Ubuntu has announced “Minimal Ubuntu”, a cut-down server image designed for containerised deployments. The Docker image for Minimal Ubuntu 18.04 is 29MB:

Editors, documentation, locales and other user-oriented features of Ubuntu Server have been removed. What remains are only the vital components of the boot sequence.  Images still contain ssh, apt and snapd so you can connect and install any package you’re missing. The unminimize tool lets you ‘rehydrate’ your image into a familiar Ubuntu server package set, suitable for command line interaction.

says Canonical.

29MB is pretty small; but not as small as Alpine Linux images, commonly used by Docker, which are nearer 5MB. Of course these image sizes soon increase when you add the applications you need.

I pulled Ubuntu 18.04 from Docker Hub and the image size is 31.26MB so this hardly seems a breakthrough.

Canonical quotes Paul Nash, Group Product Manager for Google Cloud Platform, in its press release. The image is being made available initially for Amazon EC2, Google Compute Engine, LXD, and KVM/OpenStack. The kernel has been optimized for each deployment, so the downloadable image is optimized for KVM and slightly different than the AWS or GCP versions.