add support for oci-layout build-context

Signed-off-by: Avi Deitcher <avi@deitcher.net>

bake/bake.go

@@ -17,6 +17,7 @@ import (
 	"github.com/docker/buildx/build"
 	"github.com/docker/buildx/util/buildflags"
 	"github.com/docker/buildx/util/platformutil"
+	"github.com/docker/cli/cli/config"
 	"github.com/docker/docker/pkg/urlutil"
 	hcl "github.com/hashicorp/hcl/v2"
 	"github.com/moby/buildkit/client/llb"
@@ -882,7 +883,7 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 	}
 	bo.Platforms = platforms
 
-	bo.Session = append(bo.Session, authprovider.NewDockerAuthProvider(os.Stderr))
+	bo.Session = append(bo.Session, authprovider.NewDockerAuthProvider(config.LoadDefaultConfigFile(os.Stderr)))
 
 	secrets, err := buildflags.ParseSecretSpecs(t.Secrets)
 	if err != nil {

build/build.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
+	_ "crypto/sha256" // ensure digests can be computed
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -17,6 +18,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/content/local"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/platforms"
 	"github.com/docker/buildx/driver"
@@ -1333,6 +1336,32 @@ func LoadInputs(ctx context.Context, d driver.Driver, inp Inputs, pw progress.Wr
 			target.FrontendAttrs["context:"+k] = v.Path
 			continue
 		}
+
+		// handle OCI layout
+		if strings.HasPrefix(v.Path, "oci-layout://") {
+			pathAlone := strings.TrimPrefix(v.Path, "oci-layout://")
+			parts := strings.SplitN(pathAlone, "@", 2)
+			if len(parts) != 2 {
+				return nil, errors.Errorf("invalid oci-layout context %s, must be oci-layout:///path/to/layout@sha256:hash", v.Path)
+			}
+			localPath := parts[0]
+			dgst, err := digest.Parse(parts[1])
+			if err != nil {
+				return nil, errors.Wrapf(err, "invalid oci-layout context %s, does not have proper hash, must be oci-layout:///path/to/layout@sha256:hash", v.Path)
+			}
+			store, err := local.NewStore(localPath)
+			if err != nil {
+				return nil, errors.Wrapf(err, "invalid store at %s", localPath)
+			}
+			// now we can add it
+			if target.OCIStores == nil {
+				target.OCIStores = map[string]content.Store{}
+			}
+			target.OCIStores[k] = store
+
+			target.FrontendAttrs["context:"+k] = fmt.Sprintf("oci-layout:%s@%s", k, dgst.String())
+			continue
+		}
 		st, err := os.Stat(v.Path)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to get build context %v", k)

commands/build.go

@@ -25,6 +25,7 @@ import (
 	"github.com/docker/cli-docs-tool/annotation"
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/cli/config"
 	dockeropts "github.com/docker/cli/opts"
 	"github.com/docker/distribution/reference"
 	"github.com/docker/docker/pkg/ioutils"
@@ -148,7 +149,7 @@ func runBuild(dockerCli command.Cli, in buildOptions) (err error) {
 	}
 	opts.Platforms = platforms
 
-	opts.Session = append(opts.Session, authprovider.NewDockerAuthProvider(os.Stderr))
+	opts.Session = append(opts.Session, authprovider.NewDockerAuthProvider(config.LoadDefaultConfigFile(os.Stderr)))
 
