Configuring your app with app.yaml

An App Engine app is configured using an app.yaml file, that contains CPU, memory, network and disk resources, scaling, and other general settings including environment variables.

About app.yaml files

You can specify the runtime configuration for your Node.js app, including versions and URLs, in the app.yaml file. This file acts as a deployment descriptor of a specific service version.

You must first create the app.yaml file for the default service of your app before you can create and deploy app.yaml files for additional services.

The following app.yaml demonstrates how to configure your app for Node.js 16 and earlier, and 18 and later. Note that you must update your app.yaml file to use the new version. See Node.js runtime for more information about using the new versions.

v18 and later 

runtime: nodejs
env: flex
runtime_config:
  operating_system: ubuntu22
# This sample incurs costs to run on the App Engine flexible environment.
# The settings below are to reduce costs during testing and are not appropriate
# for production use. For more information, see:
# https://cloud.google.com/appengine/docs/flexible/nodejs/configuring-your-app-with-app-yaml
manual_scaling:
  instances: 1
resources:
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10

v16 and earlier 

runtime: nodejs
env: flex

# This sample incurs costs to run on the App Engine flexible environment.
# The settings below are to reduce costs during testing and are not appropriate
# for production use. For more information, see:
# https://cloud.google.com/appengine/docs/flexible/nodejs/configuring-your-app-with-app-yaml
manual_scaling:
  instances: 1
resources:
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10

Depending on the complexity of your app's service, you might only need to define a few elements in the corresponding app.yaml file. The following example demonstrates what a simple Node.js app might require in the flexible environment:

You can specify a unique name for your app.yaml files, but then you must specify the file name with the deployment command as well. For example, if you name your app.yaml file service-name-app.yaml or app.flexible.yaml, then you must deploy your app using either:

gcloud app deploy service-name-app.yaml
gcloud app deploy app.flexible.yaml
To learn more about structuring multiple services and app.yaml files in your app, see Structuring web services.

All configuration elements

For a complete list of all the supported elements in this configuration file, see the app.yaml reference.