Cluster-api-provider-aws: Validate AWS tags

[richardcase]

/kind feature

Describe the solution you'd like
When we create resources in AWS we add a number of Tags to the resources. There are certain restrictions on the tags, such as a maximum of 256 characters for a tag value.

There are variouus places in the code where we create these tags, for example:
https://github.com/kubernetes-sigs/cluster-api-provider-aws/blob/d4ade5922e04a2327f4043effd16252126dea223/pkg/cloud/services/ec2/subnets.go#L323
and we should probably validate the tags we want to create.

The details around the limits and requirements can be found in the AWS documentation:
https://docs.aws.amazon.com/general/latest/gr/aws_tagging.html

Environment:

• Cluster-api-provider-aws version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[richardcase]

/help

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[rudoi]

/assign

Will add context here such that this could be good-first-issue.

[detiber]

/milestone v0.5.x
/priority important-longterm

[evalsocket]

@detiber @rudoi Can this assign to me ?

[detiber]

/assign @evalsocket

@evalsocket I believe you should be able to self-assign issues as long as you've commented on the issue (a comment with just /assign on it's own line should be sufficient to meet the requirement and for the bot to do the assignment)

[evalsocket]

@richardcase what should we do if validation failed. Should we skip the tag or through the error?

[richardcase]

I would say throw an error. The reason being that a lot of people rely in tags for assigning costs to different teams and without the lables it will cause headaches.

[fejta-bot]

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[richardcase]

/remove-lifecycle stale