Allow creating default instance role even when no default node group is created

[flostadler]

As part of #1176 we took the decision to not create the default instance role if users disable the default node groups. Our assumption back then was that there's not a substantial need for this role when users opt out of the default node groups.

#1510 has shown that there is indeed users that were relying on this default instance role that was created "by accident". This original change made the upgrade to v3 more painful than necessary for this set of users!

This change introduces a new plain flag createInstanceRole that can be used to opt-into creating the default instance role even when no default node group is needed.

Resolves #1510

[github-actions]

Does the PR have any schema changes?

Looking good! No breaking changes found.
No new resources/functions.

[bob-bins]

Thanks a bunch @flostadler ! One nitpick is that docs/eks-v3-migration.md can be upgraded to mention createInstanceRole. Something like:

Previously the Cluster component created a default node IAM role even if skipDefaultNodeGroup was set to true. This role gets correctly omitted now if you are specifying skipDefaultNodeGroup. If you have skipDefaultNodeGroup set to true and would like to keep the node IAM role through the migration, you may set createInstanceRole to true.

[flostadler]

Thanks a bunch @flostadler ! One nitpick is that docs/eks-v3-migration.md can be upgraded to mention createInstanceRole. Something like:

Previously the Cluster component created a default node IAM role even if skipDefaultNodeGroup was set to true. This role gets correctly omitted now if you are specifying skipDefaultNodeGroup. If you have skipDefaultNodeGroup set to true and would like to keep the node IAM role through the migration, you may set createInstanceRole to true.

Absolutely, I'm already working on the changes to the official docs that get published to https://www.pulumi.com/docs/ and will back-port those to here afterwards!

[pulumi-bot]

This PR has been shipped in release v3.4.0.