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>

registry/auth/htpasswd/access.go

@@ -18,8 +18,8 @@ import (
 
 	"golang.org/x/crypto/bcrypt"
 
-	dcontext "github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	dcontext "github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 )
 
 type accessController struct {

registry/auth/htpasswd/access_test.go

@@ -8,8 +8,8 @@ import (
 	"os"
 	"testing"
 
-	"github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	"github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 )
 
 func TestBasicAccessController(t *testing.T) {

registry/auth/htpasswd/htpasswd.go

@@ -6,7 +6,7 @@ import (
 	"io"
 	"strings"
 
-	"github.com/docker/distribution/registry/auth"
+	"github.com/distribution/distribution/v3/registry/auth"
 
 	"golang.org/x/crypto/bcrypt"
 )

registry/auth/silly/access.go

@@ -13,8 +13,8 @@ import (
 	"net/http"
 	"strings"
 
-	dcontext "github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	dcontext "github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 )
 
 // accessController provides a simple implementation of auth.AccessController

registry/auth/silly/access_test.go

@@ -5,8 +5,8 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	"github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	"github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 )
 
 func TestSillyAccessController(t *testing.T) {

registry/auth/token/accesscontroller.go

@@ -12,8 +12,8 @@ import (
 	"os"
 	"strings"
 
-	dcontext "github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	dcontext "github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 	"github.com/docker/libtrust"
 )
 

registry/auth/token/token.go

@@ -13,7 +13,7 @@ import (
 	"github.com/docker/libtrust"
 	log "github.com/sirupsen/logrus"
 
-	"github.com/docker/distribution/registry/auth"
+	"github.com/distribution/distribution/v3/registry/auth"
 )
 
 const (

registry/auth/token/token_test.go

@@ -15,8 +15,8 @@ import (
 	"testing"
 	"time"
 
-	"github.com/docker/distribution/context"
-	"github.com/docker/distribution/registry/auth"
+	"github.com/distribution/distribution/v3/context"
+	"github.com/distribution/distribution/v3/registry/auth"
 	"github.com/docker/libtrust"
 )