Don't change the permissions of the bastion private key file generated by terraform

[edisongustavo]

The permissions of the terraform generated file is changed here:

chmod 400 $bastion_pem_filename

Which can lead to problems if terraform ever wants to write to the file again:

Error: Error applying plan:

1 error(s) occurred:

* local_file.bastion_privatekey_pem: 1 error(s) occurred:

* local_file.bastion_privatekey_pem: open bastion_private.pem: permission denied

In my case it didn't want to change the contents of the file, but terraform was failing anyway.

I believe we can trust terraform to do the right thing, ie, if it wants to change the contents of the file, then it will re-recreate the bastion instance.

Places that need changing

This file is required to run commands against the bastion (eg.: baictl get benchmark).

These commands should be updated to deal with this situation.

[edisongustavo]

PR #83 moves the permissions change inside Terraform, however, I don't believe that this is enough.

This depends on hashicorp/terraform-provider-local#19 to be solved.