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" // 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)

docs/reference/buildx_build.md

@@ -106,7 +106,7 @@ More built-in build args can be found in [dockerfile frontend docs](https://gith
 Define additional build context with specified contents. In Dockerfile the context can be accessed when `FROM name` or `--from=name` is used.
 When Dockerfile defines a stage with the same name it is overwritten.
 
-The value can be a local source directory, container image (with docker-image:// prefix), Git or HTTP URL.
+The value can be a local source directory, [local OCI layout compliant directory](https://github.com/opencontainers/image-spec/blob/main/image-layout.md), container image (with docker-image:// prefix), Git or HTTP URL.
 
 Replace `alpine:latest` with a pinned one:
 
@@ -126,6 +126,32 @@ FROM alpine
 COPY --from=project myfile /
 ```
 
+#### <a name="source-oci-layout"></a> Source image from OCI layout directory
+
+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

@@ -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/api v0.23.5
-	k8s.io/apimachinery v0.23.4
+	k8s.io/apimachinery v0.23.5
-	k8s.io/client-go v0.23.4
+	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
@@ -108,6 +109,7 @@ require (
 	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
@@ -135,6 +137,7 @@ require (
 	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

go.sum

@@ -419,8 +419,9 @@ github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.0/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -487,7 +488,6 @@ github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRW
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f/go.mod h1:ZdcZmHo+o7JKHSa8/e818NopupXU1YMK5fe1lsApnBw=
 github.com/ncw/swift v1.0.47/go.mod h1:23YIA4yWVnGwv2dQlN4bB7egfYX6YLn0Yo/S6zZO/ZM=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
@@ -516,6 +516,7 @@ github.com/pelletier/go-toml v1.9.3/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCko
 github.com/pelletier/go-toml v1.9.4 h1:tjENF6MfZAg8e4ZmZTeWaWiT2vXtsoO6+iuOjFhECwM=
 github.com/pelletier/go-toml v1.9.4/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
 github.com/peterbourgon/diskv v2.0.1+incompatible/go.mod h1:uqqh8zWWbv1HBMNONnaR/tNboyR3/BZd58JJSHlUSCU=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -558,6 +559,9 @@ github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6So
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-charset v0.0.0-20180617210344-2471d30d28b4/go.mod h1:qgYeAmZ5ZIpBWTGllZSQnw97Dj+woV0toclVaRGI8pc=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+github.com/rogpeppe/go-internal v1.8.1 h1:geMPLpDpQOgVyCg5z5GoRwLHepNdb71NXb67XFkP+Eg=
+github.com/rogpeppe/go-internal v1.8.1/go.mod h1:JeRgkft04UBgHMgCIwADu4Pn6Mtm5d4nPKWu0nJ5d+o=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
@@ -1095,8 +1099,9 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/check.v1 v1.0.0-20141024133853-64131543e789/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/dancannon/gorethink.v3 v3.0.5 h1:/g7PWP7zUS6vSNmHSDbjCHQh1Rqn8Jy6zSMQxAsBSMQ=
 gopkg.in/dancannon/gorethink.v3 v3.0.5/go.mod h1:GXsi1e3N2OcKhcP6nsYABTiUejbWMFO4GY5a4pEaeEc=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=

vendor/modules.txt

@@ -319,6 +319,8 @@ github.com/klauspost/compress/huff0
 github.com/klauspost/compress/internal/snapref
 github.com/klauspost/compress/zstd
 github.com/klauspost/compress/zstd/internal/xxhash
+# github.com/kr/pretty v0.3.0
+## explicit; go 1.12
 # github.com/mattn/go-shellwords v1.0.12
 ## explicit; go 1.13
 github.com/mattn/go-shellwords
@@ -461,6 +463,8 @@ github.com/prometheus/common/model
 github.com/prometheus/procfs
 github.com/prometheus/procfs/internal/fs
 github.com/prometheus/procfs/internal/util
+# github.com/rogpeppe/go-internal v1.8.1
+## explicit; go 1.16
 # github.com/serialx/hashring v0.0.0-20190422032157-8b2912629002
 ## explicit
 github.com/serialx/hashring
@@ -749,6 +753,8 @@ google.golang.org/protobuf/types/known/durationpb
 google.golang.org/protobuf/types/known/fieldmaskpb
 google.golang.org/protobuf/types/known/timestamppb
 google.golang.org/protobuf/types/known/wrapperspb
+# gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
+## explicit; go 1.11
 # gopkg.in/dancannon/gorethink.v3 v3.0.5
 ## explicit
 # gopkg.in/fatih/pool.v2 v2.0.0
@@ -764,7 +770,7 @@ gopkg.in/yaml.v2
 # gopkg.in/yaml.v3 v3.0.1
 ## explicit
 gopkg.in/yaml.v3
-# k8s.io/api v0.23.4 => k8s.io/api v0.22.4
+# k8s.io/api v0.23.5 => k8s.io/api v0.22.4
 ## explicit; go 1.16
 k8s.io/api/admissionregistration/v1
 k8s.io/api/admissionregistration/v1beta1
@@ -809,7 +815,7 @@ k8s.io/api/scheduling/v1beta1
 k8s.io/api/storage/v1
 k8s.io/api/storage/v1alpha1
 k8s.io/api/storage/v1beta1
-# k8s.io/apimachinery v0.23.4 => k8s.io/apimachinery v0.22.4
+# k8s.io/apimachinery v0.23.5 => k8s.io/apimachinery v0.22.4
 ## explicit; go 1.16
 k8s.io/apimachinery/pkg/api/errors
 k8s.io/apimachinery/pkg/api/meta
@@ -851,7 +857,7 @@ k8s.io/apimachinery/pkg/version
 k8s.io/apimachinery/pkg/watch
 k8s.io/apimachinery/third_party/forked/golang/netutil
 k8s.io/apimachinery/third_party/forked/golang/reflect
-# k8s.io/client-go v0.23.4 => k8s.io/client-go v0.22.4
+# k8s.io/client-go v0.23.5 => k8s.io/client-go v0.22.4
 ## explicit; go 1.16
 k8s.io/client-go/applyconfigurations/admissionregistration/v1
 k8s.io/client-go/applyconfigurations/admissionregistration/v1beta1