# install travis ruby command line utility
> sudo gem install travis
> travis --version
# encrypt DOCKER_EMAIL, DOCKER_USER & DOCKER_PASSWORD
> travis encrypt DOCKER_EMAIL=your-docker-hub-email@gmail.com --add env.global.DOCKER_EMAIL
> travis encrypt DOCKER_USER=your-docker-hub-username --add env.global.DOCKER_USER
> travis encrypt DOCKER_PASS=your-docker-hub-password --add env.global.DOCKER_PASS
References: