Feature Request: Disable SSH

[mapk-amazon]

Current

ParallelCluster always deploys the security of the headnode with port 22 open. The default being open for 0.0.0.0/0. Best practises is typically not using SSH at all and instead use SSM or similar.

Feature Description

https://docs.aws.amazon.com/parallelcluster/latest/ug/HeadNode-v3.html#HeadNode-v3-Ssh

Add an optional parameter Enabled to Ssh:

Ssh:
  KeyName: string
  AllowedIps: string
  Enabled: boolean

The default should be true to be compatible with the previous setting. If Enabled is given and has the value false, then KeyName and AllowedIps may not be provided. The security of the head node will not get an entry for SSH.

Current workaround

Use 0.0.0.0/32 as AllowedIps. But it adds to confusion and (potentially) to some security risk.

[hgreebe]

I have add this feature request to our backlog.