Thank you for taking the time to contribute to the chisel-releases
project.
We welcome quality external contributions in the form of
Pull Requests or
Issues.
Please note that while we acknowledge that there are many conventions and styles, we must strive for consistency and thus your contributions are expected to match the existing codebase, as described by the following guidelines. Any non-conforming proposals will be subject to immediate rejection.
- Code of Conduct
- Canonical Contributor Licence Agreement
- How to Contribute
- Creating Issues
- Submitting Code
- Slicing Debian Packages
- 1. What package are you slicing?
- 2. Which Ubuntu release(s) are you targeting?
- 3. Does a Slice Definitions File (SDF) exist already for that package?
- 4. What other packages do you need to slice?
- 5. Get familiar with the packages
- 6. Build/edit the Slice Definitions File(s)
- 7. Test your slices before opening a PR
- 8. Open the PR(s)
This project and everyone participating in it must follow a Code of Conduct. By participating, you are expected to uphold this code.
Before creating a pull request you should sign the Canonical contributor license agreement. It is the easiest way for you to give us permission to use your contributions.
This project's issues can be found here. Everyone is welcome to comment and add value to existing issues.
If you spot a problem or have a feature request, and a related issue doesn't exist yet, then you can open a new issue.
Code contributions must be submitted in the form of a Pull Request.
Please format your commits following the conventional commit style.
See below for some examples of commit messages:
feat: add new archive to ubuntu-24.04 release
test: increase the smoke tests' verbosity
fix(pkg-a): add missing file to pkg-a_slice
ci(linter): add CI job for linting YAML files
chore(test): update pip dependencies for tests
docs: add new section 'Foo' to README.md
Other common best practices are:
- separate the commit's message subject from the body with a blank line,
- limit the subject line to 50 characters,
- do not capitalize the subject line,
- do not end the subject line with a period,
- use the imperative mood in the subject line,
- wrap the body at 72 characters,
- use the body to explain what and why (instead of how).
Once you're ready to open a PR, please make sure you abide by the following rules:
- you should be branching off a release branch and not
main
or any other development branch, - use the draft mode if your PR is not yet ready to be reviewed,
- provide good PR descriptions as the project maintainers aren't necessarily familiar with the packages you are slicing,
- provide proof of testing and testing instructions, when applicable, to help speed up the review process,
- if you have inter-dependent PRs, make those dependencies explicit in the PRs' descriptions,
- keep an eye out for CI failures as reviewers will look at your proposal once all checks are green,
- if possible, use "Labels" to help the maintainers navigate and prioritize their reviews,
- do not force push once you already have review comments,
- when needed, update your PR by merging the latest changes from the target branch,
- you can close a review comment if you applied the proposed change. Otherwise, or when in doubt, you should simply reply and let the reviewers resolve it.
Please note that in order to get merged, PRs must first be approved at least by two project maintainers.
If you are slicing Debian packages and thus proposing new slice definitions, make sure you read the following guidelines. They describe the typical process for slicing Debian packages, while also highlighting our expectations with respect to the design of a proper Slice Definitions File.
Pull Requests must be holistic! I.e. you should avoid proposing multiple uncorrelated slice definitions in the same Pull Request.
So step 1 is to find the target Debian package you'll be slicing! This is as
simple as thinking about the corresponding apt install
command. For example,
if your installation command looks like apt install <pkg-a>
, then pkg-a
is
your target Debian package and the one your Pull Request shall propose the
slice definitions for.
If you're slicing pkg-a
for Ubuntu 24.04, then your Pull Request must be
created against this repository's ubuntu-24.04
branch.
Why is this important? To enforce consistency across the different chisel
releases, every slice definition that is proposed for a given chisel release
MUST also be proposed for all newer and still supported chisel releases. For
example, in Dec 2023, if you were proposing new slice definitions for
ubuntu-22.04
, then you had to ensure they also existed (or were being
proposed) for ubuntu-23.04
, ubuntu-23.10
and ubuntu-24.04
, if applicable.
Tip: you can check which Ubuntu releases are still supported via ubuntu-distro-info --supported -r
Check if a YAML file with that package's name exists already under the slices
folder (e.g. slices/pkg-a.yaml
).
If it does, then you'll be editing it. Otherwise, you must create it.
Debian packages can have dependencies, so more often than not, you'll need to slice more than one package.
Start by listing which packages you'll need to slice, and remember to double-check if an SDF already exists for those packages too.
Tip: work your way from your target package (e.g. pkg-a
) to its
dependencies and its dependencies' dependencies...and so on. For example,
pkg-a
may depend on pkg-b
, while the latter may depend on pkg-c
and
pkg-d
. So those will be the packages you must consider for slicing. Here are some useful references from where you can check a package's dependencies:
- run
apt show <pkgName>
; - go to
https://packages.ubuntu.com/<release-adjective>/<pkgName>
While you don't need to be a maintainer or an expert in order to slice a Debian package, you do need to understand the packages' composition and the functionality they offer.
Note that in some occasions, a package might have architecture-specific
contents, which means your slice definitions must include the {arch: <arch>}
content path property.
