test(promClientController): unit test the implementation

Author: ingvagabund

pkg/descheduler/descheduler.go

@@ -91,20 +91,24 @@ type descheduler struct {
 	promClientCtrl        *promClientController
 }
 
+type createPrometheusClientFunc func(url, token string) (promapi.Client, *http.Transport, error)
+
 type promClientController struct {
 	promClient                        promapi.Client
 	previousPrometheusClientTransport *http.Transport
 	queue                             workqueue.RateLimitingInterface
 	currentPrometheusAuthToken        string
 	namespacedSecretsLister           corev1listers.SecretNamespaceLister
 	metricsProviders                  map[api.MetricsSource]*api.MetricsProvider
+	createPrometheusClient            createPrometheusClientFunc
 }
 
 func newPromClientController(prometheusClient promapi.Client, metricsProviders map[api.MetricsSource]*api.MetricsProvider) *promClientController {
 	return &promClientController{
-		promClient:       prometheusClient,
-		queue:            workqueue.NewRateLimitingQueueWithConfig(workqueue.DefaultControllerRateLimiter(), workqueue.RateLimitingQueueConfig{Name: "descheduler"}),
-		metricsProviders: metricsProviders,
+		promClient:             prometheusClient,
+		queue:                  workqueue.NewRateLimitingQueueWithConfig(workqueue.DefaultControllerRateLimiter(), workqueue.RateLimitingQueueConfig{Name: "descheduler"}),
+		metricsProviders:       metricsProviders,
+		createPrometheusClient: client.CreatePrometheusClient,
 	}
 }
 
@@ -221,7 +225,7 @@ func (d *promClientController) reconcileInClusterSAToken() error {
 	if err == nil {
 		if d.currentPrometheusAuthToken != cfg.BearerToken {
 			klog.V(2).Infof("Creating Prometheus client (with SA token)")
-			prometheusClient, transport, err := client.CreatePrometheusClient(d.metricsProviders[api.PrometheusMetrics].Prometheus.URL, cfg.BearerToken)
+			prometheusClient, transport, err := d.createPrometheusClient(d.metricsProviders[api.PrometheusMetrics].Prometheus.URL, cfg.BearerToken)
 			if err != nil {
 				return fmt.Errorf("unable to create a prometheus client: %v", err)
 			}
@@ -305,7 +309,7 @@ func (d *promClientController) sync() error {
 	}
 
 	klog.V(2).Infof("authentication secret token updated, recreating prometheus client")
-	prometheusClient, transport, err := client.CreatePrometheusClient(prometheusConfig.URL, authToken)
+	prometheusClient, transport, err := d.createPrometheusClient(prometheusConfig.URL, authToken)
 	if err != nil {
 		return fmt.Errorf("unable to create a prometheus client: %v", err)
 	}