run-travis-on-docker.md

@see https://medium.com/google-developers/how-to-run-travisci-locally-on-docker-822fc6b2db2e

1. Install Docker
2. Install Travis on Docker

# choose the image according to the language chosen in .travis.yml
$ docker run -it -u travis quay.io/travisci/travis-jvm /bin/bash
# now that you are in the docker image, switch to the travis user
sudo — travis
# Install a recent ruby (default is 1.9.3)
rvm install 2.3.0
rvm use 2.3.0
# Install travis-build to generate a .sh out of .travis.yml
cd builds \
git clone https://github.com/travis-ci/travis-build.git \
cd travis-build \
gem install travis \
travis # to create ~/.travis \
ln -s `pwd` ~/.travis/travis-build \
bundle install
# Create ssh key for Github
ssh-keygen -t rsa -b 4096 -C “YOUR EMAIL REGISTERED IN GITHUB”
# Click enter to use default location for key
# You can choose empty passphrase by clicking enter twice
# Now that we have the key, let’s share with Github
less ~/.ssh/id_rsa.pub
# Copy the contents of the id_rsa.pub

3. Go to your Github SSH key settings
4. Create a new ssh key with title: “docker key”: “PASTE THE KEY CONTENTS HERE”
5. Go back to docker terminal

# Create project dir, assuming your project is `AUTHOR/PROJECT` on GitHub
cd ~/builds \
mkdir AUTHOR \
cd AUTHOR \
git clone git@github.com:AUTHOR/PROJECT.git \
cd PROJECT
# change to the branch or commit you want to investigate
# compile travis script into bash script
travis compile > ci.sh
# Go to bash script and fix the branch name
vi ci.sh
# in Vi type “/branch” to search and add the right branch name
# — branch\=\’\NEW_BRANCH’\
# You most likely will need to edit ci.sh as it ignores ‘matrix’ and ‘env’ keywords
bash ci.sh