move moby check to driver interface

Driver caching masked the method detection

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

driver/docker-container/driver.go

@@ -32,6 +32,10 @@ type Driver struct {
 	env     []string
 }
 
+func (d *Driver) IsMobyDriver() bool {
+	return false
+}
+
 func (d *Driver) Bootstrap(ctx context.Context, l progress.Logger) error {
 	return progress.Wrap("[internal] booting buildkit", l, func(sub progress.SubLogger) error {
 		_, err := d.DockerAPI.ContainerInspect(ctx, d.Name)

driver/docker/driver.go

@@ -57,4 +57,6 @@ func (d *Driver) Factory() driver.Factory {
 	return d.factory
 }
 
-func (d *Driver) IsDefaultMobyDriver() {}
+func (d *Driver) IsMobyDriver() bool {
+	return true
+}

driver/driver.go

@@ -57,6 +57,7 @@ type Driver interface {
 	Rm(ctx context.Context, force bool) error
 	Client(ctx context.Context) (*client.Client, error)
 	Features() map[Feature]bool
+	IsMobyDriver() bool
 }
 
 func Boot(ctx context.Context, d Driver, pw progress.Writer) (*client.Client, error) {

driver/kubernetes/driver.go

@@ -44,6 +44,10 @@ type Driver struct {
 	podChooser       podchooser.PodChooser
 }
 
+func (d *Driver) IsMobyDriver() bool {
+	return false
+}
+
 func (d *Driver) Bootstrap(ctx context.Context, l progress.Logger) error {
 	return progress.Wrap("[internal] booting buildkit", l, func(sub progress.SubLogger) error {
 		_, err := d.deploymentClient.Get(ctx, d.deployment.Name, metav1.GetOptions{})