Add support for modifying the created Factory clients (#602)

Add support for modifying the created Factory clients

This adds a new functional-opt based mechanism for configuring the factory clients, and provides a new function for allowing consumers to provide the QPS and Burst values for configuring clients.

pkg/client/factory.go

@@ -15,6 +15,13 @@ import (
 	"k8s.io/client-go/rest"
 )
 
+const (
+	// defaultQPS and defaultBurst are used to configure the rest.Config for
+	// factory created clients.
+	defaultQPS   float32 = 10000
+	defaultBurst int     = 100
+)
+
 type Factory struct {
 	impersonate         bool
 	tableClientCfg      *rest.Config
@@ -47,10 +54,41 @@ func (a *addQuery) WrappedRoundTripper() http.RoundTripper {
 	return a.next
 }
 
-func NewFactory(cfg *rest.Config, impersonate bool) (*Factory, error) {
+type factoryOptions struct {
+	qps   float32
+	burst int
+}
+
+func defaultFactoryOptions() *factoryOptions {
+	return &factoryOptions{
+		qps:   defaultQPS,
+		burst: defaultBurst,
+	}
+}
+
+// WithQPSAndBurst configures the rest.Config used for creating the clients in
+// the factory with the provided burst and qps configuration.
+//
+// See https://pkg.go.dev/k8s.io/client-go/rest#Config for more.
+func WithQPSAndBurst(qps float32, burst int) FactoryOption {
+	return func(opts *factoryOptions) {
+		opts.qps = qps
+		opts.burst = burst
+	}
+}
+
+// FactoryOption is an option-func for configuring the newly created factory.
+type FactoryOption func(*factoryOptions)
+
+func NewFactory(cfg *rest.Config, impersonate bool, opts ...FactoryOption) (*Factory, error) {
 	clientCfg := rest.CopyConfig(cfg)
-	clientCfg.QPS = 10000
-	clientCfg.Burst = 100
+	options := defaultFactoryOptions()
+	for _, opt := range opts {
+		opt(options)
+	}
+
+	clientCfg.QPS = options.qps
+	clientCfg.Burst = options.burst
 
 	watchClientCfg := rest.CopyConfig(clientCfg)
 	watchClientCfg.Timeout = 30 * time.Minute

pkg/client/factory_test.go

@@ -0,0 +1,32 @@
+package client
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"k8s.io/client-go/rest"
+)
+
+func TestWithQPSAndBurst(t *testing.T) {
+	fo := defaultFactoryOptions()
+
+	assert.Equal(t, defaultQPS, fo.qps)
+	assert.Equal(t, defaultBurst, fo.burst)
+
+	WithQPSAndBurst(50, 20)(fo)
+
+	assert.Equal(t, float32(50.0), fo.qps)
+	assert.Equal(t, 20, fo.burst)
+}
+
+func TestNewFactoryWithOptions(t *testing.T) {
+	cfg := &rest.Config{
+		QPS:   5.0,
+		Burst: 10,
+	}
+	f, err := NewFactory(cfg, false, WithQPSAndBurst(50, 20))
+	assert.NoError(t, err)
+
+	assert.Equal(t, float32(50.0), f.clientCfg.QPS)
+	assert.Equal(t, 20, f.clientCfg.Burst)
+}