5.2. Contributing Changes to RackHD

5.2.1. Guidelines for merging pull requests

For code changes, we currently use a guideline of lazy consensus with two positive reviews with at least one of those reviews being one of the core maintainers and no negative votes. And of course, the gates for the pull requests must pass as well (unit tests, etc).

If you put a review up, please be explicit with a vote (+1, -1, or +/-0) so we can distinguish questions asking for information or background from reviews implying that the relevant change should not be merged. Likewise if you put up a change for review as a pull request, a -1 review comment isn’t a reflection on you as a person, instead is a request to make a modification before that pull request should be merged.

For those with commit privileges

See https://github.com/RackHD/RackHD/wiki/Merge-Guidelines for more informal guidelines and rules of thumb to follow when making merge decisions.

5.2.2. Getting commit privileges

The core committer team will grant contributor rights to the RackHD project using a lazy consensus mechanism. Any of the maintainers/core contributors can nominate someone to have those privileges, and with two +1 votes and no negative votes, the team will grant commit privileges.

The core team will also be responsible for removing commit privileges when appropriate - for example for malicious merge behavior or just inactivity over an extended period of time.

5.2.3. Quality gates for the pull requests

There are three quality gates to ensure the pull requests quality, Hound for code style check, Travis CI for unit-test and coveralls, Jenkins for the combination test including unit-test and smoke test. When a pull request is created, all tests will run automatically, and the test results can be found in the merge status field of each pull request page. Running unit/functional tests locally prior to creating a pull request is strongly encouraged. This would hopefully minimize the amount errors seen during PR submission and lessen a dependency on Travis/Jenkins to test code before it’s really ready to be submitted.


Hound works with jshint and comments on style violations in pull requests. Configuration files .hound.yml and .jshintrc have been created in each repository, so before creating a pull request, you can check code style locally with jshint to find out style violations beforehand.

Travis CI

Travis CI runs the unit tests, and then does some potentially ancillary actions. The build specifics are detailed in the .travis.yml file within each repository. For finding out basic errors before creating a pull request, you can run unit test locally using npm test within each repository.


RackHD uses Concourse CI to monitor and perform quality gate tests on all pull requests prior to merge. The gates include running all the unit tests, running all dependent project unit tests with the code proposed from the pull request, running an integration “smoke test” to verify basic end to end functionality and commenting on the details of test case failure. Concourse can also take instructions from pull request comments or description in order to handle more complex test scenarios. Instructions can be written in the pull request description or comments.

All pull requests will need to be labeled with the “run-test” label before the quality gate tests will run. This label needs to be set by a RackHD Commit.

The following table show all the Jenkins Instructions and usage:

Instruction Description Detailed Usage
depends on: pr1_url depends on: pr2_url ... Trigger one Jenkins test that using the commits of all interdependent pull requests.

RackHD is a multi repository project, so there are times one new feature needs changes on two or more repositories. In such situation neither Concourse test for single pull request can pass. This command is order to solve this problem.

Recommended usage: for interdependent pull requests, first create pull request one by one, but do not label any PRs with “run-test”. When creating the last pull request include the depend statements in the description:

depends on: pr1_url
depends on: pr2_url

Then set the “run-test” label only on the pull request that includes the depends on instruction.

The interdependent test result will be written back to all interdependent pull requests. The unit test error log will be commented on each related pull request, the functional test error log will only be commented on the main pull request, the one with the “depends on ...” instruction.