very easy way to deploy nodejs app on google engine.
create your index.js file
create your app.yaml file
app.yaml should contains only one line , in my easy test.
runtime: nodejs10
on the same folder i run the next command
gcloud init
gcloud projects create yaniv2cappengine
gcloud app create --project=yaniv2cappengine
gcloud config set project yaniv2cappengine
gcloud app deploy
that all - enjoy
Yaniv Tzanany