Base definition migration guide (December 2025)

The base configuration syntax using os and tag is deprecated.

Deprecated configuration

Previously, the base layer was configured using an os along with a tag, like this:

base:
  os: ubuntu 24.04
  tag: 1.2

New configuration

Now, the base layer is configured using an image along with a config.

base:
  image: ubuntu:24.04
  config: rwx/base 1.1.1

Context on the change

Read the announcement on our blog.