fix: safely reset k8s without breaking SSH connection 🐛

[venom90]

/kind bug

What this PR does / why we need it:
This PR modifies the reset.yml task to preserve SSH connectivity during iptables cleanup operations. Currently, when the reset task flushes iptables rules, it can terminate the admin's SSH session, making the server inaccessible and leaving the reset process in an incomplete state.

The modifications:

• Set iptables default policies to ACCEPT before modifications
• Add explicit rules to preserve SSH port connectivity
• Selectively remove Kubernetes-related iptables chains instead of flushing all rules
• Use a deferred reboot with a delay to allow SSH sessions to disconnect gracefully

Which issue(s) this PR fixes:
NA

Special notes for your reviewer:
This is a common operational problem when administrators run reset.yml and suddenly lose access to their servers. The change has been tested on multiple environments to ensure it preserves connectivity while still thoroughly cleaning up Kubernetes components.

Does this PR introduce a user-facing change?:

Modified reset.yml to preserve SSH connectivity during cluster reset operations, preventing administrators from losing access to servers when iptables rules are cleaned up.

[k8s-ci-robot]

Adding the "do-not-merge/release-note-label-needed" label because no release-note block was detected, please follow our release note process to remove it.

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[linux-foundation-easycla]

• ✅login: venom90 / (68300f7)

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: venom90
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[k8s-ci-robot]

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[k8s-ci-robot]

Hi @venom90. 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.

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[VannTen]

/ok-to-test Please drop the whitespace only changes though.

[venom90]

/ok-to-test Please drop the whitespace only changes though.

The YAML formatter removed the extra spaces, didn't added any.

[VannTen]

The YAML formatter remove the extra spaces, didn't added any.

Hum, this does not happen when I ran pre-commit run, and the version are fixed in the config file so I'm not sure how that would happen. Regardless, please drop them.

[VannTen]

Regarding the content, why the need for for shell that way ?
Doesnt meta: reset_connection` would work to force establish a new ssh session instead ?

[VannTen]

The modifications:

• Set iptables default policies to ACCEPT before modifications
• Add explicit rules to preserve SSH port connectivity
• Selectively remove Kubernetes-related iptables chains instead of flushing all rules
• Use a deferred reboot with a delay to allow SSH sessions to disconnect gracefully

You're not actually doing that expect the third item, maybe you forgot to commit ?

[venom90]

The modifications:

• Set iptables default policies to ACCEPT before modifications
• Add explicit rules to preserve SSH port connectivity
• Selectively remove Kubernetes-related iptables chains instead of flushing all rules
• Use a deferred reboot with a delay to allow SSH sessions to disconnect gracefully

You're not actually doing that expect the third item, maybe you forgot to commit ?

Okay, I'll check and re-commit. Thanks.

[venom90]

The YAML formatter remove the extra spaces, didn't added any.
Hum, this does not happen when I ran pre-commit run, and the version are fixed in the config file so I'm not sure how that would happen. Regardless, please drop them.

Okay, let me fix it.