Add functionality for resolveConflicts: PRESERVE

Author: Edmond Ceausu

config/crd/bases/controlplane.cluster.x-k8s.io_awsmanagedcontrolplanes.yaml

@@ -91,6 +91,7 @@ spec:
                       enum:
                       - overwrite
                       - none
+                      - preserve
                       type: string
                     name:
                       description: Name is the name of the addon

controlplane/eks/api/v1beta1/types.go

@@ -154,6 +154,10 @@ var (
 	// AddonResolutionNone indicates that if there are parameter conflicts then
 	// resolution will not be done and an error will be reported.
 	AddonResolutionNone = AddonResolution("none")
+
+	// AddonResolutionPreserve indicates that if there are parameter conflicts then
+	// resolution will result in preserving the existing value
+	AddonResolutionPreserve = AddonResolution("preserve")
 )
 
 // AddonStatus defines the status for an addon.

controlplane/eks/api/v1beta2/types.go

@@ -154,6 +154,10 @@ var (
 	// AddonResolutionNone indicates that if there are parameter conflicts then
 	// resolution will not be done and an error will be reported.
 	AddonResolutionNone = AddonResolution("none")
+
+	// AddonResolutionPreserve indicates that if there are parameter conflicts then
+	// resolution will result in preserving the existing value
+	AddonResolutionPreserve = AddonResolution("preserve")
 )
 
 // AddonStatus defines the status for an addon.

docs/book/src/topics/eks/addons.md

@@ -23,8 +23,15 @@ spec:
       conflictResolution: "overwrite"
 ```
 
-_Note_: For `conflictResolution` `overwrite` is the **default** behaviour. That means, if not otherwise specified, it's
-set to `overwrite`.
+Valid values are:
+```
+none
+overwrite
+preserve
+```
+
+_Note_: For `conflictResolution` `none` is the **default** behaviour. That means, if not otherwise specified, it's
+set to `none`. Review [API Documentation](https://docs.aws.amazon.com/eks/latest/APIReference/API_CreateAddon.html#AmazonEKS-CreateAddon-request-resolveConflicts) for detailed behavior.
 
 Additionally, there is a cluster [flavor](https://cluster-api.sigs.k8s.io/clusterctl/commands/generate-cluster.html#flavors)
 called [eks-managedmachinepool-vpccni](https://github.com/kubernetes-sigs/cluster-api-provider-aws/blob/main/templates/cluster-template-eks-managedmachinepool-vpccni.yaml) that you can use with **clusterctl**:
@@ -46,6 +53,8 @@ To update the version of an addon you need to edit the `AWSManagedControlPlane`
 ...
 ```
 
+_Note_: For `conflictResolution` `none`, updating may fail if a change was made to the addon that is unexpected by EKS. Review [API Documentation](https://docs.aws.amazon.com/eks/latest/APIReference/API_UpdateAddon.html#AmazonEKS-UpdateAddon-request-resolveConflicts) for detailed behavior on conflict resolution.
+
 ## Deleting Addons
 
 To delete an addon from a cluster you need to edit the `AWSManagedControlPlane` instance and remove the entry for the addon you want to delete.

pkg/cloud/services/eks/addons.go

@@ -194,12 +194,16 @@ func (s *Service) translateAPIToAddon(addons []ekscontrolplanev1.Addon) []*eksad
 
 	for i := range addons {
 		addon := addons[i]
+		conflict, err := convertConflictResolution(*addon.ConflictResolution)
+		if err != nil {
+			s.scope.Error(err, err.Error())
+		}
 		convertedAddon := &eksaddons.EKSAddon{
 			Name:                  &addon.Name,
 			Version:               &addon.Version,
 			Configuration:         &addon.Configuration,
 			Tags:                  ngTags(s.scope.Cluster.Name, s.scope.AdditionalTags()),
-			ResolveConflict:       convertConflictResolution(*addon.ConflictResolution),
+			ResolveConflict:       conflict,
 			ServiceAccountRoleARN: addon.ServiceAccountRoleArn,
 		}
 
@@ -209,9 +213,19 @@ func (s *Service) translateAPIToAddon(addons []ekscontrolplanev1.Addon) []*eksad
 	return converted
 }
 
-func convertConflictResolution(conflict ekscontrolplanev1.AddonResolution) *string {
-	if conflict == ekscontrolplanev1.AddonResolutionNone {
-		return aws.String(eks.ResolveConflictsNone)
+func convertConflictResolution(conflict ekscontrolplanev1.AddonResolution) (*string, error) {
+	switch conflict {
+	case ekscontrolplanev1.AddonResolutionNone:
+		return aws.String(eks.ResolveConflictsNone), nil
+
+	case ekscontrolplanev1.AddonResolutionOverwrite:
+		return aws.String(eks.ResolveConflictsOverwrite), nil
+
+	case ekscontrolplanev1.AddonResolutionPreserve:
+		return aws.String(eks.ResolveConflictsPreserve), nil
+
+	default:
+		return aws.String(eks.ResolveConflictsNone), fmt.Errorf("failed to determine adddonResolution; defaulting to None")
+
 	}
-	return aws.String(eks.ResolveConflictsOverwrite)
 }