Skip to content

Commit

Permalink
allow pod scheduling if they express soft pod affinity / anti affinity (
Browse files Browse the repository at this point in the history 
#1541)

* allow pod scheduling if they express soft pod affinity / anti affinity

* changed error message to make it more clear

Co-authored-by: Ellis Tarn <[email protected]>

* improved error message to make it clearer

* added pod affinity and anti-affinity preferences relaxation

Co-authored-by: Ellis Tarn <[email protected]>
  • Loading branch information
@cebernardi @ellistarn
cebernardi and ellistarn authored Mar 21, 2022
1 parent e169aa7 commit 08c4218
Show file tree
Hide file tree
Showing 4 changed files with 119 additions and 17 deletions.
8 changes: 4 additions & 4 deletions pkg/controllers/selection/controller.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,11 +142,11 @@ func validateAffinity(p *v1.Pod) (errs error) {
if p.Spec.Affinity == nil {
return nil
}
if pod.HasPodAffinity(p) {
errs = multierr.Append(errs, fmt.Errorf("pod affinity is not supported"))
if pod.HasRequiredPodAffinity(p) {
errs = multierr.Append(errs, fmt.Errorf("pod affinity rule 'requiredDuringSchedulingIgnoreDuringExecution' is not supported"))
}
if pod.HasPodAntiAffinity(p) {
errs = multierr.Append(errs, fmt.Errorf("pod anti-affinity is not supported"))
if pod.HasRequiredPodAntiAffinity(p) {
errs = multierr.Append(errs, fmt.Errorf("pod anti-affinity rule 'requiredDuringSchedulingIgnoreDuringExecution' is not supported"))
}
if p.Spec.Affinity.NodeAffinity != nil {
for _, term := range p.Spec.Affinity.NodeAffinity.PreferredDuringSchedulingIgnoredDuringExecution {
Expand Down
32 changes: 32 additions & 0 deletions pkg/controllers/selection/preferences.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,8 @@ func (p *Preferences) Relax(ctx context.Context, pod *v1.Pod) {

func (p *Preferences) relax(ctx context.Context, pod *v1.Pod) bool {
for _, relaxFunc := range []func(*v1.Pod) *string{
func(pod *v1.Pod) *string { return p.removePreferredPodAffinityTerm(pod) },
func(pod *v1.Pod) *string { return p.removePreferredPodAntiAffinityTerm(pod) },
func(pod *v1.Pod) *string { return p.removePreferredNodeAffinityTerm(pod) },
func(pod *v1.Pod) *string { return p.removeRequiredNodeAffinityTerm(pod) },
func(pod *v1.Pod) *string { return p.toleratePreferNoScheduleTaints(pod) },
Expand Down Expand Up @@ -98,6 +100,36 @@ func (p *Preferences) removePreferredNodeAffinityTerm(pod *v1.Pod) *string {
return nil
}

func (p *Preferences) removePreferredPodAffinityTerm(pod *v1.Pod) *string {
if pod.Spec.Affinity == nil || pod.Spec.Affinity.PodAffinity == nil || len(pod.Spec.Affinity.PodAffinity.PreferredDuringSchedulingIgnoredDuringExecution) == 0 {
return nil
}
terms := pod.Spec.Affinity.PodAffinity.PreferredDuringSchedulingIgnoredDuringExecution
// Remove the all the terms
if len(terms) > 0 {
// Sort descending by weight to remove heaviest preferences to try lighter ones
sort.SliceStable(terms, func(i, j int) bool { return terms[i].Weight > terms[j].Weight })
pod.Spec.Affinity.PodAffinity.PreferredDuringSchedulingIgnoredDuringExecution = terms[1:]
return ptr.String(fmt.Sprintf("removing: spec.affinity.podAffinity.preferredDuringSchedulingIgnoredDuringExecution[0]=%s", pretty.Concise(terms[0])))
}
return nil
}

func (p *Preferences) removePreferredPodAntiAffinityTerm(pod *v1.Pod) *string {
if pod.Spec.Affinity == nil || pod.Spec.Affinity.PodAntiAffinity == nil || len(pod.Spec.Affinity.PodAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution) == 0 {
return nil
}
terms := pod.Spec.Affinity.PodAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution
// Remove the all the terms
if len(terms) > 0 {
// Sort descending by weight to remove heaviest preferences to try lighter ones
sort.SliceStable(terms, func(i, j int) bool { return terms[i].Weight > terms[j].Weight })
pod.Spec.Affinity.PodAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution = terms[1:]
return ptr.String(fmt.Sprintf("removing: spec.affinity.podAntiAffinity.preferredDuringSchedulingIgnoredDuringExecution[0]=%s", pretty.Concise(terms[0])))
}
return nil
}

