interface: update apply strategy to call out allowing co-ownership ex…

…plicitly (Azure#737)
britaniar · Mar 27, 2024 · 71e6caf · 71e6caf
1 parent 72b325a
commit 71e6caf
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Showing 5 changed files with 59 additions and 20 deletions.
diff --git a/apis/placement/v1beta1/clusterresourceplacement_types.go b/apis/placement/v1beta1/clusterresourceplacement_types.go
@@ -427,16 +427,24 @@ type RolloutStrategy struct {
 }
 
 // ApplyStrategy describes how to resolve the conflict if the resource to be placed already exists in the target cluster
-// and is owned by other appliers.
+// and whether it's allowed to be co-owned by other non-fleet appliers.
 // Note: If multiple CRPs try to place the same resource with different apply strategy, the later ones will fail with the
 // reason ApplyConflictBetweenPlacements.
 type ApplyStrategy struct {
-	// Type defines the type of strategy to use. Default to FailIfExists.
-	// +kubebuilder:default=FailIfExists
-	// +kubebuilder:validation:Enum=FailIfExists;ServerSideApply
+	// Type defines the type of strategy to use. Default to ClientSideApply.
+	// Server-side apply is a safer choice. Read more about the differences between server-side apply and client-side
+	// apply: https://kubernetes.io/docs/reference/using-api/server-side-apply/#comparison-with-client-side-apply.
+	// +kubebuilder:default=ClientSideApply
+	// +kubebuilder:validation:Enum=ClientSideApply;ServerSideApply
 	// +optional
 	Type ApplyStrategyType `json:"type,omitempty"`
 
+	// AllowCoOwnership defines whether to apply the resource if it already exists in the target cluster and is not
+	// solely owned by fleet (i.e., metadata.ownerReferences contains only fleet custom resources).
+	// If true, apply the resource and add fleet as a co-owner.
+	// If false, leave the resource unchanged and fail the apply.
+	AllowCoOwnership bool `json:"allowCoOwnership,omitempty"`
+
 	// ServerSideApplyConfig defines the configuration for server side apply. It is honored only when type is ServerSideApply.
 	// +optional
 	ServerSideApplyConfig *ServerSideApplyConfig `json:"serverSideApplyConfig,omitempty"`
@@ -448,9 +456,10 @@ type ApplyStrategy struct {
 type ApplyStrategyType string
 
 const (
-	// ApplyStrategyTypeFailIfExists will fail to apply a resource if it already exists in the target cluster and is owned
-	// by other appliers.
-	ApplyStrategyTypeFailIfExists ApplyStrategyType = "FailIfExists"
+	// ApplyStrategyTypeClientSideApply will use three-way merge patch similar to how `kubectl apply` does by storing
+	// last applied state in the `last-applied-configuration` annotation.
+	// When the `last-applied-configuration` annotation size is greater than 256kB, it falls back to the server-side apply.
+	ApplyStrategyTypeClientSideApply ApplyStrategyType = "ClientSideApply"
 
 	// ApplyStrategyTypeServerSideApply will use server-side apply to resolve conflicts between the resource to be placed
 	// and the existing resource in the target cluster.

diff --git a/config/crd/bases/placement.kubernetes-fleet.io_clusterresourcebindings.yaml b/config/crd/bases/placement.kubernetes-fleet.io_clusterresourcebindings.yaml
@@ -56,6 +56,14 @@ spec:
                   the resource to be placed already exists in the target cluster and
                   is owned by other appliers.
                 properties:
+                  allowCoOwnership:
+                    description: AllowCoOwnership defines whether to apply the resource
+                      if it already exists in the target cluster and is not solely
+                      owned by fleet (i.e., metadata.ownerReferences contains only
+                      fleet custom resources). If true, apply the resource and add
+                      fleet as a co-owner. If false, leave the resource unchanged
+                      and fail the apply.
+                    type: boolean
                   serverSideApplyConfig:
                     description: ServerSideApplyConfig defines the configuration for
                       server side apply. It is honored only when type is ServerSideApply.
@@ -72,11 +80,13 @@ spec:
                         type: boolean
                     type: object
                   type:
-                    default: FailIfExists
-                    description: Type defines the type of strategy to use. Default
-                      to FailIfExists.
+                    default: ClientSideApply
+                    description: 'Type defines the type of strategy to use. Default
+                      to ClientSideApply. Server-side apply is a safer choice. Read
+                      more about the differences between server-side apply and client-side
+                      apply: https://kubernetes.io/docs/reference/using-api/server-side-apply/#comparison-with-client-side-apply.'
                     enum:
-                    - FailIfExists
+                    - ClientSideApply
                     - ServerSideApply
                     type: string
                 type: object

