docs: update Storage Class documentation

README.md

@@ -38,23 +38,34 @@ To disable of creation IRSA role and IRSA policy, set `irsa_role_create = false`
 
 ## Storage Class
 
-Creation of defined Storage Classes is enabled by default. Set `storage_classes_create = false` to disable it.
+Default StorageClass is enabled by default with following definition:
+
+    {
+      "name" : "ebs-csi-gp3"
+      "annotations" : {
+        "storageclass.kubernetes.io/is-default-class" : "true"
+      }
+      "allowVolumeExpansion" : true
+      "volumeBindingMode" : "WaitForFirstConsumer"
+      "reclaimPolicy" : "Delete"
+      "parameters" : {
+        "type" : "gp3"
+        "encrypted" : "true"
+      }
+    }
+
+To override default module StorageClass behaviour use variable `storage_classes`. Provisioner attribute is hardcoded in [EBS-CSI-driver chart](https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/charts/aws-ebs-csi-driver/templates/storageclass.yaml) and cannot be changed. For other parameters attributes please see [EBS-CSI Storage Class parameters](https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/docs/parameters.md).
 
-One Storage Class is defined by default:
-
-https://github.com/lablabs/terraform-aws-eks-ebs-csi-driver/blob/b5c05b76e2664dc235130791a958ab0409f84837/variables.tf#L111-L128
+### Potential issues after enabling StorageClass creation
 
-To extend or modify this definition use variable `storage_classes`.
-`provisioner` attribute of defined Storage Classes will be set to `ebs.csi.aws.com` ([EBS-CSI-driver chart](https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/charts/aws-ebs-csi-driver/templates/storageclass.yaml)). To define other Storage Class parameters use [EBS-CSI Storage Class parameters](https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/docs/parameters.md)
+With each new cluster, Amazon EKS applies a `kubernetes.io/aws-ebs` based StorageClass named `gp2` with defined `“storageclass.kubernetes.io/is-default-class” : “true”` and by default module also creates StorageClass which contains same `storageclass.kubernetes.io/is-default-class` annotations. This may lead to errors while creating Persistent Volume Claim objects without specifying StorageClass name as described in the [documentation](https://kubernetes.io/docs/tasks/administer-cluster/change-default-storage-class/#changing-the-default-storageclass).
 
-### Potential issues after enabling StorageClass creation
-`gp2` Storage Class is created along with EKS cluster creation and it is annotated as [default Storage Class](https://docs.aws.amazon.com/eks/latest/userguide/storage-classes.html).
-Default configuration of Storage Class in this module contains annotation `"storageclass.kubernetes.io/is-default-class" : "true"`, so an error may occur while creating Persistent Volume Claim objects without specifying Storage Class name, because of more than 1 Storage Classes are annotated as default.
+There are several ways to prevent this error:
+1. delete EKS default StorageClass gp2 before PVC usage
+2. change annotation on EKS default storage class
+3. disable or modify default module StorageClass definition
 
-To prevent this error:
 
-1. [change annotation on gp2 Storage Class](https://kubernetes.io/docs/tasks/administer-cluster/change-default-storage-class/#changing-the-default-storageclass) or
-2. modify `storage_classes` to not annotate Storage Classes as default