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/basic_test.go

@@ -0,0 +1,144 @@
+// +build e2e
+
+package e2e
+
+import (
+	"fmt"
+	"testing"
+
+	"k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+)
+
+// TestGetStatsSummary creates a pod having two containers and queries the /stats/summary endpoint of the virtual-kubelet.
+// It expects this endpoint to return stats for the current node, as well as for the aforementioned pod and each of its two containers.
+func TestGetStatsSummary(t *testing.T) {
+	// Create a pod with prefix "nginx-0-" having three containers.
+	pod, err := f.CreatePod(f.CreateDummyPodObjectWithPrefix("nginx-0-", "foo", "bar", "baz"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Delete the "nginx-0-X" pod after the test finishes.
+	defer func() {
+		if err := f.DeletePod(pod.Namespace, pod.Name); err != nil && !apierrors.IsNotFound(err) {
+			t.Error(err)
+		}
+	}()
+
+	// Wait for the "nginx-0-X" pod to be reported as running and ready.
+	if err := f.WaitUntilPodReady(pod.Namespace, pod.Name); err != nil {
+		t.Fatal(err)
+	}
+
+	// Grab the stats from the provider.
+	stats, err := f.GetStatsSummary()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Make sure that we've got stats for the current node.
+	if stats.Node.NodeName != f.NodeName {
+		t.Fatalf("expected stats for node %s, got stats for node %s", f.NodeName, stats.Node.NodeName)
+	}
+
+	// Make sure the "nginx-0-X" pod exists in the slice of PodStats.
+	idx, err := findPodInPodStats(stats, pod)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Make sure that we've got stats for all the containers in the "nginx-0-X" pod.
+	desiredContainerStatsCount := len(pod.Spec.Containers)
+	currentContainerStatsCount := len(stats.Pods[idx].Containers)
+	if currentContainerStatsCount != desiredContainerStatsCount {
+		t.Fatalf("expected stats for %d containers, got stats for %d containers", desiredContainerStatsCount, currentContainerStatsCount)
+	}
+}
+
+// TestPodLifecycle creates two pods and verifies that the provider has been asked to create them.
+// Then, it deletes one of the pods and verifies that the provider has been asked to delete it.
+// These verifications are made using the /stats/summary endpoint of the virtual-kubelet, by checking for the presence or absence of the pods.
+// Hence, the provider being tested must implement the PodMetricsProvider interface.
+func TestPodLifecycle(t *testing.T) {
+	// Create a pod with prefix "nginx-0-" having a single container.
+	pod0, err := f.CreatePod(f.CreateDummyPodObjectWithPrefix("nginx-0-", "foo"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Delete the "nginx-0-X" pod after the test finishes.
+	defer func() {
+		if err := f.DeletePod(pod0.Namespace, pod0.Name); err != nil && !apierrors.IsNotFound(err) {
+			t.Error(err)
+		}
+	}()
+
+	// Create a pod with prefix "nginx-1-" having a single container.
+	pod1, err := f.CreatePod(f.CreateDummyPodObjectWithPrefix("nginx-1-", "bar"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Delete the "nginx-1-Y" pod after the test finishes.
+	defer func() {
+		if err := f.DeletePod(pod1.Namespace, pod1.Name); err != nil && !apierrors.IsNotFound(err) {
+			t.Error(err)
+		}
+	}()
+
+	// Wait for the "nginx-0-X" pod to be reported as running and ready.
+	if err := f.WaitUntilPodReady(pod0.Namespace, pod0.Name); err != nil {
+		t.Fatal(err)
+	}
+	// Wait for the "nginx-1-Y" pod to be reported as running and ready.
+	if err := f.WaitUntilPodReady(pod1.Namespace, pod1.Name); err != nil {
+		t.Fatal(err)
+	}
+
+	// Grab the stats from the provider.
+	stats, err := f.GetStatsSummary()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Make sure the "nginx-0-X" pod exists in the slice of PodStats.
+	if _, err := findPodInPodStats(stats, pod0); err != nil {
+		t.Fatal(err)
+	}
+
+	// Make sure the "nginx-1-Y" pod exists in the slice of PodStats.
+	if _, err := findPodInPodStats(stats, pod1); err != nil {
+		t.Fatal(err)
+	}
+
+	// Delete the "nginx-1" pod.
+	if err := f.DeletePod(pod1.Namespace, pod1.Name); err != nil {
+		t.Fatal(err)
+	}
+
+	// Wait for the "nginx-1-Y" pod to be reported as having been marked for deletion.
+	if err := f.WaitUntilPodDeleted(pod1.Namespace, pod1.Name); err != nil {
+		t.Fatal(err)
+	}
+
+	// Grab the stats from the provider.
+	stats, err = f.GetStatsSummary()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Make sure the "nginx-1-Y" pod DOES NOT exist in the slice of PodStats anymore.
+	if _, err := findPodInPodStats(stats, pod1); err == nil {
+		t.Fatalf("expected to NOT find pod \"%s/%s\" in the slice of pod stats", pod1.Namespace, pod1.Name)
+	}
+}
+
+// findPodInPodStats returns the index of the specified pod in the .pods field of the specified Summary object.
+// It returns an error if the specified pod is not found.
+func findPodInPodStats(summary *v1alpha1.Summary, pod *v1.Pod) (int, error) {
+	for i, p := range summary.Pods {
+		if p.PodRef.Namespace == pod.Namespace && p.PodRef.Name == pod.Name && string(p.PodRef.UID) == string(pod.UID) {
+			return i, nil
+		}
+	}
+	return -1, fmt.Errorf("failed to find pod \"%s/%s\" in the slice of pod stats", pod.Namespace, pod.Name)
+}