Change modifyVolumeRequestHandlerTimeout to a configurable option

[andrewcharlton]

Is this a bug fix or adding new feature?
New feature

What is this PR about? / Why do we need it?
This PR changes the modifyVolumeRequestHandlerTimeout, which was previously hardcoded to 2 seconds, into an option that the user can specify. If it is not specified, this should be a complete no-op and default to 2 seconds as before.

The modifyVolumeRequestHandlerTimeout determines how long the controller will wait for additional volume modification calls before executing them and modifying the volume. When changing both the size and IOPs/Throughput of a volume simultaneously there are two calls made and they need to be coalesced together within this window for a single call to AWS to be made. We have seen cases where the 2 seconds is not long enough for this to happen, and only a single one of those changes is made so we would like to extend the window for our use case, where it is more important that the change be atomic than it's latency.

Issue discussing this: #1911

What testing is done?

Added unit test for the new option. Updated coalesce tests to ensure they use the value from the option.

We have a fork with a larger timeout window running in our environment successfully.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: andrewcharlton / name: Andrew Charlton (282e868, c968e0d, d3e650a, ea11623)

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[torredil]

/ok-to-test

[adolsalamanca]

Hello folks,
One important thing to note about this change:

it's very important to make sure that both resizer and modifier timeout args are higher than the specified modify-volume-request-handler-timeout, otherwise users might have contex timeout errors on requests from those to gRPC endpoints in csi-controller.

Timeouts both in resizer and modifier are by default 10s.

[github-actions]

Code Coverage Diff

File	Old Coverage	New Coverage	Delta
github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver/driver.go	32.4%	34.7%	2.4
github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver/validation.go	87.2%	87.8%	0.6

[ConnorJC3]

/lgtm

Hello folks,
One important thing to note about this change:

it's very important to make sure that both resizer and modifier timeout args are higher than the specified modify-volume-request-handler-timeout, otherwise users might have contex timeout errors on requests from those to gRPC endpoints in csi-controller.

Timeouts both in resizer and modifier are by default 10s.

Maybe worth adding a comment about this to the code, or to the docs?

[andrewcharlton]

Maybe worth adding a comment about this to the code, or to the docs?

Thanks, I've added a comment in both the docs, and the descriptor for the flag. I added an additional testcase that I'd missed for the flag as well. Hope that's ok!

[torredil]

Thanks @andrewcharlton
/lgtm

[ConnorJC3]

/lgtm
/label tide/merge-method-squash

[AndrewSirenko]

Thanks for this

[torredil]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: torredil

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