Submitting Patches

Patches are welcome! We currently use the vanilla GitHub merge workflow, where individual pull requests are merged by a human via the web UI.

During the review, any changes should be made as a new commit or an amended commit. These can be force pushed to your branch and GitHub should be able to show the "interdiff" between pushes.

Commit Message Style

Please look at git log and match the commit log style, which is very similar to the Linux kernel.

You may use Signed-off-by, but we're not requiring it.

General Commit Message Guidelines:

1. Title
   • Specify the context or category of the changes e.g. lib for library changes, docs for document changes, bin/<command-name> for command changes, etc.
   • Begin the title with the first letter of the first word capitalized.
   • Aim for less than 50 characters, otherwise 72 characters max.
   • Do not end the title with a period.
   • Use an imperative tone.
2. Body
   • Separate the body with a blank line after the title.
   • Begin a paragraph with the first letter of the first word capitalized.
   • Each paragraph should be formatted within 72 characters.
   • Content should be about what was changed and why this change was made.
   • If your commit fixes an issue, the commit message should end with Closes: #<number>.

Commit Message example:

<context>: Less than 50 characters for subject title

A paragraph of the body should be within 72 characters.

This paragraph is also less than 72 characters.

For more information see How to Write a Git Commit Message

Editing a Committed Message:

To edit the message from the most recent commit run git commit --amend. To change older commits on the branch use git rebase -i. For a successful rebase, have the branch track upstream main. Once the changes have been made and saved, run git push --force origin <branch-name>.

Testing Changes

At a bare minimum, your changes should pass the tests/check.sh script. This is just some simple syntax checking, but is better than nothing at all.

A more useful test of your changes would include the following:

• local build of coreos-assembler container image
• a build of coreos-assembler container image on Quay.io
• a successful coreos-assembler build && coreos-assembler run of Fedora CoreOS using your changes in a "rootless" configuration (i.e. no use of --privileged)

Code Style

We currently use a mix of bash shell scripts and Python.

The current preference is to use spaces instead of tabs. We require the use of spaces when working with Python (as covered in PEP8). We will tolerate tabs when working with the shell scripts, but we have a strong preference for spaces. In both cases, we most commonly use 4 spaces per indent. Please follow the convention of the file that you are changing and avoid mixing tabs/spaces whenever possible.

Our enforcement of bash style is mostly handled via ShellCheck.

We have a loose of set of guidelines being discussed about what we expect for Python style. The agreed upon items:

• 4 spaces per indent; no tabs
• target Python 3.6
• use os.path.join() when constructing paths
• use flake8 to check any changes to existing Python
• use pylint when introducing any new Python files