502 Bad Gateway with nginx | Google App Engine | Node JS

Question

I am hosting the web app on Google Cloud Platform with App Engine and I am using ExpressJS and MongoDB, which is hosted on mLab.

Everything worked well until 1/1/201

Answer 1

app should always listen to port 8080, google forwards all request from 80 to 8080 https://cloud.google.com/appengine/docs/flexible/custom-runtimes/build#listen_to_port_8080