedArgs: []string{},
+ expectedErr: "open /tmp/oci-layout/index.json: no such file or directory",
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ args, err := parseBuildContextFromOCILayout(test.ociLayoutName, test.ociLayoutPath)
+ if test.errorIsNil {
+ assert.NilError(t, err)
+ } else {
+ assert.Error(t, err, test.expectedErr)
+ }
+ assert.Equal(t, len(args), len(test.expectedArgs))
+ assert.DeepEqual(t, args, test.expectedArgs)
+ })
+ }
+}

pkg/testutil/testutil.go

@@ -574,8 +574,12 @@ func GetDaemonIsKillable() bool {
  return flagTestKillDaemon
 }
 
+func IsDocker() bool {
+ return GetTarget() == Docker
+}
+
 func DockerIncompatible(t testing.TB) {
- if GetTarget() == Docker {
+ if IsDocker() {
  t.Skip("test is incompatible with Docker")
  }
 }
@@ -788,3 +792,14 @@ func KubectlHelper(base *Base, args ...string) *Cmd {
  Base: base,
  }
 }
+
+func SetupDockerContainerBuilder(t *testing.T) string {
+ name := fmt.Sprintf("%s-container", Identifier(t))
+ base := NewBase(t)
+ base.Cmd("buildx", "create", "--name", name, "--driver=docker-container").AssertOK()
+ t.Cleanup(func() {
+ base.Cmd("buildx", "stop", name).AssertOK()
+ base.Cmd("buildx", "rm", "--force", name).AssertOK()
+ })
+ return name
+}