tests: introduce e2e suite (#422)

* mock: implement GetStatsSummary

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

* make: use skaffold to deploy vk

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

* test: add an e2e test suite

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

* test: add vendored code

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

* docs: update README.md

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

* ci: run e2e on circleci

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

* make: improve the skaffold target

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

* e2e: fix defer pod deletion

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

* e2e: improve instructions

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

* makefile: default shell is bash

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

test/e2e/framework/framework.go

@@ -0,0 +1,47 @@
+package framework
+
+import (
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+// Framework encapsulates the configuration for the current run, and provides helper methods to be used during testing.
+type Framework struct {
+	KubeClient  kubernetes.Interface
+	Namespace   string
+	NodeName    string
+	TaintKey    string
+	TaintValue  string
+	TaintEffect string
+}
+
+// NewTestingFramework returns a new instance of the testing framework.
+func NewTestingFramework(kubeconfig, namespace, nodeName, taintKey, taintValue, taintEffect string) *Framework {
+	return &Framework{
+		KubeClient:  createKubeClient(kubeconfig),
+		Namespace:   namespace,
+		NodeName:    nodeName,
+		TaintKey:    taintKey,
+		TaintValue:  taintValue,
+		TaintEffect: taintEffect,
+	}
+}
+
+// createKubeClient creates a new Kubernetes client based on the specified kubeconfig file.
+// If no value for kubeconfig is specified, in-cluster configuration is assumed.
+func createKubeClient(kubeconfig string) *kubernetes.Clientset {
+	var (
+		cfg *rest.Config
+		err error
+	)
+	if kubeconfig == "" {
+		cfg, err = rest.InClusterConfig()
+	} else {
+		cfg, err = clientcmd.BuildConfigFromFlags("", kubeconfig)
+	}
+	if err != nil {
+		panic(err)
+	}
+	return kubernetes.NewForConfigOrDie(cfg)
+}