[Feature]: Support tag on subnet creation

[alistarle]

Problem to Solve

Currently, there is no way to specify the required tag at subnet creation when creating a cluster. Some tags are required on subnet when using the Outscale CCM to create loadbalancer, in particular:

• kubernetes.io/role/elb
• kubernetes.io/role/internal-elb

https://github.com/outscale/cloud-provider-osc/blob/OSC-MIGRATION/deploy/debug-tree.png

Proposed Solution

Adding a Tag attribute on the subnet (like for the security group) in order to specify which subnet can be used for internal and external load-balancer if using CCM, but a generic tag attribute will allow more use case later.

Additional Context

No response

Environment Details

- Kubernetes version (`kubectl version`):
- OS (`/etc/os-release`):
- Kernel (`uname -a`):
- cluster-api-provider-outscale version:
- cluster-api version:
- Install tools:
- Kubernetes distribution:
- Kubernetes distribution version:

[outscale-rce]

Thanks for the suggestion! 👍
We agree that adding a Tags attribute for subnets would make it easier to support required CCM tags and other future use cases.
We’ll review this for possible inclusion in a future update.

[jfbus]

I thought about this while working on CCM 1.0 in July, and started implementing CCM compatibility using roles.

The plan was to let the user set a services and services.internal role on a subnet. If no such role is found, the CCM would use the subnet with the loadbalancer role (see https://github.com/outscale/cloud-provider-osc/blob/b611e4a1472a81ed2b08c97487d2fefb19b8ce7f/cloud-controller-manager/osc/cloud/loadbalancer.go#L461).

To ensure compatibility with CCM 0.x, CAPOSC would need to set kubernetes.io/role/elb and kubernetes.io/role/internal-elb when finding the corresponding new roles.

[alistarle]

I agree that role can be convenient, but is it future proof if we need to add more tag or if we leave user specify his own tag ?

I see in the ccm code you wrote it looks coherent, so we could implement the role field and the tag field later on if we need it ? (tag is already mandatory in SecurityGroup when you need to tag nodes SG with OscMainSG)

Thanks for the dev ! Will definitely try this asap and close this issue when it's good :)

[jfbus]

We will plan the addition of tags in a future release. We can keep this issue open until it is done.

[jfbus]

@alistarle looking back into this. The OscMainSG tag should not be mandatory, the CCM should be able to target the worker nodes SG based on the role tag.