add alpha version

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

pkg/cri/server/version.go

@@ -20,6 +20,7 @@ import (
 	"github.com/containerd/containerd/version"
 	"golang.org/x/net/context"
 	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"
+	runtime_alpha "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
 
 	"github.com/containerd/containerd/pkg/cri/constants"
 )
@@ -40,3 +41,13 @@ func (c *criService) Version(ctx context.Context, r *runtime.VersionRequest) (*r
 		RuntimeApiVersion: constants.CRIVersion,
 	}, nil
 }
+
+// Version returns the runtime name, runtime version and runtime API version.
+func (c *criService) AlphaVersion(ctx context.Context, r *runtime_alpha.VersionRequest) (*runtime_alpha.VersionResponse, error) {
+	return &runtime_alpha.VersionResponse{
+		Version:           kubeAPIVersion,
+		RuntimeName:       containerName,
+		RuntimeVersion:    version.Version,
+		RuntimeApiVersion: constants.CRIVersionAlpha,
+	}, nil
+}