REGION_ID is an abbreviated code that Google assigns
based on the region you select when you create your app. The code does not
correspond to a country or province, even though some region IDs may appear
similar to commonly used country and province codes. Including
REGION_ID.r in App Engine URLs is optional for
existing apps and will soon be required for all new apps.
To ensure a smooth transition, we are slowly updating App Engine to use region IDs. If we haven't updated your Google Cloud project yet, you won't see a region ID for your app. Since the ID is optional for existing apps, you don't need to update URLs or make other changes once the region ID is available for your existing apps.
Learn more about region IDs.
Learn how to run your application locally, deploy it, and test on App Engine.
To test your application's functionality before deploying, run your application
in your local environment with the development tools that you usually use. For
Before deploying your application
Before you can deploy your application:
- The Owner of the Cloud project must enable App Engine.
- You must ensure that your user account includes the required privileges.
Deploying your applicationDeploy your application to App Engine using the
gcloud app deploycommand.
To programmatically deploy your apps, use the Admin API.
Deploying a service
You deploy your application to App Engine by deploying versions of your application's services and each of their configuration files.
To deploy a version of your application's service, run the following command
from the directory where the
app.yaml file of your service is located:
gcloud app deploy
Specifying no files with the command deploys only the
app.yaml file in your
current directory. By default, the
deploy command generates a unique ID for
the version that you deploy, deploys the version to the
Google Cloud project you configured the
gcloud tool to use, and
routes all traffic to the new version.
You can change the default behavior of the command by targeting specific files or including additional parameters:
- To deploy the other configuration files of your service, you must target and
deploy each file separately. For example:
gcloud app deploy cron.yaml gcloud app deploy dispatch.yaml gcloud app deploy index.yaml
- To specify a custom version ID, use the
- To prevent traffic from being automatically routed to the new version, use
- To deploy to a specific Google Cloud project, use the
For example, to deploy the service defined by the
app.yaml file to a specific
Google Cloud project, assign it a custom version ID, and prevent traffic
from being routed to the new version:
gcloud app deploy --project PROJECT_ID --version VERSION_ID --no-promote
For more information about this command, see the
gcloud app deploy
Deploying multiple services
You use the same deployment command for deploying or updating the multiple services that make up your application.
To deploy multiple services, separately deploy each service's
file. You can specify multiple files with a single
gcloud app deploy command:
gcloud app deploy service1/app.yaml service2/app.yaml
Requirements for deploying multiple services
- You must initially deploy a version of your application to the
defaultservice before you can create and deploy subsequent services.
- The ID of each of your services must be specified in their corresponding
app.yamlconfiguration files. To specify the service ID, include the
serviceelement definition in each configuration file. By default, excluding this element definition from your configuration file deploys the version to the
You can use a
.gcloudignore file to specify files and directories that will
not be uploaded to App Engine when you deploy your services. This is
useful for ignoring build artifacts and other files that do not need to be
uploaded with your deployment.
Managing build images
Each time you deploy a new version, a container image is created using the Cloud Build service. That container image then runs in the App Engine standard environment.
Built container images are stored in the
in Container Registry. You can
download these images to keep or run elsewhere. Once deployment is complete,
App Engine no longer needs the
container images. Note that they are not automatically deleted, so to avoid
reaching your storage quota, you can safely delete any images you don't need.
For more information about managing images in Container Registry, see the
Container Registry documentation.
Viewing your application
After you deploy your application to App Engine, you can run the
following command to launch your browser and view it at
gcloud app browse
Testing on App Engine before shifting traffic
Before configuring a new version to receive traffic, you can test it on
App Engine. For example, to test a new version of your
Deploy your new version, but prevent traffic from being automatically routed to the new version:
gcloud app deploy --no-promote
Access your new version by navigating to the following URL:
Now you can test your new version in the App Engine runtime environment. You can debug your application by viewing its logs. For more information, see Writing Application Logs.
Requests sent to
https://PROJECT_ID.REGION_ID.r.appspot.comare be routed to the version previously configured to receive traffic.
When you want to send traffic to the new version, use the Cloud Console to migrate traffic:
Select the version you just deployed and click Migrate traffic.
You can use the same process to test new versions of other services by replacing
default in the URL with your service's name:
For more information about targeting specific services and versions, see How Requests are Routed.