Merge pull request #33143 from mml/off_by_one_._._._the_story_of_an_engineer

Automatic merge from submit-queue

Only approve evictions when budgets would stay enforced after.

Prior to this, we would approve eviction as long as the current state of
the pods matched the budget.  The new version requires that after the
eviction, the pods would still match the budget.

Also update tests to match.
This commit is contained in:
Kubernetes Submit Queue 2016-09-20 19:05:18 -07:00 committed by GitHub
commit 31379c102d
3 changed files with 54 additions and 42 deletions

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@ -564,7 +564,7 @@ func (dc *DisruptionController) updatePdbSpec(pdb *policy.PodDisruptionBudget, c
// pods are in a safe state when their first pods appear but this controller
// has not updated their status yet. This isn't the only race, but it's a
// common one that's easy to detect.
disruptionAllowed := currentHealthy >= desiredHealthy && expectedCount > 0
disruptionAllowed := currentHealthy-1 >= desiredHealthy && expectedCount > 0
if pdb.Status.CurrentHealthy == currentHealthy && pdb.Status.DesiredHealthy == desiredHealthy && pdb.Status.ExpectedPods == expectedCount && pdb.Status.PodDisruptionAllowed == disruptionAllowed {
return nil

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@ -266,14 +266,14 @@ func TestUnavailable(t *testing.T) {
// Add three pods, verifying that the counts go up at each step.
pods := []*api.Pod{}
for i := int32(0); i < 3; i++ {
for i := int32(0); i < 4; i++ {
ps.VerifyPdbStatus(t, pdbName, false, i, 3, i)
pod, _ := newPod(t, fmt.Sprintf("yo-yo-yo %d", i))
pods = append(pods, pod)
add(t, dc.podLister.Indexer, pod)
dc.sync(pdbName)
}
ps.VerifyPdbStatus(t, pdbName, true, 3, 3, 3)
ps.VerifyPdbStatus(t, pdbName, true, 4, 3, 4)
// Now set one pod as unavailable
pods[0].Status.Conditions = []api.PodCondition{}
@ -281,7 +281,7 @@ func TestUnavailable(t *testing.T) {
dc.sync(pdbName)
// Verify expected update
ps.VerifyPdbStatus(t, pdbName, false, 2, 3, 3)
ps.VerifyPdbStatus(t, pdbName, false, 3, 3, 4)
}
// Create a pod with no controller, and verify that a PDB with a percentage
@ -366,8 +366,8 @@ func TestReplicationController(t *testing.T) {
dc, ps := newFakeDisruptionController()
// 67% should round up to 3
pdb, pdbName := newPodDisruptionBudget(t, intstr.FromString("67%"))
// 34% should round up to 2
pdb, pdbName := newPodDisruptionBudget(t, intstr.FromString("34%"))
add(t, dc.pdbLister.Store, pdb)
rc, _ := newReplicationController(t, 3)
rc.Spec.Selector = labels
@ -386,9 +386,9 @@ func TestReplicationController(t *testing.T) {
add(t, dc.podLister.Indexer, pod)
dc.sync(pdbName)
if i < 2 {
ps.VerifyPdbStatus(t, pdbName, false, i+1, 3, 3)
ps.VerifyPdbStatus(t, pdbName, false, i+1, 2, 3)
} else {
ps.VerifyPdbStatus(t, pdbName, true, 3, 3, 3)
ps.VerifyPdbStatus(t, pdbName, true, 3, 2, 3)
}
}
@ -411,9 +411,18 @@ func TestTwoControllers(t *testing.T) {
}
dc, ps := newFakeDisruptionController()
// These constants are related, but I avoid calculating the correct values in
// code. If you update a parameter here, recalculate the correct values for
// all of them. Further down in the test, we use these to control loops, and
// that level of logic is enough complexity for me.
const collectionSize int32 = 11 // How big each collection is
const minAvailable string = "28%" // minAvailable we'll specify
const minimumOne int32 = 4 // integer minimum with one controller
const minimumTwo int32 = 7 // integer minimum with two controllers
pdb, pdbName := newPodDisruptionBudget(t, intstr.FromString("28%"))
add(t, dc.pdbLister.Store, pdb)
rc, _ := newReplicationController(t, 11)
rc, _ := newReplicationController(t, collectionSize)
rc.Spec.Selector = rcLabels
add(t, dc.rcLister.Indexer, rc)
dc.sync(pdbName)
@ -422,71 +431,74 @@ func TestTwoControllers(t *testing.T) {
pods := []*api.Pod{}
for i := int32(0); i < 11; i++ {
unavailablePods := collectionSize - minimumOne - 1
for i := int32(1); i <= collectionSize; i++ {
pod, _ := newPod(t, fmt.Sprintf("quux %d", i))
pods = append(pods, pod)
pod.Labels = rcLabels
if i < 7 {
if i <= unavailablePods {
pod.Status.Conditions = []api.PodCondition{}
}
add(t, dc.podLister.Indexer, pod)
dc.sync(pdbName)
if i < 7 {
ps.VerifyPdbStatus(t, pdbName, false, 0, 4, 11)
} else if i < 10 {
ps.VerifyPdbStatus(t, pdbName, false, i-6, 4, 11)
if i <= unavailablePods {
ps.VerifyPdbStatus(t, pdbName, false, 0, minimumOne, collectionSize)
} else if i-unavailablePods <= minimumOne {
ps.VerifyPdbStatus(t, pdbName, false, i-unavailablePods, minimumOne, collectionSize)
} else {
ps.VerifyPdbStatus(t, pdbName, true, 4, 4, 11)
ps.VerifyPdbStatus(t, pdbName, true, i-unavailablePods, minimumOne, collectionSize)
}
}
d, _ := newDeployment(t, 11)
d, _ := newDeployment(t, collectionSize)
d.Spec.Selector = newSel(dLabels)
add(t, dc.dLister.Indexer, d)
dc.sync(pdbName)
ps.VerifyPdbStatus(t, pdbName, true, 4, 4, 11)
ps.VerifyPdbStatus(t, pdbName, true, minimumOne+1, minimumOne, collectionSize)
rs, _ := newReplicaSet(t, 11)
rs, _ := newReplicaSet(t, collectionSize)
rs.Spec.Selector = newSel(dLabels)
rs.Labels = dLabels
add(t, dc.rsLister.Store, rs)
dc.sync(pdbName)
ps.VerifyPdbStatus(t, pdbName, true, 4, 4, 11)
ps.VerifyPdbStatus(t, pdbName, true, minimumOne+1, minimumOne, collectionSize)
for i := int32(0); i < 11; i++ {
// By the end of this loop, the number of ready pods should be N+2 (hence minimumTwo+2).
unavailablePods = 2*collectionSize - (minimumTwo + 2) - unavailablePods
for i := int32(1); i <= collectionSize; i++ {
pod, _ := newPod(t, fmt.Sprintf("quuux %d", i))
pods = append(pods, pod)
pod.Labels = dLabels
if i < 7 {
if i <= unavailablePods {
pod.Status.Conditions = []api.PodCondition{}
}
add(t, dc.podLister.Indexer, pod)
dc.sync(pdbName)
if i < 7 {
ps.VerifyPdbStatus(t, pdbName, false, 4, 7, 22)
} else if i < 9 {
ps.VerifyPdbStatus(t, pdbName, false, 4+i-6, 7, 22)
if i <= unavailablePods {
ps.VerifyPdbStatus(t, pdbName, false, minimumOne+1, minimumTwo, 2*collectionSize)
} else if i-unavailablePods <= minimumTwo-(minimumOne+1) {
ps.VerifyPdbStatus(t, pdbName, false, (minimumOne+1)+(i-unavailablePods), minimumTwo, 2*collectionSize)
} else {
ps.VerifyPdbStatus(t, pdbName, true, 4+i-6, 7, 22)
ps.VerifyPdbStatus(t, pdbName, true, (minimumOne+1)+(i-unavailablePods), minimumTwo, 2*collectionSize)
}
}
// Now we verify we can bring down 1 pod and a disruption is still permitted,
// but if we bring down two, it's not. Then we make the pod ready again and
// verify that a disruption is permitted again.
ps.VerifyPdbStatus(t, pdbName, true, 8, 7, 22)
pods[10].Status.Conditions = []api.PodCondition{}
update(t, dc.podLister.Indexer, pods[10])
ps.VerifyPdbStatus(t, pdbName, true, 2+minimumTwo, minimumTwo, 2*collectionSize)
pods[collectionSize-1].Status.Conditions = []api.PodCondition{}
update(t, dc.podLister.Indexer, pods[collectionSize-1])
dc.sync(pdbName)
ps.VerifyPdbStatus(t, pdbName, true, 7, 7, 22)
ps.VerifyPdbStatus(t, pdbName, true, 1+minimumTwo, minimumTwo, 2*collectionSize)
pods[9].Status.Conditions = []api.PodCondition{}
update(t, dc.podLister.Indexer, pods[9])
pods[collectionSize-2].Status.Conditions = []api.PodCondition{}
update(t, dc.podLister.Indexer, pods[collectionSize-2])
dc.sync(pdbName)
ps.VerifyPdbStatus(t, pdbName, false, 6, 7, 22)
ps.VerifyPdbStatus(t, pdbName, false, minimumTwo, minimumTwo, 2*collectionSize)
pods[10].Status.Conditions = []api.PodCondition{{Type: api.PodReady, Status: api.ConditionTrue}}
update(t, dc.podLister.Indexer, pods[10])
pods[collectionSize-1].Status.Conditions = []api.PodCondition{{Type: api.PodReady, Status: api.ConditionTrue}}
update(t, dc.podLister.Indexer, pods[collectionSize-1])
dc.sync(pdbName)
ps.VerifyPdbStatus(t, pdbName, true, 7, 7, 22)
ps.VerifyPdbStatus(t, pdbName, true, 1+minimumTwo, minimumTwo, 2*collectionSize)
}

