Add `HeadNode:Iam:S3Access` option to the wizard

[stephenmsachs]

While HeadNode:CustomActions:OnNodeStart:Script can be pointed to an s3 location in the wizard, there is currently no mechanism to add the pre-requisite HeadNode:Iam:S3Access. This results in an error trying to use the s3 location as script. S3Access can be granted by hand in the yaml file, but you need to know a few things about pcluster to know where to add the optiion.

[mendaomn]

Good point, thank you. We'll investigate the issue and see if there's a better approach

[eantonin]

We reproduced the issue and put the feature in our roadmap, cannot give a precise ECD yet

[sean-smith]

Hi Stephen another workaround until we fix the issue is to add the AmazonS3ReadOnlyAccess managed policy to the cluster, this is what we do in the weather workshop. It's allowed without any modification to pcluster manager:

https://weather.hpcworkshops.com/template/cluster-config.yaml

[stephenmsachs]

Yes, thanks Sean. That's what I am doing for now.