# Contributing to Docker Want to hack on Docker? Awesome! Here are instructions to get you started. They are probably not perfect, please let us know if anything feels wrong or incomplete. ## Topics * [Security Reports](#security-reports) * [Design and Cleanup Proposals](#design-and-cleanup-proposals) * [Reporting Issues](#reporting-issues) * [Build Environment](#build-environment) * [Contribution Guidelines](#contribution-guidelines) * [Community Guidelines](#docker-community-guidelines) ## Security Reports Please **DO NOT** file an issue for security related issues. Please send your reports to [security@docker.com](mailto:security@docker.com) instead. ## Design and Cleanup Proposals When considering a design proposal, we are looking for: * A description of the problem this design proposal solves * A pull request, not an issue, that modifies the documentation describing the feature you are proposing, adding new documentation if necessary. * Please prefix your issue with `Proposal:` in the title * Please review [the existing Proposals](https://github.com/docker/docker/pulls?q=is%3Aopen+is%3Apr+label%3AProposal) before reporting a new one. You can always pair with someone if you both have the same idea. When considering a cleanup task, we are looking for: * A description of the refactors made * Please note any logic changes if necessary * A pull request with the code * Please prefix your PR's title with `Cleanup:` so we can quickly address it. * Your pull request must remain up to date with master, so rebase as necessary. ## Reporting Issues When reporting [issues](https://github.com/docker/docker/issues) on GitHub please include your host OS (Ubuntu 12.04, Fedora 19, etc). Please include: * The output of `uname -a`. * The output of `docker version`. * The output of `docker -D info`. Please also include the steps required to reproduce the problem if possible and applicable. This information will help us review and fix your issue faster. ## Build Environment For instructions on setting up your development environment, please see our dedicated [dev environment setup docs](http://docs.docker.com/contributing/devenvironment/). ## Contribution guidelines ### Pull requests are always welcome We are always thrilled to receive pull requests, and do our best to process them as quickly as possible. Not sure if that typo is worth a pull request? Do it! We will appreciate it. If your pull request is not accepted on the first try, don't be discouraged! If there's a problem with the implementation, hopefully you received feedback on what to improve. We're trying very hard to keep Docker lean and focused. We don't want it to do everything for everybody. This means that we might decide against incorporating a new feature. However, there might be a way to implement that feature *on top of* Docker. ### Discuss your design on the mailing list We recommend discussing your plans [on the mailing list](https://groups.google.com/forum/?fromgroups#!forum/docker-dev) before starting to code - especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give feedback on your design, and maybe point out if someone else is working on the same thing. ### Create issues... Any significant improvement should be documented as [a GitHub issue](https://github.com/docker/docker/issues) before anybody starts working on it. ### ...but check for existing issues first! Please take a moment to check that an issue doesn't already exist documenting your bug report or improvement proposal. If it does, it never hurts to add a quick "+1" or "I have this problem too". This will help prioritize the most common problems and requests. ### Conventions Fork the repository and make changes on your fork in a feature branch: - If it's a bug fix branch, name it XXXX-something where XXXX is the number of the issue. - If it's a feature branch, create an enhancement issue to announce your intentions, and name it XXXX-something where XXXX is the number of the issue. Submit unit tests for your changes. Go has a great test framework built in; use it! Take a look at existing tests for inspiration. Run the full test suite on your branch before submitting a pull request. Update the documentation when creating or modifying features. Test your documentation changes for clarity, concision, and correctness, as well as a clean documentation build. See `docs/README.md` for more information on building the docs and how they get released. Write clean code. Universally formatted code promotes ease of writing, reading, and maintenance. Always run `gofmt -s -w file.go` on each changed file before committing your changes. Most editors have plug-ins that do this automatically. Pull requests descriptions should be as clear as possible and include a reference to all the issues that they address. Commit messages must start with a capitalized and short summary (max. 50 chars) written in the imperative, followed by an optional, more detailed explanatory text which is separated from the summary by an empty line. Code review comments may be added to your pull request. Discuss, then make the suggested modifications and push additional commits to your feature branch. Be sure to post a comment after pushing. The new commits will show up in the pull request automatically, but the reviewers will not be notified unless you comment. Pull requests must be cleanly rebased ontop of master without multiple branches mixed into the PR. **Git tip**: If your PR no longer merges cleanly, use `rebase master` in your feature branch to update your pull request rather than `merge master`. Before the pull request is merged, make sure that you squash your commits into logical units of work using `git rebase -i` and `git push -f`. After every commit the test suite should be passing. Include documentation