Tip: the fastest way to check which architectures a package is available
for is to simply look it up at
https://packages.ubuntu.com/<release-adjective>/<pkgName>
.
You need to know the contents of the package in order to define the contents of its slices.
Tip: there are multiple ways to look at a package's contents. Here are a few:
apt download <pkgName>:<arch>; dpkg-deb -c <pkgName>_*<arch>.deb
, or- via
<https://packages.ubuntu.com/<release-adjective>/<arch>/<pkgName>/filelist>
.
The functionally relevant parts of the package's maintainer scripts must be reflected by mutation scripts in your slice definitions.
Tip: the best way to explore a package's maintainer scripts is to extract
control information from its Deb. E.g.
apt download <pkgName>; dpkg-deb -e <pkgName>_.deb control-info
. Make sure
you pay special attention to the preinst
_and postinst
scripts if _ exist.
This is important to know as it will dictate how your slices should be designed. To make slicing a future-proof, sustainable and intuitive experience, we must ensure:
- the slice naming convention is consistent across packages and releases.
E.g. many packages deliver configuration files, and these are commonly
arranged in their own package slice. We must AVOID having different SDFs
defining configuration slices with different names (e.g.
conf
vsconfig
vsconfiguration
...); - the slice name must convey the functionality it delivers! As a rule of
thumb:
- if you're slicing a library package (e.g.
libc6
), it is acceptable to define the slice names after the type of files it delivers. For examplelibs
orconfig
; - if you're slicing an application package, then you should define its
slices based on the functionality they deliver. For example:
- a
core
slice for delivering the minimal amount of contents that make the package functional, or - a
debug
slice for delivering specific libraries or utilities for application debugging, or - a
crypto
slice for adding optional modules for cryptographic services, and so on.
- a
- if you're slicing a library package (e.g.
Tip: here's an example of an SDF whose slice name is driven by the type of content it delivers, and here's another example of an SDF whose slices are designed according to the functionality they deliver
Once you know all the above, you have everything you need to write your own slice definitions. When writing, here are a few best practices we recommend:
- consider readability, so keep a nice and consistent YAML formatting style;
- provide additional information via comments, whether it is to justify a design decision or to help clarify the functionality being delivered by a slice;
- use logical sorting for your slices. Sometimes that will result in an alphabetically ordered SDF, some other times it will result in an SDF where the topmost slices are the most relevant ones;
- do NOT abuse globs! It can be tempting to simply define your slice's
contents with something like
/usr/lib/**
. However, such patterns are too generic and considered a bad practice, as they have the potential to create conflicts between slice definitions files;- Tip: when pondering about the use of a glob, consider the following
list of acceptable usages:
- to abstract the architecture name within the path. E.g.:
/a/*-b/c
instead of/a/x86_64-a/c
; - to simplify application-specific paths. E.g.:
/a/appX/module/**
instead of['/a/appX/module/foo', '/a/appX/module/bar/baz', ...]
; - to deal with upstream version updates. E.g.:
/a/b/lib.so.*
instead of/a/b/lib.so.1
, since an upstream package update could potentially bump this version and break the slice definition.
- to abstract the architecture name within the path. E.g.:
- Tip: when pondering about the use of a glob, consider the following
list of acceptable usages:
Apart from asserting your slice definitions' formatting, you must also test them before opening a Pull Request.
Every Chisel release supports the functional testing for slices via Spread.
We expect tests to be provided for every slice, so please ensure you include those in your PRs.
Here's how you can create and run tests for your slice definitions:
- under
tests/spread/integration/
, make sure at least one folder matching the package name you're slicing, exists, - inside that folder you must create a
task.yaml
file. This is where you'll write all the tests for your slide definitions. Please follow the structure from existing examples, providing at least thesummary
andexecute
fields insidetask.yaml
(for other possible fields, please check the Spread docs),- in
test/spread/lib/
you'll also find a set of helper functions that you can call from within yourtask.yaml
execution script,
- in
- once your test is ready, ensure you have the necessary requirements to run it
locally:
- Docker: you can install it via the Snap Store or by following the official instructions
- Spread: we recommend installing it from source (with
go install github.com/snapcore/spread/cmd/spread@latest
), but there's also a Spread snap - QEMU: if testing for multiple architectures, you'll need to install these
packages:
sudo apt-get install qemu binfmt-support qemu-user-static
- from the repository's root directory, you can now run
spread tests/spread/integration/<pkg>
for running the tests for your package<pkg>
slices, on all architectures. Additionally, you can also:- run
spread
for orchestrating all the tests (not just yours), for all architectures, or - run
spread docker:ubuntu-22.04-amd64
for orchestrating all the tests (not just yours) for amd64 only, or - run
spread docker:ubuntu-22.04-arm64v8:tests/spread/integration/<pkg>
for running only the tests for your package<pkg>
slices, on arm64.
- run
Once you have your new slice definitions and you have tested them, you're ready to propose them upstream. When opening a Pull Request, consider the above Pull Request Etiquette in order to make for a more efficient review process.