update doc

Author: arshadd-b

docs/proposal/controller-and-user-tags.md

@@ -24,16 +24,19 @@ This proposal presents adding two kinds of tags to the resources created by cont
 
 
 ### Controller tags
- Tags of format`powervs.cluster.x-k8s.io/owner: <cluster-name>` and `powervs.cluster.x-k8s.io/cluster-uuid: UUID` will be added by the controller to newly created cloud resources marking the resource as created by controller. When cluster creation is triggered with clustername "test-cluster", resources "test-cluster-serviceInstance, test-cluster-VPC, test-cluster-loadbalancer, test-cluster-TransitGateway, test-cluster-COSInstance" are created
- When new cluster creation is triggered, if the resources are already present with same name in the cloud. It will lead to security issues because there is a possibilty the existing resources in the cloud belong to different user. So to handle this scenario this tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` is added. During deletion phase the system will look for the presence of both the 
- tags and match inorder to proceed with deletion or to keep as it is. UUID in tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` is cluster object ID
- We will be adding two tags. Below are the cluster creation scenarios.
+ When cluster creation is triggered, resources gets created in the cloud. So to distinguish whether resources are newly created or user has given pre-existing resources,
+ tags of format`powervs.cluster.x-k8s.io/owner: <cluster-name>` and `powervs.cluster.x-k8s.io/cluster-uuid: UUID` will be added by the controller to newly created cloud resources marking the resource as created by controller.
+ During cluster creation with infrastructure creation if the resources are already present with the same name in the cloud. It will lead to security issues because there is a possibilty the existing resources in the cloud belong to different user. So to handle this scenario this tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` is added. UUID in tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` represents cluster object ID.
+ 
+ During deletion phase the system will look for the presence of both the tags and match inorder to proceed with deletion or to keep as it is. 
+
+ Below are the cluster creation scenarios.
  #### Creating a new cluster 
- - When resources will be created for new cluster in the cloud both the tags will be attached.
+ - When resources will be created for new cluster in the cloud both the tags will be attached. During deletion flow, will check for both tags `powervs.cluster.x-k8s.io/owner: <cluster-name>` and `powervs.cluster.x-k8s.io/cluster-uuid: UUID` and delete the resources.
  #### Creating a new cluster with reusing pre-created resources
- - When cluster is created using existing resources, no tags will be attached.
+ - When cluster is created using existing resources, no tags will be attached. We won't delete these resources, as these were not created by controller.
  #### Creating a new cluster with reusing pre-created resources from old cluster.
- - When creating the resources in the cloud, first will check this tag is matching `powervs.cluster.x-k8s.io/owner: <cluster-name>` since resources already exists with same name but this tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` won't match. So will error out to user that resources with similar name already exist, he has to provide different name to cluster.
+ - When cluster creation is triggered with clustername "test-cluster", resources like "test-cluster-serviceInstance, test-cluster-VPC, test-cluster-loadbalancer, test-cluster-TransitGateway, test-cluster-COSInstance" are created. When creating the resources in the cloud, first will check if this tag is matching `powervs.cluster.x-k8s.io/owner: <cluster-name>` since resources already exists with same name but second tag `powervs.cluster.x-k8s.io/cluster-uuid: UUID` won't match because UUIDs of cluster object will be different. So will error out to user that resources with similar name already exist, user has to provide different name to cluster.
 
 
 #### Following resources will be getting tagged