An App Engine app is configured using an
file, that contains the runtime, handlers, scaling, and other general settings
including environment variables.
You can specify the runtime configuration for your Ruby app,
including versions and URLs, in the
app.yamlfile. 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.
app.yaml file requires only the
runtime element for a simple
Ruby app in the standard environment, for
runtime: ruby25 # or ruby26 or ruby27 for Ruby 2.6 (beta) or Ruby 2.7 (beta)
App Engine provides default values for all other settings, including the F1 instance class, which determines the memory and CPU resources that are available to your app, and automatic scaling, which controls how and when new instances of your app are created.
If you need to override the default settings, create an
app.yaml file and
specify the settings you need. For more information, see
app.yaml file reference.
You can specify a unique name for your
app.yaml files, but then you must
specify the file name with the deployment
as well. For example, if you name your
app.standard.yaml, then you must deploy your app using either:
To learn more about structuring multiple services and
gcloud app deploy service-name-app.yaml gcloud app deploy app.standard.yaml
app.yamlfiles in your app, see Structuring web services.
All configuration elements
For a complete list of all the supported elements in this configuration file,