remotes/docker: add scope (registry:foo/bar:pull)

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

remotes/docker/scope_test.go

@@ -0,0 +1,38 @@
+package docker
+
+import (
+	"testing"
+
+	"github.com/containerd/containerd/reference"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRepositoryScope(t *testing.T) {
+	testCases := []struct {
+		refspec  reference.Spec
+		push     bool
+		expected string
+	}{
+		{
+			refspec: reference.Spec{
+				Locator: "host/foo/bar",
+				Object:  "ignored",
+			},
+			push:     false,
+			expected: "repository:foo/bar:pull",
+		},
+		{
+			refspec: reference.Spec{
+				Locator: "host:4242/foo/bar",
+				Object:  "ignored",
+			},
+			push:     true,
+			expected: "repository:foo/bar:pull,push",
+		},
+	}
+	for _, x := range testCases {
+		actual, err := repositoryScope(x.refspec, x.push)
+		assert.NoError(t, err)
+		assert.Equal(t, x.expected, actual)
+	}
+}