changes in the same commit so that a revert would remove all traces of the feature or fix. Commits that fix or close an issue should include a reference like `Closes #XXXX` or `Fixes #XXXX`, which will automatically close the issue when merged. Please do not add yourself to the `AUTHORS` file, as it is regenerated regularly from the Git history. ### Merge approval Docker maintainers use LGTM (Looks Good To Me) in comments on the code review to indicate acceptance. A change requires LGTMs from an absolute majority of the maintainers of each component affected. For example, if a change affects `docs/` and `registry/`, it needs an absolute majority from the maintainers of `docs/` AND, separately, an absolute majority of the maintainers of `registry/`. For more details see [MAINTAINERS.md](hack/MAINTAINERS.md) ### Sign your work The sign-off is a simple line at the end of the explanation for the patch, which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple: if you can certify the below (from [developercertificate.org](http://developercertificate.org/)): ``` Developer Certificate of Origin Version 1.1 Copyright (C) 2004, 2006 The Linux Foundation and its contributors. 660 York Street, Suite 102, San Francisco, CA 94110 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Developer's Certificate of Origin 1.1 By making a contribution to this project, I certify that: (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it. (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved. ``` Then you just add a line to every git commit message: Signed-off-by: Joe Smith Using your real name (sorry, no pseudonyms or anonymous contributions.) If you set your `user.name` and `user.email` git configs, you can sign your commit automatically with `git commit -s`. Note that the old-style `Docker-DCO-1.1-Signed-off-by: ...` format is still accepted, so there is no need to update outstanding pull requests to the new format right away, but please do adjust your processes for future contributions. #### Small patch exception There are several exceptions to the signing requirement. Currently these are: * Your patch fixes spelling or grammar errors. * Your patch is a single line change to documentation contained in the `docs` directory. * Your patch fixes Markdown formatting or syntax errors in the documentation contained in the `docs` directory. If you have any questions, please refer to the FAQ in the [docs](http://docs.docker.com) ### How can I become a maintainer? * Step 1: Learn the component inside out * Step 2: Make yourself useful by contributing code, bug fixes, support etc. * Step 3: Volunteer on the IRC channel (#docker at Freenode) * Step 4: Propose yourself at a scheduled docker meeting in #docker-dev Don't forget: being a maintainer is a time investment. Make sure you will have time to make yourself available. You don't have to be a maintainer to make a difference on the project! ### IRC Meetings There are two monthly meetings taking place on #docker-dev IRC to accomodate all timezones. Anybody can ask for a topic to be discussed prior to the meeting. If you feel the conversation is going off-topic, feel free to point it out. For the exact dates and times, have a look at [the irc-minutes repo](https://github.com/docker/irc-minutes). They also contain all the notes from previous meetings. ## Docker Community Guidelines We want to keep the Docker community awesome, growing and collaborative. We need your help to keep it that way. To help with this we've come up with some general guidelines for the community as a whole: * Be nice: Be courteous, respectful and polite to fellow community members: no regional, racial, gender, or other abuse will be tolerated. We like nice people way better than mean ones! * Encourage diversity and participation: Make everyone in our community feel welcome, regardless of their background and the extent of their contributions, and do everything possible to encourage participation in our community. * Keep it legal: Basically, don't get us in trouble. Share only content that you own, do not share private or sensitive information, and don't break the law. * Stay on topic: Make sure that you are posting to the correct channel and avoid off-topic discussions. Remember when you update an issue or respond to an email you are potentially sending to a large number of people. Please consider this before you update. Also remember that nobody likes spam. ### Guideline Violations — 3 Strikes Method The point of this section is not to find opportunities to punish people, but we do need a fair way to deal with people who are making our community suck. 1. First occurrence: We'll give you a friendly, but public reminder that the behavior is inappropriate according to our guidelines. 2. Second occurrence: We will send you a private message with a warning that any additional violations will result in removal from the community. 3. Third occurrence: Depending on the violation, we may need to delete or ban your account. **Notes:** * Obvious spammers are banned on first occurrence. If we don't do this, we'll have spam all over the place. * Violations are forgiven after 6 months of good behavior, and we won't hold a grudge. * People who commit minor infractions will get some education, rather than hammering them in the 3 strikes process. * The rules apply equally to everyone in the community, no matter how much you've contributed. * Extreme violations of a threatening, abusive, destructive or illegal nature will be addressed immediately and are not subject to 3 strikes or forgiveness. * Contact abuse@docker.com to report abuse or appeal violations. In the case of appeals, we know that mistakes happen, and we'll work with you to come up with a fair solution if there has been a misunderstanding.