Gitlab contributions

Overview

All Scenarios OS project handles contributions as merge requests to relevant repositories part of the All Scenarios OS GitLab instance. The flow for handling that is classic: fork-based merge requests. This means that once you have an account, you can fork any repository, create a branch with proposed changes and raise a merge request against the forked repository. More generic information you can find on the Gitlab’s documentation as part of “Merge requests workflow”.

Commit Guidelines

Note

If you are new to git, start by reading the official Getting Started Document.

At its core, contributing to the All Scenarios OS project means wrapping your work as git commits. How we handle this has an impact on rebasing, cherry-picking, back-porting, and ultimately exposing consistent documentation through its logs.

To achieve this, we maintain the following commit guidelines:

  • Each commit should be able to stand by itself providing a building block as part of the MR.

    • A good balance of granularity with scoped commits helps to handle backports (e.g. cherry-picks) and also improves the ability to review smaller chunks of code taking commit by commit.

  • Changes that were added on top of changes introduced in the MR, should be squashed into the initial commit.

    • For example, a MR that introduced a new build system recipe and, as a separate commit, fixed a build error in the initial recipe. The latter commit should be squashed into the initial commit.

    • For example, a MR introducing a new docs chapter and also adding, as a separate commit, some typo fixes. The latter commits should be squashed into the initial commit.

    • There is a small set of exceptions to this rule. All these exceptions gravitate around the case where an MR, even if it provides multiple commits in the same scope (for example, to the same build recipe), each of the commits has a very specific purpose.

      • For example, a line formating change followed by a chapter addition change in the same documentation file.

      • Also, it can be the case of two functional changes that are building blocks in the same scope.

      • Another example where commits are not to be squashed is when having a commit moving the code and a commit modifying the code in the new location.

  • Make sure you clean your code of trailing white spaces/tabs and that each file ends with a new line.

  • Avoid merge commits as part of your MR. Your commits should be rebased on top of the HEAD of the destination branch.

As mentioned above, git log becomes informally part of the documentation of the product. Maintaining consistency in its format and content improves debugging, auditing, and general code browsing. To achieve this, we also require the following commit message guidelines:

  • The subject line (the first line) needs to have the following format: scope: Title limited to 80 characters.

    • Use the imperative mood in the subject line for the title.

    • The scope prefix (including the colon and the following whitespace) is optional but most of the time highly recommended. For example, fixing an issue for a specific build recipe, would use the recipe name as the scope.

    • The title (the part after the scope) starts with a capital letter.

    • The entire subject line shouldn’t exceed 80 characters (same text wrapping rule for the commit body).

  • The commit body separated by an empty line from the subject line.

    • The commit body is optional but highly recommended. Provide a clear, descriptive text block that accounts for all the changes introduced by a specific commit.

    • The commit body must not contain more than 80 characters per line.

  • The commit message will have the commit message trailers separated by a new line from the body.

    • Each commit requires at least a Signed-off-by trailer line. See more as part of the DCO sign-off document.

    • All trailer lines are to be provided as part of the same text block - no empty lines in between the trailers.

Additional commit message notes:

  • Avoid using special characters anywhere in the commit message.

  • Be succinct but descriptive.

  • Have at least one trailer as part of each commit: Signed-off-by.

  • You can automatically let git add the Signed-off-by by taking advantage of its -s argument.

  • Whenever in doubt, check the existing log on the file (<FILE>) you are about to commit changes, using something similar to: git log <FILE>.

Example of a full git message:

busybox: Add missing dependency on virtual/crypt

Since version 1.29.2, the busybox package requires virtual/crypt. Add this
to DEPENDS to make sure the build dependency is satisfied.

Signed-off-by: Joe Developer <joe.developer@example.com>

Contributions to Documentation

In All Scenarios OS, the documentation usually stays with the respective code repositories. This means that contributing to documentation is not in any way different than contributing to code. The processes, contribution guidelines are to remain the same. The only difference is that documentation files are to be released under Creative Commons License version 4.0.

Documentation that doesn’t link directly to one specific repository, is available in the docs repository.

In terms of file format, the project unifies its documentation as ReStructuredText files. A RestructuredText primer is available as part of the Sphinx documentation.

As a rule of thumb, anything that ends up compiled in the project documentation is to maintain the RestructuredText file format. Text files that are not meant to be compiled as part of the project’s documentation can be written in Markdown. For example, a repository README file can be written in Markdown as it doesn’t end up compiled in the project-wide documentation.