func (p *Preferences) removeRequiredNodeAffinityTerm(pod *v1.Pod) *string {
if pod.Spec.Affinity == nil ||
pod.Spec.Affinity.NodeAffinity == nil ||
Expand Down
80 changes: 75 additions & 5 deletions pkg/controllers/selection/suite_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -179,7 +179,7 @@ var _ = Describe("Preferential Fallback", func() {
})
})
Context("Preferred", func() {
It("should relax all terms", func() {
It("should relax all node affinity terms", func() {
pod := test.UnschedulablePod()
pod.Spec.Affinity = &v1.Affinity{NodeAffinity: &v1.NodeAffinity{PreferredDuringSchedulingIgnoredDuringExecution: []v1.PreferredSchedulingTerm{
{
Expand All @@ -203,6 +203,76 @@ var _ = Describe("Preferential Fallback", func() {
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectScheduled(ctx, env.Client, pod)
})
It("should relax all pod affinity terms", func() {
pod := test.UnschedulablePod()
pod.Spec.Affinity = &v1.Affinity{
PodAffinity: &v1.PodAffinity{PreferredDuringSchedulingIgnoredDuringExecution: []v1.WeightedPodAffinityTerm{
{
Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{
LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
TopologyKey: v1.LabelTopologyZone,
}},
{
Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{
LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
TopologyKey: v1.LabelHostname,
}},
}},
NodeAffinity: &v1.NodeAffinity{PreferredDuringSchedulingIgnoredDuringExecution: []v1.PreferredSchedulingTerm{
{
Weight: 1, Preference: v1.NodeSelectorTerm{MatchExpressions: []v1.NodeSelectorRequirement{
{Key: v1.LabelTopologyZone, Operator: v1.NodeSelectorOpIn, Values: []string{"invalid"}},
}},
}}},
}
// Remove first pod affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Remove second pod affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Remove node affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Success
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectScheduled(ctx, env.Client, pod)
})
It("should relax all pod anti-affinity terms", func() {
pod := test.UnschedulablePod()
pod.Spec.Affinity = &v1.Affinity{
PodAntiAffinity: &v1.PodAntiAffinity{PreferredDuringSchedulingIgnoredDuringExecution: []v1.WeightedPodAffinityTerm{
{
Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{
LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
TopologyKey: v1.LabelTopologyZone,
}},
{
Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{
LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
TopologyKey: v1.LabelHostname,
}},
}},
NodeAffinity: &v1.NodeAffinity{PreferredDuringSchedulingIgnoredDuringExecution: []v1.PreferredSchedulingTerm{
{
Weight: 1, Preference: v1.NodeSelectorTerm{MatchExpressions: []v1.NodeSelectorRequirement{
{Key: v1.LabelTopologyZone, Operator: v1.NodeSelectorOpIn, Values: []string{"invalid"}},
}},
}}},
}
// Remove first pod anti-affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Remove second pod anti-affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Remove node affinity term
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectNotScheduled(ctx, env.Client, pod)
// Success
pod = ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, pod)[0]
ExpectScheduled(ctx, env.Client, pod)
})
It("should relax to use lighter weights", func() {
provisioner.Spec.Requirements = v1alpha5.NewRequirements(
v1.NodeSelectorRequirement{Key: v1.LabelTopologyZone, Operator: v1.NodeSelectorOpIn, Values: []string{"test-zone-1", "test-zone-2"}})
Expand Down Expand Up @@ -321,19 +391,19 @@ var _ = Describe("Pod Affinity and AntiAffinity", func() {
}))[0]
ExpectNotScheduled(ctx, env.Client, pod)
})
It("should not schedule a pod with pod affinity preference", func() {
It("should schedule a pod with pod affinity preference", func() {
ExpectCreated(ctx, env.Client)
pod := ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, test.UnschedulablePod(test.PodOptions{
PodPreferences: []v1.WeightedPodAffinityTerm{{Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{TopologyKey: "foo"}}},
}))[0]
ExpectNotScheduled(ctx, env.Client, pod)
ExpectScheduled(ctx, env.Client, pod)
})
It("should not schedule a pod with pod anti-affinity preference", func() {
It("should schedule a pod with pod anti-affinity preference", func() {
ExpectCreated(ctx, env.Client)
pod := ExpectProvisioned(ctx, env.Client, selectionController, provisioners, provisioner, test.UnschedulablePod(test.PodOptions{
PodAntiPreferences: []v1.WeightedPodAffinityTerm{{Weight: 1, PodAffinityTerm: v1.PodAffinityTerm{TopologyKey: "foo"}}},
}))[0]
ExpectNotScheduled(ctx, env.Client, pod)
ExpectScheduled(ctx, env.Client, pod)
})
It("should schedule a pod with empty pod affinity and anti-affinity", func() {
ExpectCreated(ctx, env.Client)
Expand Down
16 changes: 8 additions & 8 deletions pkg/utils/pod/scheduling.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -68,16 +68,16 @@ func IsOwnedBy(pod *v1.Pod, gvks []schema.GroupVersionKind) bool {
return false
}

// HasPodAffinity returns true if a non-empty PodAffinity is defined in the pod spec
func HasPodAffinity(pod *v1.Pod) bool {
// HasRequiredPodAffinity returns true if a non-empty PodAffinity.RequiredDuringSchedulingIgnoredDuringExecution
// is defined in the pod spec
func HasRequiredPodAffinity(pod *v1.Pod) bool {
return pod.Spec.Affinity.PodAffinity != nil &&
(len(pod.Spec.Affinity.PodAffinity.RequiredDuringSchedulingIgnoredDuringExecution) != 0 ||
len(pod.Spec.Affinity.PodAffinity.PreferredDuringSchedulingIgnoredDuringExecution) != 0)
(len(pod.Spec.Affinity.PodAffinity.RequiredDuringSchedulingIgnoredDuringExecution) != 0)
}

// HasPodAntiAffinity returns true if a non-empty PodAntiAffinity is defined in the pod spec
func HasPodAntiAffinity(pod *v1.Pod) bool {
// HasRequiredPodAntiAffinity returns true if a non-empty PodAntiAffinity/RequiredDuringSchedulingIgnoredDuringExecution
// is defined in the pod spec
func HasRequiredPodAntiAffinity(pod *v1.Pod) bool {
return pod.Spec.Affinity.PodAntiAffinity != nil &&
(len(pod.Spec.Affinity.PodAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution) != 0 ||
len(pod.Spec.Affinity.PodAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution) != 0)
(len(pod.Spec.Affinity.PodAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution) != 0)
}

0 comments on commit 08c4218

Please sign in to comment.