1. update clientset, deepcopy using code-generator

2. add a dummy file tools.go to force "go mod vendor" to see
code-generator as dependencies
3. add a script to update CRD
4. add a README to document CRD updating steps
run go mod tidy
update README

pkg/client/clientset/versioned/clientset.go

@@ -19,6 +19,8 @@ limitations under the License.
 package versioned
 
 import (
+	"fmt"
+
 	snapshotv1beta1 "github.com/kubernetes-csi/external-snapshotter/pkg/client/clientset/versioned/typed/volumesnapshot/v1beta1"
 	discovery "k8s.io/client-go/discovery"
 	rest "k8s.io/client-go/rest"
@@ -51,9 +53,14 @@ func (c *Clientset) Discovery() discovery.DiscoveryInterface {
 }
 
 // NewForConfig creates a new Clientset for the given config.
+// If config's RateLimiter is not set and QPS and Burst are acceptable,
+// NewForConfig will generate a rate-limiter in configShallowCopy.
 func NewForConfig(c *rest.Config) (*Clientset, error) {
 	configShallowCopy := *c
 	if configShallowCopy.RateLimiter == nil && configShallowCopy.QPS > 0 {
+		if configShallowCopy.Burst <= 0 {
+			return nil, fmt.Errorf("Burst is required to be greater than 0 when RateLimiter is not set and QPS is set to greater than 0")
+		}
 		configShallowCopy.RateLimiter = flowcontrol.NewTokenBucketRateLimiter(configShallowCopy.QPS, configShallowCopy.Burst)
 	}
 	var cs Clientset