travis-dependent-builds

Try to trigger downstream Travis projects from upstream Travis projects hosted on Github (See the prerequisites below please).

Note: If you need to trigger dependent builds with Appveyor, look at my gist here: Trigger Appveyor dependent build

This will also work if your upstream project belongs to a different organization or user (inter-project/inter-organization build dependencies). One needs to generate a Travis access token to use the Travis API, adding the token to the upstream project, will enable to trigger downstream projects which are owned by the user of the Travis access token.

Consider the following scenario (cf. figure below), i.e. the DOWNSTREAM projects depend on the UPSTREAM project and need to be build if the UPSTREAM project was triggered by a new commit. Therefore we can ensure, if the UPSTREAM project has changed and was tested with success, that the dependent DOWNSTREAM projects are also tested against the changes in the upstream project. This is to make sure that the changes in the UPSTREAM project did really not harm the DOWNSTREAM projects by this given commit.

Please note, if a dependent project has been triggered by our scripts, we log a message in the dependent Travis project (i. e. triggered by upstream project with commit id 1c1234), to make it easy to find the commit of the UPSTREAM project which triggered the current dependent project build and eventually made the DOWNSTREAM project fail.

Usage

Consider you have an empty Python upstream project for now, e. g.:

language: 
   - python

python:
   - "2.6"

script:
   -

To trigger a downstream project (either your own or from a different user), e. g. after success of testing, or in general after all your tests have been run, insert this snippet (note you can exchange after_script with for instance after_success, or anything you think should be appropriate for your usecase) into your travis.yml:

before_script:
   - gem install travis

after_script:
   - curl -LO https://raw.github.com/stephanmg/travis-dependent-builds/master/trigger.sh
   - chmod +x trigger.sh
   - ./trigger.sh stephanmg downstream master $TRAVIS_ACCESS_TOKEN 

This results in the following travis yml file:

language: 
   - python

python:
   - "2.6"

before_script:
   - gem install travis

script:
   -

after_script:
   - curl -LO https://raw.github.com/stephanmg/travis-dependent-builds/master/trigger.sh
   - chmod +x trigger.sh
   - ./trigger.sh stephanmg downstream master $TRAVIS_ACCESS_TOKEN 

Explanation

The first curl statement, fetch the most recent version of the helper scripts trigger.sh from the repository you are currently reading this README. The chmod makes the trigger.sh script executable. The next line actually triggers a downstream project, termed downstream, of the github/travis user stephanmg, if the upstream project uses the master branch then a new build of the corresponding master branch of the downstream project will be scheduled. The TRAVIS_ACCESS_TOKEN is the environement variable actually is your github token which you are supposed to provide in the corresponding downstream travis project you want to trigger (cf. prerequisites below).

Prerequisites

1. Github Token: As a prerequisit you need to generate a user access token from Github's website, e. g. go to your user profile, navigate to settings, generate an as restrictive as possible Github token, and assign it a name, e. g. Travis.
2. Set the value of TRAVIS_ACCESS_TOKEN in the settings section of the corresponding upstream Travis project. Assign an environment variable for the TRAVIS_ACCESS_TOKEN which is your Github user access token (Travis). Make sure you do not enable (Include value in build log for security reasons!)
3. Trigger downstream project from upstream project with trigger.sh.

Example: Navigate to your Travis projects, for instance if your user is stephanmg (github/travis) and your project downstream and upstream then go to: https://travis-ci.org/stephanmg/upstream/settings There you need to define a variable, termed e. g. TRAVIS_ACCESS_TOKEN and assign the value of the token you generated previously in Github (user access token: Travis). This variable will be available in our travis.yml file by $TRAVIS_ACCESS_TOKEN. This allows you to login with your user passwordless in a e. g. shell script on the travis build environment and use the Travsi API in your given upstream travis project upstream to trigger a downstream project. Once logged in, use the trigger.sh script to trigger a new build with some options (See below). Note that this could also be a downstream project of a different user or organization you have access to!

• Optionally specify a branch to use
• Optionally multiple trigger statements

In the after_script section you could then have a various of trigger statements, e. g.:

after_script:
   - ./trigger.sh stephanmg downstream master $TRAVIS_ACCESS_TOKEN 
   - ./trigger.sh othergithubuser downstreamProject2 devel $OUR_AGREED_ACCESS_TOKEN_VAR
   - ./trigger ...

Possible future features

• upstream and downstream project branch are assumed to be the same, this could be more flexible, i. e. allow for different branches
• provide a configuration file for the trigger.sh script, i. e. reduce call in your travis.yml file to ./trigger.sh --conf dependent-builds.yml, i. e. storing all relevant information in dependent-builds.yml file.

Caveats

If you're using a build matrix for your UPSTREAM project, then for each entry you end up with a triggered DOWNSTREAM project. There might be a workaround for this in the future - or if included in the Travis API soon hopefully.

Questions

Feel free to message me - see my profile

See

Travis API documentation