// Check that the pods comprising a service get spread evenly across available zones
func SpreadServiceOrFail(f *framework.Framework, replicaCount int, image string) {
// First create the service
serviceName := "test-service"
serviceSpec := &v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: serviceName,
Namespace: f.Namespace.Name,
},
Spec: v1.ServiceSpec{
Selector: map[string]string{
"service": serviceName,
},
Ports: []v1.ServicePort{{
Port: 80,
TargetPort: intstr.FromInt(80),
}},
},
}
_, err := f.ClientSet.Core().Services(f.Namespace.Name).Create(serviceSpec)
Expect(err).NotTo(HaveOccurred())
// Now create some pods behind the service
podSpec := &v1.Pod{
ObjectMeta: metav1.ObjectMeta{
Name: serviceName,
Labels: map[string]string{"service": serviceName},
},
Spec: v1.PodSpec{
Containers: []v1.Container{
{
Name: "test",
Image: framework.GetPauseImageName(f.ClientSet),
},
},
},
}
// Caution: StartPods requires at least one pod to replicate.
// Based on the callers, replicas is always positive number: zoneCount >= 0 implies (2*zoneCount)+1 > 0.
// Thus, no need to test for it. Once the precondition changes to zero number of replicas,
// test for replicaCount > 0. Otherwise, StartPods panics.
framework.ExpectNoError(testutils.StartPods(f.ClientSet, replicaCount, f.Namespace.Name, serviceName, *podSpec, false, framework.Logf))
// Wait for all of them to be scheduled
selector := labels.SelectorFromSet(labels.Set(map[string]string{"service": serviceName}))
pods, err := framework.WaitForPodsWithLabelScheduled(f.ClientSet, f.Namespace.Name, selector)
Expect(err).NotTo(HaveOccurred())
// Now make sure they're spread across zones
zoneNames, err := getZoneNames(f.ClientSet)
Expect(err).NotTo(HaveOccurred())
Expect(checkZoneSpreading(f.ClientSet, pods, zoneNames)).To(Equal(true))
}
totalPodCapacity += podCapacity.Value()
}
currentlyScheduledPods := framework.WaitForStableCluster(c, masterNodes)
podsNeededForSaturation := int(totalPodCapacity) - currentlyScheduledPods
By(fmt.Sprintf("Starting additional %v Pods to fully saturate the cluster max pods and trying to start another one", podsNeededForSaturation))
// As the pods are distributed randomly among nodes,
// it can easily happen that all nodes are satured
// and there is no need to create additional pods.
// StartPods requires at least one pod to replicate.
if podsNeededForSaturation > 0 {
framework.ExpectNoError(testutils.StartPods(c, podsNeededForSaturation, ns, "maxp",
*initPausePod(f, pausePodConfig{
Name: "",
Labels: map[string]string{"name": ""},
}), true, framework.Logf))
}
podName := "additional-pod"
createPausePod(f, pausePodConfig{
Name: podName,
Labels: map[string]string{"name": "additional"},
})
waitForScheduler()
verifyResult(c, podsNeededForSaturation, 1, ns)
})
// This test verifies we don't allow scheduling of pods in a way that sum of limits of pods is greater than machines capacity.
// It assumes that cluster add-on pods stay stable and cannot be run in parallel with any other test that touches Nodes or Pods.
// It is so because we need to have precise control on what's running in the cluster.