Ubuntu image builder

This tool is used to build Ubuntu images. Currently builds Ubuntu Core snap-based images from model assertions and Ubuntu classic preinstalled images using image definition files, but it will be generalized to build more (eventually all) Ubuntu images.

Requirements

Ubuntu 18.04 (Bionic Beaver) is the minimum platform requirement, but Ubuntu 20.04 (Focal Fossa) or newer is recommended. All required third party packages are available in the Ubuntu archive.

If you want to run the test suite locally, you should install all the build dependencies named in the debian/control file. The easiest way to do that is to run::

$ sudo apt build-dep ./

from the directory containing the debian subdirectory. Alternatively of course, you can just install the packages named in the Build-Depends field.

Project details

• Project home: https://github.com/Canonical/ubuntu-image
• Report bugs at: https://bugs.launchpad.net/ubuntu-image
• Git clone: https://github.com/Canonical/ubuntu-image.git
• Manual page: man ubuntu-image (https://github.com/Canonical/ubuntu-image/blob/main/ubuntu-image.rst)

The "gadget.yaml" specification has moved to the snapcraft forum

Build Instructions

• Ensure golang >= 1.21 is installed
• Clone the git repository using git clone https://github.com/canonical/ubuntu-image.git
• cd into the newly cloned repository
• Run go build -o . ./...
• The newly compiled executable ubuntu-image will be created in the current directory

Release process

ubuntu-image is released as a snap on the snapstore.

When changes are merged in main, a new snap is automatically built and pushed to the latest/edge channel.

When we think we have a "stable enough" version that we don't want to break with future merges in main, we want to promote it to latest/candidate. To do so:

• create a new branch
• update the version in snapcraft.yaml, copyrights, changelog, etc.
• commit, tag X.Y and push
• merge
• let it build and appear in latest/edge
• promote it to latest/candidate

After a couple of weeks, if our "early adopters" are happy and we did not break any build or if we did not spot any major fix to do, promote this version from latest/candidate to latest/stable.

This way, our users can choose between:

• the latest/edge channel updated as soon as we merge changes.
• the latest/candidate channel with new features / bug fix but with potentially some newly introduced bug. This channel would be good to let users test requested features.
• the latest/stable channel that should hopefully contain a rather "bug free" version because it was tested in more various situations.