An App Engine app is configured using an app.yaml
file, that contains the runtime, handlers, scaling, and other general settings
including environment variables.
About app.yaml files
You can specify the runtime configuration for your Ruby 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.
Generally, your app.yaml file requires only the runtime element for a simple
Ruby app in the standard environment, for
example:
runtime: ruby33
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
command
as well. For example, if you name your app.yaml file service-name-app.yaml
or app.standard.yaml, then you must deploy your app using either:
gcloud app deploy service-name-app.yaml
gcloud app deploy app.standard.yaml
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.