Add command line arguments to configure leader election options

[RaunakShah]

What type of PR is this?

/kind feature

What this PR does / why we need it:
This PR adds command line arguments for leader election options - Lease Duration, Renew Deadline and Retry Period. Currently the defaults are 15, 10 and 5 seconds respectively. Without this change, there's no way for a customer/storage plugin to configure those values.

This PR makes those parameters configurable. Storage plugins deploying external-provisioner can tune those parameters in their YAMLs accordingly.

Which issue(s) this PR fixes:

Fixes #556

Special notes for your reviewer:

Testing:

Created Provisioner with new arguments and verified that Pod is running:

# cat vsphere-csi-driver.yaml
...
        - name: csi-provisioner
          args:
            - "--v=4"
            - "--timeout=300s"
            - "--csi-address=$(ADDRESS)"
            - "--kube-api-qps=100"
            - "--kube-api-burst=100"
            - "--leader-election"
            - "--default-fstype=ext4"
            - "leader-election-lease-duration=30"
            - "leader-election-renew-deadline=20"
            - "leader-election-retry-period=10"
...
# kubectl get pod -n vmware-system-csi
NAME                                      READY   STATUS    RESTARTS   AGE
vsphere-csi-controller-74f57f8754-x2bcj   6/6     Running   0          21m

Does this PR introduce a user-facing change?:

Add command line arguments to configure leader election options

[ggriffiths]

Looks good once the go fmt issue is fixed

[ggriffiths]

/lgtm

[ggriffiths]

It might be good to make these changes in the other sidecars too so the leader election options stay in sync.

/assign @xing-yang for approver

[RaunakShah]

@ggriffiths yup thats the plan! Thanks for the quick review!

[ggriffiths]

/assign @xing-yang

[xing-yang]

Should there be "--" in front of these new options?

...
        - name: csi-provisioner
          args:
            - "--v=4"
            - "--timeout=300s"
            - "--csi-address=$(ADDRESS)"
            - "--kube-api-qps=100"
            - "--kube-api-burst=100"
            - "--leader-election"
            - "--default-fstype=ext4"
            - "leader-election-lease-duration=30"
            - "leader-election-renew-deadline=20"
            - "leader-election-retry-period=10"
...

[xing-yang]

there's no way for a customer/storage plugin to configure those values.

My understanding is that these are tunable options when starting the external-provisioner so whoever deploys the CSI driver can configure them?

[RaunakShah]

@xing-yang

Should there be "--" in front of these new options?

Fixed the description! And redeployed with the --.

My understanding is that these are tunable options when starting the external-provisioner so whoever deploys the CSI driver can configure them?

That's correct, they can be set before creating the pod. I've also added the parameters to the documentation page.

[xing-yang]

@RaunakShah, I see the following in PR description:

This PR adds command line arguments for leader election options - Lease Duration, Renew Deadline and Retry Period. Currently the defaults are 15, 10 and 5 seconds respectively and there's no way for a customer/storage plugin to configure those values.

If these options are tunable, why you said "there's no way for a customer/storage plugin to configure those values"? Do you mean, without this change, they can't be configured; but with this change, they are tunable? Maybe separate "the current situation" and "with this change" into two paragraphs?

[RaunakShah]

Do you mean, without this change, they can't be configured; but with this change, they are tunable?

@xing-yang This is correct, apologies for the confusion. I've updated the PR description with more clarity!

[xing-yang]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RaunakShah, xing-yang

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[jingxu97]

@RaunakShah Thanks for the PR. Do you mind making the similar changes to other csi sidecars? Thanks!