Ubuntu OCI image configuration¶
The definition of the Ubuntu container image follows the OCI image format specification.
So, as with any other container image, the Ubuntu image includes enough metadata that one can inspect the image without actually running the container.
Layers¶
As explained in Ubuntu OCI container images, the Ubuntu container
images are built from a minimal rootfs tarball that is tailored for container
environments. For each Ubuntu release, you’ll find a corresponding release
branch in Launchpad
(e.g. noble-24.04) with the build recipe and a reference to the respective
architecture-specific rootfs tarballs.
Image index¶
The Ubuntu container image is published with a multi-architecture image index, meaning that there will be a container image digest that will internally resolve to multiple architecture-specific digests.
In other words, when pulling any Ubuntu container image by its OCI tag
(e.g. ubuntu:24.04), your container runtime should automatically find and
pull the right container image for your host’s architecture.
If however, you’d like to pin a specific Ubuntu container architecture, you can
pull the Ubuntu container image by its architecture-specific digest
(e.g. ubuntu@sha256:<arch-specific-digest>).
Image configuration¶
The Ubuntu container images are built and published with the following configurations:
no default OCI entrypoint,
bashis the default OCI command,OCI labels to identify the image name (i.e.
ubuntu) and its release.