Questions[cloud](ubuntu)

I'm thinking of switching my operating system from Windows and I use Google Drive desktop with all of my video work.

I've installed Ubuntu Server 18.04, and instead of the old /etc/network/interfaces, it seems that my network configuration now lives in a series of YAML files in /etc/netplan, of which the only one I actually have is /etc/netplan/50-cloud-init.yaml:

# This file is generated from information provided by
# the datasource.  Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    ethernets:
        ens3:
            addresses: []
            dhcp4: true
            dhcp6: true
            nameservers: {}
            optional: true
        ens4:
            addresses: []
            dhcp4: true
            dhcp6: true
            nameservers: {}
            optional: true
    version: 2

That seems to have been generated by cloud-init, from /etc/cloud/cloud.cfg.d/50-curtin-networking.cfg:

network:
  ethernets:
    ens3:
      addresses: []
      dhcp4: true
      dhcp6: true
      nameservers: {}
      optional: true
    ens4:
      addresses: []
      dhcp4: true
      dhcp6: true
      nameservers: {}
      optional: true
  version: 2

What's the right way to edit this configuration and apply the changes to the running machine? The comment in the Netplan file suggested to me that it's ephemeral and generated on reboot by cloud-init, so I should edit cloud-init's config. But even after editing it and rebooting, I don't see any changes to the Netplan file, and I definitely don't know how to apply the cloud-init config changes manually. And upon reading the comment again, now it seems to me that it's talking about changes not persisting across destruction and recreation of the machine, which would seem to go without saying. So clearly I'm misunderstanding something.

So my question is:

1. Where in the new cloud-init/netplan system am I supposed to be putting manual network configuration?

2. How do I apply changes I make in /etc/netplan?

3. How do I apply changes I make in /etc/cloud/cloud.cfg.d?

I'd like to see how I can get a list of regions from AWS on the command line so I can quickly look things up, how can I do this?

When I want to launch an instance of Ubuntu on EC2, how do I find the right one? There are thousands of public images that have "Ubuntu" in their name. I am only interested in running the Official Ubuntu images. How do I now which AMI is the right one?

At our university, our section had a grant of several old P4 computers. We decided on using them to create a 3x3 grid, which would function as a medium for our off-hand processing work. However, as of now, this is all we have done :

This is a video streaming running in 9 parts using vlc/ssh scripts to manage it.

As of now all the computers are connected to a single network, and managed using ssh key based authentication. I would love to hear some innovative ideas. Some hardware details are provided :

1gb RAM, Intel Pentium 4 2.4 GHz, 40GB HDD running Lucid

Particularly, I was thinking about the 40gb Portion being used as a cloud-based storage space for people. Something along the lines of sparkleshare or Owncloud but they don't seem to offer multiple computer based network. If there is someway to harness the computing ability of this grid, I would also like to hear about it.