 	secrets, err := buildflags.ParseSecretSpecs(in.secrets)
 	if err != nil {

docs/reference/buildx_build.md

@@ -126,6 +126,30 @@ FROM alpine
 COPY --from=project myfile /
 ```
 
+Source an image from a local [OCI layout compliant directory](https://github.com/opencontainers/image-spec/blob/main/image-layout.md):
+
+```console
+$ docker buildx build --build-context foo=oci-layout:///path/to/local/layout@sha256:abcd12345 .
+```
+
+```Dockerfile
+FROM alpine
+RUN apk add git
+
+COPY --from=foo myfile /
+
+FROM foo
+```
+
+The OCI layout directory must be compliant with the [OCI layout specification](https://github.com/opencontainers/image-spec/blob/main/image-layout.md). It looks _solely_ for hashes. It does not
+do any form of `image:tag` resolution to find the hash of the manifest; that is up to you.
+
+The format of the `--build-context` must be: `<context>=oci-layout://<path-to-local-layout>@sha256:<hash-of-manifest>`, where:
+
+* `context` is the name of the build context as used in the `Dockerfile`.
+* `path-to-local-layout` is the path on the local machine, where you are running `docker build`, to the spec-compliant OCI layout.
+* `hash-of-manifest` is the hash of the manifest for the image. It can be a single-architecture manifest or a multi-architecture index.
+
 ### <a name="builder"></a> Override the configured builder instance (--builder)
 
 Same as [`buildx --builder`](buildx.md#builder).

go.mod

@@ -5,7 +5,7 @@ go 1.17
 require (
 	github.com/compose-spec/compose-go v1.2.7
 	github.com/containerd/console v1.0.3
-	github.com/containerd/containerd v1.6.4
+	github.com/containerd/containerd v1.6.6
 	github.com/docker/cli v20.10.14+incompatible
 	github.com/docker/cli-docs-tool v0.4.0
 	github.com/docker/distribution v2.8.1+incompatible
@@ -15,7 +15,7 @@ require (
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/hashicorp/go-cty-funcs v0.0.0-20200930094925-2721b1e36840
 	github.com/hashicorp/hcl/v2 v2.8.2
-	github.com/moby/buildkit v0.10.1-0.20220513101920-55f0ecfdafaa
+	github.com/moby/buildkit v0.10.1-0.20220617010517-a6a114a1a476
 	github.com/morikuni/aec v1.0.0
 	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799
@@ -33,9 +33,9 @@ require (
 	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211
 	google.golang.org/grpc v1.45.0
 	gopkg.in/yaml.v3 v3.0.1
-	k8s.io/api v0.23.4
-	k8s.io/apimachinery v0.23.4
-	k8s.io/client-go v0.23.4
+	k8s.io/api v0.23.5
+	k8s.io/apimachinery v0.23.5
+	k8s.io/client-go v0.23.5
 )
 
 require (
@@ -89,6 +89,7 @@ require (
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 // indirect
 	github.com/klauspost/compress v1.15.1 // indirect
+	github.com/kr/pretty v0.3.0 // indirect
 	github.com/mattn/go-shellwords v1.0.12 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
 	github.com/miekg/pkcs11 v1.1.1 // indirect
@@ -102,12 +103,13 @@ require (
 	github.com/moby/term v0.0.0-20210619224110-3f7ff695adc6 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
-	github.com/opencontainers/runc v1.1.1 // indirect
+	github.com/opencontainers/runc v1.1.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_golang v1.12.1 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
 	github.com/prometheus/common v0.32.1 // indirect
 	github.com/prometheus/procfs v0.7.3 // indirect
+	github.com/rogpeppe/go-internal v1.8.1 // indirect
 	github.com/theupdateframework/notary v0.6.1 // indirect
 	github.com/tonistiigi/fsutil v0.0.0-20220510150904-0dbf3a8a7d58 // indirect
 	github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea // indirect
@@ -129,12 +131,13 @@ require (
 	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd // indirect
 	golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd // indirect
 	golang.org/x/oauth2 v0.0.0-20210819190943-2bc19b11175f // indirect
-	golang.org/x/sys v0.0.0-20220405210540-1e041c57c461 // indirect
+	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac // indirect
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/genproto v0.0.0-20220107163113-42d7afdf6368 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/dancannon/gorethink.v3 v3.0.5 // indirect
 	gopkg.in/fatih/pool.v2 v2.0.0 // indirect
 	gopkg.in/gorethink/gorethink.v3 v3.0.5 // indirect