Drop all custom docker image requirements

[jvstme]

Current

dstack allows running custom Docker images by specifying them in the image property. However, not all images can be used. These are some of the image requirements:

• The software in the image should allow running as root
• The image should have either apt-get or yum
• The image should have /bin/sh
• etc.

Proposed

Drop all image requirements and support all valid Docker images, including images built FROM scratch.

Implementation notes

The main source of requirements seems to be the installation and configuration of the OpenSSH server. Possible solutions to dropping the requirements related to the OpenSSH server include:

• Shipping a statically-linked OpenSSH server binary that would allow running without root privileges and would not need a package manager for installation.
• Using an alternative SSH server implementation in Go, so that the server could be part of the dstack-runner binary.

[github-actions[bot]]

This issue is stale because it has been open for 30 days with no activity.