This quickstart shows you how to create a small App Engine application that displays a short message.
There are no costs associated with running this guide. Running this sample app alone does not exceed your free quota.
Before you begin
Before running and deploying this quickstart, install the Cloud SDK and then set up a GCP project for App Engine:
Download and install Cloud SDK:
gcloud components update
Create new project:
gcloud projects create [YOUR_PROJECT_NAME] --set-as-default
Verify the project was created:
gcloud projects describe [YOUR_PROJECT_NAME]
You see project details that might look like the following:
createTime: year-month-hour lifecycleState: ACTIVE name: project-name parent: id: '433637338589' type: organization projectId: project-name-id projectNumber: 499227785679
Initialize your App Engine app with your project and choose its region:
gcloud app create --project=[YOUR_PROJECT_NAME]
When prompted, select the region where you want your App Engine application located.
Install the following prerequisites:
Run the following command to install the gcloud component that includes the App Engine extension for Python:
gcloud components install app-engine-python
Prepare your environment for Python development. It is recommended that you
have the latest version of Python,
and other related tools installed on your system. For instructions, refer
to the Python Development Environment Setup Guide.
App Engine locations
App Engine is regional, which means the infrastructure that runs your apps is located in a specific region and is managed by Google to be redundantly available across all the zones within that region.
Meeting your latency, availability, or durability requirements are primary factors for selecting the region where your apps are run. You can generally select the region nearest to your app's users but you should consider the location of the other GCP products and services that are used by your app. Using services across multiple locations can affect your app's latency as well as pricing.
App Engine is available in the following regions:
You cannot change an app's region after you set it.
If you already created an App Engine application, you can view the
region by running the
gcloud app describe command or opening the
App Engine Dashboard in the GCP Console.
The region of your App Engine application is listed under
Download the Hello World app
We've created a simple Hello World app for Python so you can quickly get a feel for deploying an app to Google Cloud Platform. Follow these steps to download Hello World to your local machine.
Clone the Hello World sample app repository to your local machine:
git clone https://github.com/GoogleCloudPlatform/python-docs-samples
Change to the directory that contains the sample code:
Alternatively, you can download the sample as a .zip file and extract it.
Test the application
Test the application using the local development server (
which is included with the SDK.
From within the
hello_worlddirectory where the app's app.yaml configuration file is located, start the local development server with the following command:
The local development server is now running and listening for requests on port 8080. Something go wrong?
- Visit http://localhost:8080/ in your web browser to view the app.
Running the local development server (
To run the local development server, you can either run
specifying the full directory path or you can add
dev_appserver.py to your
PATH environment variable:
If you installed the original App Engine SDK, the tool is located at:
If you installed the Google Cloud SDK, the tool is located at:
Tip: To add the Google Cloud SDK tools to your
PATHenvironment variable and enable command-completion in your shell, you can run:
For more information about running the local development server including how to change the port number, see the Local Development Server reference.
Make a change
You can leave the development server running while you develop your application. The development server watches for changes in your source files and reloads them if necessary.
- Try it now: Leave the development server running, then edit
Hello, World!to something else.
- Reload http://localhost:8080/ to see the results.
Deploy your app
To deploy your app to App Engine, run the following command from within the root
directory of your application where the
app.yaml file is located:
gcloud app deploy
Learn about the optional flags.
gcloud command flags
--versionflag to specify an ID that uniquely identifies that version of your app, otherwise one is generated for you. Example:
--projectflag to specify an alternate GCP project ID to what you initialized as the default in the
gcloud app deploy --version pre-prod-5 --project my-sample-app
View your application
To launch your browser and view the app at
http://[YOUR_PROJECT_ID].appspot.com, run the following command:
gcloud app browse
You have completed this quickstart.
See the following sections for information about cleaning up after this quickstart as well as links to the possible next steps you can take with your deployed applications.
To learn more about this Hello World app, see the Hello World code review section.
Clean upIf you have enabled billing, you can delete your GCP project to avoid incurring charges. This stops billing for all the resources used within that project.
- In the GCP Console, go to the Projects page.
- In the project list, select the project you want to delete and click Delete delete.
- In the dialog, type the project ID, and then click Shut down to delete the project.
Develop a basic Flask app
Learn how to develop and deploy basic Python 2.7 applications that run on the Google App Engine Standard Environment. If you're new to Google App Engine, its related services, and in particular, using App Engine with the Python language, the Flask guide provides deeper explanations for each task than what is found in the Quickstart guide. For more information, see Getting Started with Flask on App Engine Standard Environment.
Use a custom domain
You can serve your App Engine app using your own custom domain instead of
appspot.com. For more information, see Using Custom Domains and
Hello World code review
Hello World is the simplest possible App Engine app: it contains only one service, has only one version, and all of the code is located within the app's root directory. This section describes each of the app files in detail.
This Python script responds to a request with an HTTP header and the message
import webapp2 class MainPage(webapp2.RequestHandler): def get(self): self.response.headers['Content-Type'] = 'text/plain' self.response.write('Hello, World!') app = webapp2.WSGIApplication([ ('/', MainPage), ], debug=True)
app.yaml configuration file defines several options for the app, and
describes which handler scripts should be used for which URLs.
runtime: python27 api_version: 1 threadsafe: true handlers: - url: /.* script: main.app
From top to bottom, this configuration file says the following about this application:
- This code runs in the
python27runtime environment, API version
- This application is
threadsafeso the same instance can handle several simultaneous requests. Threadsafe is an advanced feature and can result in erratic behavior if your application is not specifically designed to be threadsafe.
- Every request to a URL whose path matches the regular expression
/.*(all URLs) should be handled by the
appobject in the
Learn the whole platform
Now that you know what it's like to develop and deploy App Engine apps, you can stretch out and see the rest of Google Cloud Platform. For a guided walkthrough that teaches you how to create an application that uses the entire platform, not just App Engine, check out our Creating a Guestbook quickstart in which you expand this simple application to become a fully-fledged Guestbook application that lets authenticated Google accounts post messages to a public page.
Learn more about App Engine standard environment
Here are some topics to help you to continue learning about App Engine.