document&minimize network dependencies // create on air-gapped network

**Is your feature request related to a problem? Please describe.**
We have a fairly locked down network, only connections to Azure Services are allowed.
So stuff like the IP lookup:
https://github.com/Azure/sap-automation/blob/267278ecf4d1aa7053b45b2a2468e65db90f3752/deploy/scripts/install_workloadzone.sh#L62-L68
https://github.com/Azure/sap-automation/blob/e5e295566ee97af4fa6cfcace8eea5999aefdf70/deploy/scripts/prepare_region.sh#L70
https://github.com/Azure/sap-automation/blob/267278ecf4d1aa7053b45b2a2468e65db90f3752/deploy/scripts/installer.sh#L140

does not work.

Also the deployer VM being created does not have access to the internet, so it can't download anything via pip for example.

I would like to minimize the dependencies towards the internet and try to operate only with Azure Services reachable. Apart from that for normal installation with internet access I think you should document what resources you actually need as a list of URLs:
http://ipinfo.io
Pip (pypi.python.org, pypi.org, pythonhosted.org)
Terraform (registry.terraform.io, releases.hashicorp.com)
I do not have a complete list yet, those were just the first things I noticed :)

As for an Non-Internet connected (air-gapped) Install:
I think it would be a good idea to have two parts
a) download everything (apart from that which is available directly from Microsoft like OS repos) you need from the internet and put it into a storage account
b) the actual SAP install

Everything in a) you can do on your desktop or on any internet connected machine
Everything in b) will work without internet connection

**Describe alternatives you've considered**
A lot of enterprises may have internal mirrors for pip/... so it may be a good idea to incorporate that possibility.