Allow to separate subnets for LBs and nodes

[mikkeloscar]

• Depends on Support separate subnets for LBs and workers cluster-lifecycle-manager#827

Allows to have separate subnets for LBs and for nodes which enables different rules for ingress and egress.

Existing clusters will continue to use the same subnets for both. A migration is needed to split it.

[zalando-robot]

Deployment Checklist

This change falls under our deployment policy. Would you call it low-risk? If so, please check this box:

• This is a low-risk change: a feature change or update behind a feature toggle, a minor change, a bug fix, or a patch. It is unlikely to disrupt services, or can be rolled back very quickly (feature toggle).

💁 If this is not a low-risk change, please confirm all of the following requirements:

• Detailed release notes are provided in this PR’s description.
• Thorough load-testing has been performed (link).
• Technical review: Principal Engineers or Tech Leads have green-lit your changes (link).
• You can enable/disable the change via feature toggles, and have confirmed these toggles work as expected.
• Management approval is given by … (Engineering Manager or above).

👉 Regardless of which boxes you click in this comment, merge/deployment will not be blocked (though it’ll be included in cyber week reporting).

[mikkeloscar]

👍

[demonCoder95]

👍