Minimal support for containers as first-class resources

Use case: People want to interact with containers instead of VMs. "Launch" a container, get a shell in a container, upload/download data, etc.

VMs are still useful/needed for security isolation, remote access, and data management purposes.

Possible solution: containers can run inside VMs but users don't need to be aware of that. User clicks 'Launch a container', chooses a size, and selects/inputs a Docker/Singularity/etc. image. Behind the scenes, Exosphere creates a VM from a specific image intended specifically for running containers, and launches that container inside that VM (executed using cloud-init).

Entry point of web shell is inside the container, so user clicks one button to get a shell in the container. Add some web GUI-driven uploader/downloader hosted by the VM, and users have a way to get data in and out. Then you basically have a user-friendly way to run scientific containers in the cloud. I'm probably forgetting lots of things but this is a minimal start.