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@ -61,7 +61,7 @@ var _ = framework.KubeDescribe("DisruptionController", func() {
It("should update PodDisruptionBudget status", func() {
createPodDisruptionBudgetOrDie(cs, ns, intstr.FromInt(2))
createPodsOrDie(cs, ns, 2)
createPodsOrDie(cs, ns, 3)
// Since disruptionAllowed starts out false, if we see it ever become true,
// that means the controller is working.
@ -92,22 +92,22 @@ var _ = framework.KubeDescribe("DisruptionController", func() {
}, {
description: "too few pods, absolute",
minAvailable: intstr.FromInt(2),
podCount: 1,
podCount: 2,
shouldDeny: true,
}, {
description: "enough pods, absolute",
minAvailable: intstr.FromInt(2),
podCount: 2,
podCount: 3,
shouldDeny: false,
}, {
description: "enough pods, replicaSet, percentage",
minAvailable: intstr.FromString("100%"),
minAvailable: intstr.FromString("90%"),
replicaSetSize: 10,
exclusive: false,
shouldDeny: false,
}, {
description: "too few pods, replicaSet, percentage",
minAvailable: intstr.FromString("100%"),
minAvailable: intstr.FromString("90%"),
replicaSetSize: 10,
exclusive: true,
shouldDeny: true,