Parallelizing Builds In Travis CI

Badgeyay project is now divided into two parts i.e front-end of emberJS and back-end with REST-API programmed in Python. Now, one of the challenging job is that, it should support the uncoupled architecture. It should therefore run tests for the front-end and backend i.e, of two different languages on isolated instances by making use of the isolated parallel builds.

In this blog, I’ll be discussing how I have configured Travis CI to run the tests parallely in isolated parallel builds in Badgeyay in my Pull Request.

First let’s understand what is Parallel Travis CI build and why we need it. Then we will move onto configuring the travis.yml file to run tests parallely. Let’s get started and understand it step by step.

Why Parallel Travis CI Build?

The integration test suites tend to test more complex situations through the whole stack which incorporates front-end and back-end, they likewise have a tendency to be the slowest part, requiring various minutes to run, here and there even up to 30 minutes. To accelerate a test suite like that, we can split it up into a few sections utilizing Travis build matrix feature. Travis will decide the build matrix based on environment variables and schedule two builds to run.

Now our objective is clear that we have to configure travis.yml to build parallel-y. Our project requires two buildpacks, Python and node_js, running the build jobs for both them would speed up things by a considerable amount.It seems be possible now to run several languages in one .travis.yml file using the matrix:include feature.

Below is the code snippet of the travis.yml file  for the Badgeyay project in order to run build jobs in a parallel fashion.

sudo: required
dist: trusty

# check different combinations of build flags which is able to divide builds into “jobs”.

# Helps to run different languages in one .travis.yml file

# First Job in Python.
- language: python3

- python-dev

- 3.5
- $HOME/backend/.pip-cache/

- sudo apt-get -qq update
- sudo apt-get -y install python3-pip
- sudo apt-get install python-virtualenv

- virtualenv  -p python3 ../flask_env
- source ../flask_env/bin/activate
- pip3 install -r backend/requirements/test.txt --cache-dir

- export DISPLAY=:99.0
- sh -e /etc/init.d/xvfb start
- sleep 3

- python backend/app/ >> log.txt 2>&1  &
- python backend/app/ > /dev/null &
- py.test --cov ../  ./backend/app/tests/

- bash <(curl -s

# Second Job in node js.
- language: node_js
- "6"

chrome: stable

- $HOME/frontend/.npm

# See for details.
- JOBS=1

- cd frontend
- npm install
- npm install -g ember-cli
- npm i [email protected] --save-dev
- npm config set spin false

- npm run lint:js
- npm test


Now, as we have added travis.yml and pushed it to the project repo. Here is the screenshot of passing Travis CI after parallel build jobs.

The related PR of this work is

Resources :

Travis CI documentation – Link