Update README.md with explanation of EKS Pod Identity configuration with EFS CSI Controller

[leondkr]

Update Controller Pod Identity config description

Is this a bug fix or adding new feature?

Feature

What is this PR about? / Why do we need it?

Adds more details of integration between EKS Pod Identities feature and k8s service account of EFS CSI controller when the controller wants to communicate with EFS services using sufficient permissions.

What testing is done?

Here is the controller logs when we do not use arn:aws:iam::aws:policy/service-role/AmazonEFSCSIDriverPolicy before and after:

I0801 07:02:02.139270       1 controller.go:335] Using /pvc-a2755de8-c8fb-4ecd-b866-d86a43186784 as the access point directory.
E0801 07:02:02.175852       1 driver.go:107] GRPC error: rpc error: code = Unauthenticated desc = Access Denied. Please ensure you have the right AWS permissions: Access denied
I0801 07:03:50.748840       1 controller.go:328] Using PV name for access point directory.
I0801 07:03:50.748911       1 controller.go:335] Using /pvc-c380cab3-3f23-466b-acc6-4b39fa52fd9b as the access point directory.

Here is the events log of my PVC:

Events:
  Type    Reason                 Age   From                                                                                      Message
  ----    ------                 ----  ----                                                                                      -------
  Normal  ExternalProvisioning   19m   persistentvolume-controller                                                               Waiting for a volume to be created either by the external provisioner 'efs.csi.aws.com' or manually by the system administrator. If volume creation is delayed, please verify that the provisioner is running and correctly registered.
  Normal  Provisioning           19m   efs.csi.aws.com_efs-csi-controller-6b6999698f-bvllr_9bea6a5d-81e3-4e23-9905-b92af19e6e46  External provisioner is provisioning volume for claim "cicd/jenkins"
  Normal  ProvisioningSucceeded  19m   efs.csi.aws.com_efs-csi-controller-6b6999698f-bvllr_9bea6a5d-81e3-4e23-9905-b92af19e6e46  Successfully provisioned volume pvc-c380cab3-3f23-466b-acc6-4b39fa52fd9b

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: leondkr / name: Binh Nguyen (1019dbd)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: leondkr
Once this PR has been reviewed and has the lgtm label, please assign ashley-wenyizha for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

Welcome @leondkr!

It looks like this is your first PR to kubernetes-sigs/aws-efs-csi-driver 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/aws-efs-csi-driver has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @leondkr. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[mskanth972]

Hi @leondkr, thanks for the PR. Can you squash the commits so that I can trigger the tests?

[leondkr]

Hi @leondkr, thanks for the PR. Can you squash the commits so that I can trigger the tests?

Hi @mskanth972, I squashed into a single one. Please check if any further action required. Thanks!