Create Packer template for VM

[rin-skylight]

Background

This is the big one! This template file will allow us to generate a VM image that can be successfully deployed to multiple provisioners. This will build off the work in #1.

Action requested

A template file exists and can create a VM with a barebones DIBBs installation.

Acceptance Criteria

• Packer template created.
• Template includes initial setup of Ubuntu Minimal installation (user creation, initial apt update and apt upgrade, install of curl and essential utilities, configuration of firewall, closure of unneeded ports, etc.
• Template installs and configures docker and compose dependencies
• Template pulls dibbs images based on a version specified in the environment variables (this is critical for later use in an automated CI/CD environment, when webhooks will kick off new image generation)
• Template sets dibbs images to automatically start
• Provisioners included for Virtualbox, Proxmox, Azure, AWS, GCP, and potentially VSphere

Additional context

If possible, this should include the completed shell script for #2. If this ticket is actioned first, #2 will need to be updated to include the effort needed to add the update script to the build process, along with testing to ensure that it works in at least the Virtualbox provisioner when built locally.