diff --git a/config/crd/bases/placement.kubernetes-fleet.io_clusterresourceplacements.yaml b/config/crd/bases/placement.kubernetes-fleet.io_clusterresourceplacements.yaml
@@ -624,6 +624,14 @@ spec:
                       if the resource to be placed already exists in the target cluster
                       and is owned by other appliers.
                     properties:
+                      allowCoOwnership:
+                        description: AllowCoOwnership defines whether to apply the
+                          resource if it already exists in the target cluster and
+                          is not solely owned by fleet (i.e., metadata.ownerReferences
+                          contains only fleet custom resources). If true, apply the
+                          resource and add fleet as a co-owner. If false, leave the
+                          resource unchanged and fail the apply.
+                        type: boolean
                       serverSideApplyConfig:
                         description: ServerSideApplyConfig defines the configuration
                           for server side apply. It is honored only when type is ServerSideApply.
@@ -641,11 +649,13 @@ spec:
                             type: boolean
                         type: object
                       type:
-                        default: FailIfExists
-                        description: Type defines the type of strategy to use. Default
-                          to FailIfExists.
+                        default: ClientSideApply
+                        description: 'Type defines the type of strategy to use. Default
+                          to ClientSideApply. Server-side apply is a safer choice.
+                          Read more about the differences between server-side apply
+                          and client-side apply: https://kubernetes.io/docs/reference/using-api/server-side-apply/#comparison-with-client-side-apply.'
                         enum:
-                        - FailIfExists
+                        - ClientSideApply
                         - ServerSideApply
                         type: string
                     type: object

diff --git a/config/crd/bases/placement.kubernetes-fleet.io_works.yaml b/config/crd/bases/placement.kubernetes-fleet.io_works.yaml
@@ -42,6 +42,14 @@ spec:
                   the resource to be placed already exists in the target cluster and
                   is owned by other appliers.
                 properties:
+                  allowCoOwnership:
+                    description: AllowCoOwnership defines whether to apply the resource
+                      if it already exists in the target cluster and is not solely
+                      owned by fleet (i.e., metadata.ownerReferences contains only
+                      fleet custom resources). If true, apply the resource and add
+                      fleet as a co-owner. If false, leave the resource unchanged
+                      and fail the apply.
+                    type: boolean
                   serverSideApplyConfig:
                     description: ServerSideApplyConfig defines the configuration for
                       server side apply. It is honored only when type is ServerSideApply.
@@ -58,11 +66,13 @@ spec:
                         type: boolean
                     type: object
                   type:
-                    default: FailIfExists
-                    description: Type defines the type of strategy to use. Default
-                      to FailIfExists.
+                    default: ClientSideApply
+                    description: 'Type defines the type of strategy to use. Default
+                      to ClientSideApply. Server-side apply is a safer choice. Read
+                      more about the differences between server-side apply and client-side
+                      apply: https://kubernetes.io/docs/reference/using-api/server-side-apply/#comparison-with-client-side-apply.'
                     enum:
-                    - FailIfExists
+                    - ClientSideApply
                     - ServerSideApply
                     type: string
                 type: object

diff --git a/pkg/utils/validator/clusterresourceplacement_test.go b/pkg/utils/validator/clusterresourceplacement_test.go
@@ -353,7 +353,7 @@ func TestValidateClusterResourcePlacement_RolloutStrategy(t *testing.T) {
 			strategy: placementv1beta1.RolloutStrategy{
 				Type: placementv1beta1.RollingUpdateRolloutStrategyType,
 				ApplyStrategy: &placementv1beta1.ApplyStrategy{
-					Type: placementv1beta1.ApplyStrategyTypeFailIfExists,
+					Type: placementv1beta1.ApplyStrategyTypeClientSideApply,
 					ServerSideApplyConfig: &placementv1beta1.ServerSideApplyConfig{
 						ForceConflicts: false,
 					},