add section for PlacementDisruptionBudget

Azure · Jan 19, 2025 · 0e327a0 · 0e327a0
1 parent 336b805
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diff --git a/docs/howtos/eviction-placement-disruption-budget.md b/docs/howtos/eviction-placement-disruption-budget.md
@@ -22,6 +22,7 @@ kubectl create ns test-ns
 Then we will apply a `ClusterResourcePlacement` with the following spec:
 
 ```yaml
+spec:
   resourceSelectors:
     - group: ""
       kind: Namespace
@@ -188,4 +189,168 @@ status:
       version: v1
 ```
 
-The status shows that the resources have been removed from the cluster and the only reason the scheduler doesn't re-pick the cluster is because of the taint we added.
+The status shows that the resources have been removed from the cluster and the only reason the scheduler doesn't re-pick the cluster is because of the taint we added.
+
+## Protecting resources from voluntary disruptions using ClusterResourcePlacementDisruptionBudget
+
+In this example, we will create a ClusterResourcePlacement object with PickN placement policy to propagate resources to an existing MemberCluster,
+then create a ClusterResourcePlacementDisruptionBudget object to protect resources on the MemberCluster from voluntary disruption and 
+then try to evict resources from the MemberCluster.
+
+We will first create a namespace that we will propagate to the member cluster
+
+```
+kubectl create ns test-ns
+```
+
+Then we will apply a `ClusterResourcePlacement` with the following spec:
+
+```yaml
+spec:
+  resourceSelectors:
+    - group: ""
+      kind: Namespace
+      version: v1
+      name: test-ns
+  policy:
+    placementType: PickN
+    numberOfClusters: 1
+```
+
+The CRP status after applying should look something like this:
+
+```yaml
+status:
+  conditions:
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: found all cluster needed as specified by the scheduling policy, found
+      1 cluster(s)
+    observedGeneration: 2
+    reason: SchedulingPolicyFulfilled
+    status: "True"
+    type: ClusterResourcePlacementScheduled
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: All 1 cluster(s) start rolling out the latest resource
+    observedGeneration: 2
+    reason: RolloutStarted
+    status: "True"
+    type: ClusterResourcePlacementRolloutStarted
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: No override rules are configured for the selected resources
+    observedGeneration: 2
+    reason: NoOverrideSpecified
+    status: "True"
+    type: ClusterResourcePlacementOverridden
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: Works(s) are succcesfully created or updated in 1 target cluster(s)'
+      namespaces
+    observedGeneration: 2
+    reason: WorkSynchronized
+    status: "True"
+    type: ClusterResourcePlacementWorkSynchronized
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: The selected resources are successfully applied to 1 cluster(s)
+    observedGeneration: 2
+    reason: ApplySucceeded
+    status: "True"
+    type: ClusterResourcePlacementApplied
+  - lastTransitionTime: "2025-01-19T12:36:54Z"
+    message: The selected resources in 1 cluster(s) are available now
+    observedGeneration: 2
+    reason: ResourceAvailable
+    status: "True"
+    type: ClusterResourcePlacementAvailable
+  observedResourceIndex: "0"
+  placementStatuses:
+  - clusterName: kind-cluster-1
+    conditions:
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: 'Successfully scheduled resources for placement in "kind-cluster-1"
+        (affinity score: 0, topology spread score: 0): picked by scheduling policy'
+      observedGeneration: 2
+      reason: Scheduled
+      status: "True"
+      type: Scheduled
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: Detected the new changes on the resources and started the rollout process
+      observedGeneration: 2
+      reason: RolloutStarted
+      status: "True"
+      type: RolloutStarted
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: No override rules are configured for the selected resources
+      observedGeneration: 2
+      reason: NoOverrideSpecified
+      status: "True"
+      type: Overridden
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: All of the works are synchronized to the latest
+      observedGeneration: 2
+      reason: AllWorkSynced
+      status: "True"
+      type: WorkSynchronized
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: All corresponding work objects are applied
+      observedGeneration: 2
+      reason: AllWorkHaveBeenApplied
+      status: "True"
+      type: Applied
+    - lastTransitionTime: "2025-01-19T12:36:54Z"
+      message: All corresponding work objects are available
+      observedGeneration: 2
+      reason: AllWorkAreAvailable
+      status: "True"
+      type: Available
+  selectedResources:
+  - kind: Namespace
+    name: test-ns
+    version: v1
+```
+> **Note:** The `ClusterResourcePlacementDisruptionBudget` object is only used as an information source by the eviction controller and hence it doesn't have a status associated to it at the moment.
+> 
+Now we will create a `ClusterResourcePlacementDisruptionBudget` object to protect resources on the member cluster from voluntary disruption:
+
+```yaml
+apiVersion: placement.kubernetes-fleet.io/v1beta1
+kind: ClusterResourcePlacementDisruptionBudget
+metadata:
+  name: test-crp
+spec:
+  minAvailable: 1
+```
+
+> **Note:** An eviction object is only reconciled once after which it reaches a terminal state, if the user desires to use the same eviction object they need to delete the existing eviction object and re-create the object for the eviction to occur again.
+
+Now we will create a `ClusterResourcePlacementEviction` object to evict resources from the member cluster:
+
+```yaml
+apiVersion: placement.kubernetes-fleet.io/v1beta1
+kind: ClusterResourcePlacementEviction
+metadata:
+  name: test-eviction
+spec:
+  placementName: test-crp
+  clusterName: kind-cluster-1
+```
+
+let's take a look at the status to see if the eviction was executed,
+
+```yaml
+status:
+  conditions:
+  - lastTransitionTime: "2025-01-19T12:48:42Z"
+    message: Eviction is valid
+    observedGeneration: 1
+    reason: ClusterResourcePlacementEvictionValid
+    status: "True"
+    type: Valid
+  - lastTransitionTime: "2025-01-19T12:48:42Z"
+    message: 'Eviction is blocked by specified ClusterResourcePlacementDisruptionBudget,
+      availablePlacements: 1, totalPlacements: 1'
+    observedGeneration: 1
+    reason: ClusterResourcePlacementEvictionNotExecuted
+    status: "False"
+    type: Executed
+```
+
+from the eviction status we can clearly see the eviction was blocked by the `ClusterResourcePlacementDisruptionBudget` object which protected resources from being evicted.
diff --git a/examples/eviction/clusterpdb.yaml b/examples/eviction/clusterpdb.yaml
@@ -1,6 +1,6 @@
-apiVersion: placement.kubernetes-fleet.io/v1alpha1
+apiVersion: placement.kubernetes-fleet.io/v1beta1
 kind: ClusterResourcePlacementDisruptionBudget
 metadata:
   name: test-crp
 spec:
-  maxUnavailable: 1
+  minAvailable: 1