go.mod: change imports to github.com/distribution/distribution/v3

Go 1.13 and up enforce import paths to be versioned if a project
contains a go.mod and has released v2 or up.

The current v2.x branches (and releases) do not yet have a go.mod,
and therefore are still allowed to be imported with a non-versioned
import path (go modules add a `+incompatible` annotation in that case).

However, now that this project has a `go.mod` file, incompatible
import paths will not be accepted by go modules, and attempting
to use code from this repository will fail.

This patch uses `v3` for the import-paths (not `v2`), because changing
import paths itself is a breaking change, which means that  the
next release should increment the "major" version to comply with
SemVer (as go modules dictate).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

manifest/manifestlist/manifestlist.go

@@ -5,8 +5,8 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	"github.com/opencontainers/go-digest"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )

manifest/manifestlist/manifestlist_test.go

@@ -6,7 +6,7 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
+	"github.com/distribution/distribution/v3"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -119,7 +119,7 @@ func TestManifestList(t *testing.T) {
 // TODO (mikebrow): add annotations on the manifest list (index) and support for
 // empty platform structs (move to Platform *Platform `json:"platform,omitempty"`
 // from current Platform PlatformSpec `json:"platform"`) in the manifest descriptor.
-// Requires changes to docker/distribution/manifest/manifestlist.ManifestList and .ManifestDescriptor
+// Requires changes to distribution/distribution/manifest/manifestlist.ManifestList and .ManifestDescriptor
 // and associated serialization APIs in manifestlist.go. Or split the OCI index and
 // docker manifest list implementations, which would require a lot of refactoring.
 var expectedOCIImageIndexSerialization = []byte(`{

manifest/ocischema/builder.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"errors"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	"github.com/opencontainers/go-digest"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )

manifest/ocischema/builder_test.go

@@ -5,7 +5,7 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
+	"github.com/distribution/distribution/v3"
 	"github.com/opencontainers/go-digest"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )

manifest/ocischema/manifest.go

@@ -5,8 +5,8 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	"github.com/opencontainers/go-digest"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )

manifest/ocischema/manifest_test.go

@@ -6,8 +6,8 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 

manifest/schema1/config_builder.go

@@ -8,9 +8,9 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
-	"github.com/docker/distribution/reference"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
+	"github.com/distribution/distribution/v3/reference"
 	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 )

manifest/schema1/config_builder_test.go

@@ -8,9 +8,9 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
-	dcontext "github.com/docker/distribution/context"
-	"github.com/docker/distribution/reference"
+	"github.com/distribution/distribution/v3"
+	dcontext "github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/reference"
 	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 )

manifest/schema1/manifest.go

@@ -4,8 +4,8 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 )

manifest/schema1/reference_builder.go

@@ -5,9 +5,9 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
-	"github.com/docker/distribution/reference"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
+	"github.com/distribution/distribution/v3/reference"
 	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 )

manifest/schema1/reference_builder_test.go

@@ -3,9 +3,9 @@ package schema1
 import (
 	"testing"
 
-	"github.com/docker/distribution/context"
-	"github.com/docker/distribution/manifest"
-	"github.com/docker/distribution/reference"
+	"github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/manifest"
+	"github.com/distribution/distribution/v3/reference"
 	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 )

manifest/schema2/builder.go

@@ -3,7 +3,7 @@ package schema2
 import (
 	"context"
 
-	"github.com/docker/distribution"
+	"github.com/distribution/distribution/v3"
 	"github.com/opencontainers/go-digest"
 )
 

manifest/schema2/builder_test.go

@@ -5,7 +5,7 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
+	"github.com/distribution/distribution/v3"
 	"github.com/opencontainers/go-digest"
 )
 

manifest/schema2/manifest.go

@@ -5,8 +5,8 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 	"github.com/opencontainers/go-digest"
 )
 

manifest/schema2/manifest_test.go

@@ -6,8 +6,8 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/docker/distribution"
-	"github.com/docker/distribution/manifest"
+	"github.com/distribution/distribution/v3"
+	"github.com/distribution/distribution/v3/manifest"
 )
 
 var expectedManifestSerialization = []byte(`{