tests: add "test/util" subpackage

Signed-off-by: Paulo Pires <pjpires@gmail.com>

test/util/resource_manager.go

@@ -0,0 +1,40 @@
+package util
+
+import (
+	"time"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/client-go/tools/cache"
+
+	"github.com/virtual-kubelet/virtual-kubelet/manager"
+)
+
+// FakeResourceManager returns an instance of the resource manager that will return the specified objects when its "GetX" methods are called.
+// Objects can be any valid Kubernetes object (corev1.Pod, corev1.ConfigMap, corev1.Secret, ...).
+func FakeResourceManager(objects ...runtime.Object) *manager.ResourceManager {
+	// Create a fake Kubernetes client that will list the specified objects.
+	kubeClient := fake.NewSimpleClientset(objects...)
+	// Create a shared informer factory from where we can grab informers and listers for pods, configmaps and secrets.
+	kubeInformerFactory := informers.NewSharedInformerFactory(kubeClient, 30*time.Second)
+	// Grab informers for pods, configmaps and secrets.
+	pInformer := kubeInformerFactory.Core().V1().Pods()
+	mInformer := kubeInformerFactory.Core().V1().ConfigMaps()
+	sInformer := kubeInformerFactory.Core().V1().Secrets()
+	// Start all the required informers.
+	go pInformer.Informer().Run(wait.NeverStop)
+	go mInformer.Informer().Run(wait.NeverStop)
+	go sInformer.Informer().Run(wait.NeverStop)
+	// Wait for the caches to be synced.
+	if !cache.WaitForCacheSync(wait.NeverStop, pInformer.Informer().HasSynced, mInformer.Informer().HasSynced, sInformer.Informer().HasSynced) {
+		panic("failed to wait for caches to be synced")
+	}
+	// Create a new instance of the resource manager using the listers for pods, configmaps and secrets.
+	r, err := manager.NewResourceManager(pInformer.Lister(), sInformer.Lister(), mInformer.Lister())
+	if err != nil {
+		panic(err)
+	}
+	return r
+}