add support for oci-layout build-context

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

build/build.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
+	_ "crypto/sha256"
 	"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"
@@ -1235,6 +1238,33 @@ 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://")
+			// need to add "dummy.io", because reference.Parse*() funcs require we do not start with a '/'
+			named, err := reference.ParseNormalizedNamed(fmt.Sprintf("dummy.io%s", pathAlone))
+			if err != nil {
+				return nil, errors.Wrapf(err, "invalid oci-layout context %s, must be oci-layout:///path/to/layout@sha256:hash", v.Path)
+			}
+			// check that we had a digest
+			digested, ok := named.(reference.Digested)
+			if !ok {
+				return nil, errors.Wrapf(err, "invalid oci-layout context %s, must be oci-layout:///path/to/layout@sha256:hash", v.Path)
+			}
+			// now ensure that we start with a `/`
+			localPath := fmt.Sprintf("/%s", reference.Path(named))
+			store, err := local.NewStore(localPath)
+			if err != nil {
+				return nil, errors.Wrapf(err, "invalid store at %s", localPath)
+			}
+			// now we can add it
+			target.OCIStores = map[string]content.Store{
+				k: store,
+			}
+			target.FrontendAttrs["context:"+k] = "oci-layout:" + k
+			continue
+		}
 		st, err := os.Stat(v.Path)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to get build context %v", k)

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
@@ -101,7 +101,7 @@ 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
@@ -128,7 +128,7 @@ 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/term v0.0.0-20210927222741-03fcf44c2211 // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac // indirect

go.sum

@@ -135,6 +135,8 @@ github.com/containerd/console v1.0.3 h1:lIr7SlA5PxZyMV30bDW0MGbiOPXwc63yRuCP0ARu
 github.com/containerd/console v1.0.3/go.mod h1:7LqA/THxQ86k76b8c/EMSiaJ3h1eZkMkXar0TQ1gf3U=
 github.com/containerd/containerd v1.6.4 h1:SEDZBp10mhCp+hkO3Njz/YhGrI7ah3edNcUlRdUPOgg=
 github.com/containerd/containerd v1.6.4/go.mod h1:oWOqbuJUZmOVafhA0lj2NAXbiO1u7F0K5l1bUgdyo94=
+github.com/containerd/containerd v1.6.6 h1:xJNPhbrmz8xAMDNoVjHy9YHtWwEQNS+CDkcIRh7t8Y0=
+github.com/containerd/containerd v1.6.6/go.mod h1:ZoP1geJldzCVY3Tonoz7b1IXk8rIX0Nltt5QE4OMNk0=
 github.com/containerd/continuity v0.1.0/go.mod h1:ICJu0PwR54nI0yPEnJ6jcS+J7CZAUXrLh8lPo2knzsM=
 github.com/containerd/continuity v0.3.0 h1:nisirsYROK15TAMVukJOUyGJjz4BNQJBVsNvAXZJ/eg=
 github.com/containerd/continuity v0.3.0/go.mod h1:wJEAIwKOm/pBZuBd0JmeTvnLquTB1Ag8espWhkykbPM=
@@ -459,6 +461,8 @@ github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RR
 github.com/mitchellh/osext v0.0.0-20151018003038-5e2d6d41470f/go.mod h1:OkQIRizQZAeMln+1tSwduZz7+Af5oFlKirV/MSYes2A=
 github.com/moby/buildkit v0.10.1-0.20220513101920-55f0ecfdafaa h1:Q8d1P3Ot+Z0eoynWkiWAfSyXRkvzPXqvUjE5y/Ycxw4=
 github.com/moby/buildkit v0.10.1-0.20220513101920-55f0ecfdafaa/go.mod h1:grddVHNUy3u8m1v5ZEbFKhpIwyGmLsSd8rRwJ5ccg7c=
+github.com/moby/buildkit v0.10.1-0.20220617010517-a6a114a1a476 h1:quXwiNE0nC/0bHFJkQKcwetpk1jNHIwwzDpq9hVmxSM=
+github.com/moby/buildkit v0.10.1-0.20220617010517-a6a114a1a476/go.mod h1:yle9eiU1fiJ/WhC4VTLOaQ6rxFou1mc4AhwScHwysi0=
 github.com/moby/locker v1.0.1 h1:fOXqR41zeveg4fFODix+1Ch4mj/gT0NE1XJbp/epuBg=
 github.com/moby/locker v1.0.1/go.mod h1:S7SDdo5zpBK84bzzVlKr2V0hz+7x9hWbYC/kq7oQppc=
 github.com/moby/spdystream v0.2.0 h1:cjW1zVyyoiM0T7b6UoySUFqzXMoqRckQtXwGPiBhOM8=
@@ -505,6 +509,8 @@ github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 h1:rc3
 github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
 github.com/opencontainers/runc v1.1.1 h1:PJ9DSs2sVwE0iVr++pAHE6QkS9tzcVWozlPifdwMgrU=
 github.com/opencontainers/runc v1.1.1/go.mod h1:Tj1hFw6eFWp/o33uxGf5yF2BX5yz2Z6iptFpuvbbKqc=
+github.com/opencontainers/runc v1.1.3 h1:vIXrkId+0/J2Ymu2m7VjGvbSlAId9XNRPhn2p4b+d8w=
+github.com/opencontainers/runc v1.1.3/go.mod h1:1J5XiS+vdZ3wCyZybsuxXZWGrgSr8fFJHLXuG2PsnNg=
 github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417 h1:3snG66yBm59tKhhSPQrQ/0bCrv1LQbKt40LnUPiUxdc=
 github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
 github.com/opencontainers/selinux v1.10.0/go.mod h1:2i0OySw99QjzBBQByd1Gr9gSjvuho1lHsJxIJ3gGbJI=
@@ -563,6 +569,7 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/seccomp/libseccomp-golang v0.9.2-0.20210429002308-3879420cc921/go.mod h1:JA8cRccbGaA1s33RQf7Y1+q9gHmZX1yB/z9WDN1C6fg=
+github.com/seccomp/libseccomp-golang v0.9.2-0.20220502022130-f33da4d89646/go.mod h1:JA8cRccbGaA1s33RQf7Y1+q9gHmZX1yB/z9WDN1C6fg=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/serialx/hashring v0.0.0-20190422032157-8b2912629002 h1:ka9QPuQg2u4LGipiZGsgkg3rJCo4iIUCy75FddM0GRQ=
@@ -893,6 +900,8 @@ golang.org/x/sys v0.0.0-20211116061358-0a5406a5449c/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220405210540-1e041c57c461 h1:kHVeDEnfKn3T238CvrUcz6KeEsFHVaKh4kMTt6Wsysg=
 golang.org/x/sys v0.0.0-20220405210540-1e041c57c461/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220412211240-33da011f77ad h1:ntjMns5wyP/fN65tdBD4g8J5w8n015+iIIs9rtjXkY0=
+golang.org/x/sys v0.0.0-20220412211240-33da011f77ad/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210220032956-6a3ed077a48d/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=