This document briefly describes how to contribute to the BioContainers project.

Before you Begin

If you have an idea for a feature/container to add or an approach for a bugfix, it is best to communicate with BioContainers developers early. The most common venues for this are GitHub issues for common specification issues and the Containers and Tools for container/docker related issues. Browse through existing GitHub issues and if one seems related, comment on it. If no existing issue seems appropriate, a new issue can be opened using this form. BioContainers developers are also generally available via Gitter

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How to Contribute

  • All changes to the specifications BioContainers project should be made through pull requests to this repository (with just two exceptions outlined below).
  • If you are new to Git, the Try Git tutorial is a good places to start. More learning resources are listed at .
  • Make sure you have a free GitHub account.
  • Fork the container repository on GitHub to make your changes. (While many Containers instances track active development happens in the containers GitHub repository and this is where pull requests should be made).
  • Choose the correct branch to develop your changes against.
    • Additions of new features to the code base should be pushed to the dev branch (git checkout dev).
    • Most bug fixes to previously release components (things in bidocker-dist) should be made against the recent release_XX.XX branch (git checkout release_XX.XX).
    • Serious security problems should not be fixed via pull request - please responsibly disclose these by e-mailing them (with or without patches) to . The BioContainers core development team will solve those issues and we will provide you credit for the discovery when publicly disclosing the issue.
  • If your changes modify containers/images - please ensure the resulting files conform to BioContainers Specifications BioContainers Specifications.
  • Commit and push your changes to your fork.
  • Open a pull request with these changes. You pull request message ideally should include:
    • A description of why the changes should be made.
    • A description of the implementation of the changes.
    • A description of how to test the changes.
  • The pull request should pass all the continuous integration tests which are automatically run by GitHub using e.g. Travis CI.


BioContainers’s BioContainers Specification and Design is filled with comments and ideas for enhancements and we believe would make the best entry points for new developers.

A Quick Note about Containers

For the most part, BioContainers containers should be published to the BioContainers containers and not in this repository directly. If you are looking to supply new containers first check if an existing container exists in this repository BioContainers containers - please checkout the repository on GitHub.

Handling Pull Requests

Everyone is encouraged to express opinions and issue non-binding votes on pull requests, but only members of the contributors group may issue binding votes on pull requests.

Votes on pull requests should take the form of +1, 0, -1, and fractions as outlined by the Apache Foundation.

Pull requests modifying pre-existing releases should be restricted to bug fixes and require at least 2 +1 binding votes from someone other than the author of the pull request with no -1 binding votes.

Pull requests changing or clarifying the procedures governing this repository:

  • Must be made to the dev branch of this repository.
  • Must remain open for at least 192 hours (unless every qualified committer has voted).
  • Require binding +1 votes from at least 25% of qualified committers with no -1 binding votes.
  • Should be titled with the prefix [PROCEDURES] and tagged with the procedures tag in Github.
  • Should not be modified once open. If changes are needed, the pull request should be closed, re-opened with modifications, and votes reset.
  • Should be restricted to just modifying the procedures and generally should not contain code modifications.
  • If the pull request adds or removes committers, there must be a separate pull request for each person added or removed.

Any other pull request requires at least 1 +1 binding vote from someone other than the author of the pull request. A member of the committers group merging a pull request is considered an implicit +1.

Pull requests marked [WIP] (i.e. work in progress) in the title by the author(s), or tagged WIP via GitHub tags, may not be merged without coordinating the removal of that tag with the pull request author(s), and completing the removal of that tag from wherever it is present in the open pull request.


Except in the case of pull requests modifying governance procedures, there are generally no objective guidelines defining how long pull requests must remain open for comment. Subjectively speaking though - larger and more potentially controversial pull requests containing enhancements should remain open for a at least a few days to give everyone the opportunity to weigh in.


A note on vetoes (-1 votes) taken verbatim from the Apache Foundation:

“A code-modification proposal may be stopped dead in its tracks by a -1 vote by a qualified voter. This constitutes a veto, and it cannot be overruled nor overridden by anyone. Vetoes stand until and unless withdrawn by their casters.

To prevent vetoes from being used capriciously, they must be accompanied by a technical justification showing why the change is bad (opens a security exposure, negatively affects performance, etc. ). A veto without a justification is invalid and has no weight.”

For votes regarding non-coding issues such as procedure changes, the requirement that a veto is accompanied by a technical justification is relaxed somewhat, though a well reasoned justification must still be included.


A -1 vote on any recently merged pull request requires an immediate reversion of the merged pull request. The backout of such a pull request invokes a mandatory, minimum 72 hour, review period.

  • Recently merged pull requests are defined as a being within the past 168 hours (7 days), so as to not prevent forward progress, while allowing for reversions of things merged without proper review and consensus.
  • The person issuing the -1 vote will, upon commenting -1 with technical justification per the vetoes section, immediately open a pull request to revert the original merge in question. If any committer other than the -1 issuer deems the justification technical - regardless of whether they agree with justification - that committer must then merge the pull request to revert.

Direct Commit Access

The BioContainers committers group may only commit directly to BioContainers (i.e. outside of a pull request and not following the procedures described here) the following two categories of patches:

  • Patches for serious security vulnerabilities.
  • Cherry-picking and/or merging of existing approved commits to other branches.