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 example, you can usually run a Flask application with Flask's development server using:
Django applications can be started using:
python manage.py runserver
To simulate a production App Engine environment, you can run the full Web Server
Gateway Interface (WSGI) server locally. To do this, use the same command
entrypoint in your
app.yaml, for example:
gunicorn -b :$PORT main:app
Deploying your application
Deploy your app to App Engine using the
gcloud app deploy
command. This command
automatically builds a container image by using the
Container Builder service and then deploys
that image to the App Engine flexible environment. The container
will include any local modifications that you've made to the runtime image.
To programmatically deploy your apps, use the Admin API.
Before you begin
Before you can deploy your app:
Ensure that your user account includes the required privileges.
Ensuring successful deployment
If you enable updated health checks, deployments are rolled back if your application does not reach healthy status.
When you deploy your first application to the flexible environment, there might be a delay as your virtual machine (VM) and other infrastructure are set up. After the initial setup, health checks begin to confirm that your instance is healthy and ready to receive traffic. If your application does not reach ready status in a specified amount of time, then your deployment fails and is rolled back.
Your application might need more time to become ready. For example, you might
initialize your application by downloading large files or preloading caches. If
you are using
updated health checks, then you can increase the amount of time by modifying the
app_start_timeout configuration setting
Deploying a service
You deploy your app to App Engine by deploying versions of your app's services and each of their configuration files.
To deploy a version of your app'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 of a given
service. By default, the command automatically generates a unique ID for
the version that you deploy, deploys your version to the GCP project
which was used to initialize the
gcloud tool, and also routes all traffic to
You can change the default behavior of the command by targeting specific files or including additional command parameters:
To deploy the other configuration files of your service, you must target and deploy each file separately. Examples:
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 the
To deploy your app to a specific GCP project, use the
For example, to deploy the service defined by
app.yaml to a specific
GCP 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 reference.
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, you must separately deploy each service's
app.yaml file. For example:
gcloud app deploy service1/app.yaml gcloud app deploy service2/app.yaml
You can specify multiple files with a single deploy command:
gcloud app deploy service1/app.yaml service2/app.yaml
Requirements for deploying multiple services
You must initially deploy a version of your app 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, you include the
serviceelement definition in each configuration file. By default, excluding this element definition from your configuration file deploys the version to the
Manually building a container for deployment
To build your container images outside of Google Cloud Platform, you must
first upload your images to a container image repository before you can deploy
your images to App Engine with the
gcloud app deploy command.
For example, if you build your container images locally with Docker, you can
push those images to Google Container
Registry and then
specify the URL of your image in the
--image-url flag of the command:
gcloud app deploy --image-url gcr.io/YOUR_PROJECT_ID/YOUR_CONTAINER_IMAGE
Using automated continuous deployment pipelines
You can use Container Builder to automate deployments in continuous deployment pipelines. For more information, see Deploying artifacts, and Automating Builds using Build Triggers in the Container Builder documentation.
Docker base images for Python
If you'd like to build a Python custom runtime application from scratch, use a provided base image in your Dockerfile:
|Runtime||Docker command||Equivalent Google
|Python (2.7, 3.6 can be specified in the Dockerfile)||
Viewing your application
After you deploy your app to App Engine, you can run the following
command to launch your browser and view the app at
gcloud app browse
Testing on App Engine
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 and include the
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 app by viewing its logs. For more information, see Writing Application Logs.
Requests sent to
http://YOUR_PROJECT_ID.appspot.comwill still be routed to the version previously configured to receive traffic.
When you want to send traffic to the new version, use the GCP 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
default in the URL with your service's name:
For more information about targeting specific services and versions, see How Requests are Routed.
The following is a common error message that you might encounter when deploying apps:
PERMISSION_DENIED: Operation not allowed
The "appengine.applications.create" permission is required.
- If the GCP project does not include the required
gcloud app deploycommand can fail when it tries to run the
gcloud app createcommand. Only accounts with Owner role have the necessary permissions to create App Engine applications.