Cluster parameter does not respect prefixes

[michaelskahn]

I'm using the prefix option to deploy multiple watchbot services using a single CFN stack. This works fine for most parameters, but trying to set different values for the cluster results in an error:

Error: Outputs name used more than once: ClusterArn

The ClusterArn appears to be treated differently than the other options in that it isn't prefixed, so defining multiple watchbot services in a single template fails unless the cluster is always the same. Is having multiple clusters within a single stack something that watchbot can support?

[rclark]

That should be prefixed. Think you could put together a PR?

[michaelskahn]

Sure. I can (I think) preserve existing behavior by setting an overall ClusterArn if and only if all clusters are the same. That avoids a breaking change for downstream consumers that may be relying on the current ClusterArn output value while setting prefixes.

[rclark]

Hm, I think that the lack of prefixed output here is a straight-up bug. Yes, it'd be a breaking change, but I think it is better to break the bugged behavior and make a new major version release.