title: cloudbuild.yaml build pipeline for python flask app on gcloud compute engine
body: <p>I have a Python Flask app which needs a library which is not preinstalled on Gcloud compute instances <code>libsndfile1</code> — also why I can't run this through app engine. I have set up a cloud build pipeline so my <code>cloudbuild.yaml</code> triggers every time I push to master on my repository.</p>
  <p>Here are my 2 questions:</p>
  <ol>
  <li>Where does the cloudbuild.yaml execute it's instructions?</li>
  <li>How do I make the cloudbuild.yaml execute <code>apt-get install libsndfile1 python3 python3-pip</code> and then also execute <code>pip3 install requirements.txt</code> where <code>requirements.txt</code> is a file in the repository that triggers the cloud build?</li>
  </ol>
  <p>Disclaimer: I am an ultra-beginner with docker but if you think that docker is the only way to do it then please explain how something like this can be done.</p>