Using existings NAT gateways for new shoot cluster

[RandolfWerner]

How to categorize this issue?

/area TODO
/kind enhancement

What would you like to be added:

When creating a new shoot cluster on AWS it is possible to reuse an already existing VPC instead of creating a new one. Unfortunately it is currently not possible to reuse already existung NAT gateways (see https://sap-btp.slack.com/archives/C9CEBQPGE/p1664546064348629). Please add shoot cluster cretaion options allowing to reuse already existing NAT gateways.

Why is this needed:
For multi cluster setups each cluster currently creates its own NAT gateways, which results in creating a lot of unnecessary NAT gateways and correspoding (rare) public IPV4 addresses. In our scenraio we would create up to 24 shoot clusters within a single VPC with up to 4 AZs, resultung in 96 (unnecessary) NAT gateways and corresponding public IP addresses.

[gardener-prow]

@RandolfWerner: The label(s) area/todo cannot be applied, because the repository doesn't have them.

In response to this:

How to categorize this issue?

/area TODO
/kind enhancement

What would you like to be added:

When creating a new shoot cluster on AWS it is possible to reuse an already existing VPC instead of creating a new one. Unfortunately it is currently not possible to reuse already existung NAT gateways (see https://sap-btp.slack.com/archives/C9CEBQPGE/p1664546064348629). Please add shoot cluster cretaion options allowing to reuse already existing NAT gateways.

Why is this needed:
For multi cluster setups each cluster currently creates its own NAT gateways, which results in creating a lot of unnecessary NAT gateways and correspoding (rare) public IPV4 addresses. In our scenraio we would create up to 24 shoot clusters within a single VPC with up to 4 AZs, resultung in 96 (unnecessary) NAT gateways and corresponding public IP addresses.

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[gardener-robot]

@RandolfWerner Label area/todo does not exist.

[gardener-robot]

@rfranzke Label area/todo does not exist.

[ludov04]

👍
On this, default limit of elastic ip is 5 per account, creating this amount of elastic ip seems unnecessary and wasteful when public IPv4 are becoming so rare

[waheedshahani]

This would be a cool feature to have. This can save on many elastic IPs and provides possibility to create multiple clusters in same account without requesting Elastic IP quotas. Saves costs a lot too.

[kon-angelo]

/remove lifecycle/rotten