git clone git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git
cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream
Unfortunately as of writing this (Oct 18, 2017) there is no built in integration for multiple target groups per AWS ECS service. Here are a few things you can try: