## Developer Certificate of Origin + License

By contributing to GitLab B.V., You accept and agree to the following terms and
conditions for Your present and future Contributions submitted to GitLab B.V.
Except for the license granted herein to GitLab B.V. and recipients of software
distributed by GitLab B.V., You reserve all right, title, and interest in and to
Your Contributions. All Contributions are subject to the following DCO + License
terms.

[DCO + License](https://gitlab.com/gitlab-org/dco/blob/master/README.md)

All Documentation content that resides under the [docs/ directory](/docs) of this
repository is licensed under Creative Commons:
[CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).

_This notice should stay as the first item in the CONTRIBUTING.md file._

---

## Contribute to GitLab Runner

The following contents has to be considered as an extension over [gitlab-ce contributing guidelines](https://docs.gitlab.com/ce/development/contributing/index.html).

### How we prioritize MRs from the wider community

Currently we use a system of [scoped labels](https://docs.gitlab.com/ee/user/project/labels.html#scoped-labels-premium) to help us prioritize which MRs our team will review. 

| Label | Meaning | Use Cases |
| ---- | ----- | ----- |
| ~"Review::P1" | Highest priority to review | Indicates an MR that might solve an urgent pain point for users, contributes to the strategic direction of the runner development as laid out by the Product team, or fixes a critical issue. We maintain a hard cap on the number of contributions marked ~"Review::P1" at which is currently set at 3. |
| ~"Review::P2" | Default priority to review | All incoming MRs should default to this. |
| ~"Review::P3" | Lowest priority to review | WIP MRs, feature enhancements that only appear to serve a small number of users. |

### Contributing new [executors](https://docs.gitlab.com/runner/#selecting-the-executor)

We are no longer accepting or developing new executors for a few
reasons listed below:

- Some executors require licensed software or hardware that GitLab Inc.
  doesn't have.
- Each new executor brings its own set of problems when it comes to
  testing it properly.
- Adding new executors can add new dependencies, which adds maintenance costs.
- Having a lot of executors adds to maintenance costs.

With GitLab 12.1, we introduced the [custom
executor](https://gitlab.com/gitlab-org/gitlab-runner/issues/2885),
which will provide a way to create an executor of choice.

### Contributing new hardware architectures

We're currently exploring how we can add builds for new and different hardware
architectures. Adding and supporting new architectures brings added levels of 
complexity and may require hardware that GitLab Inc. doesn't have access to.

At the current time, new hardware architectures will only be considered if the 
following criteria are met:

1. GitLab Inc. must be able to build and test for the new architecture on our Shared Runners on GitLab.com
1. If adding support for the new architecture in the helper image, Docker must also support the architecture upstream

As we explore adding more architectures other requirements may come up.

We are currently discussing the ability of providing builds for architectures that we
don't have the ability to support and [we welcome contributions to that discussion](https://gitlab.com/gitlab-org/gitlab-runner/issues/4229).

## Workflow labels

We have some additional labels plus those defined in [gitlab-ce workflow labels](https://docs.gitlab.com/ce/development/contributing/issue_workflow.html)

- Additional subjects: ~cache, ~executors, ~"git operations"
- OS: ~"os::Linux" ~"os::MacOSX" ~"os:FreeBSD" ~"os::Windows" 
- executor: ~"executor::docker" ~"executor::kubernetes" ~"executor::docker\-machine" ~"executor::docker\-machine" ~"executor::shell" ~"executor::parallels" ~"executor::virtualbox"