This quickstart shows you how to create a small App Engine application that displays a short message.
Before you begin
Before running and deploying this quickstart, you must install the Cloud SDK and create or use an existing Cloud Platform Console project:
Create a new Cloud Platform Console project or retrieve the project ID of an existing project from the Google Cloud Platform Console:
Tip: Retrieve a list of your existing project IDs with gcloud.
To install the
gcloudtool, you install and then initialize the Google Cloud SDK:
Listing your Cloud Platform Console project IDs with
From the command line, run:
gcloud projects list
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
Then go 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, start the local development server with the following command:
The local development server is now running and listening for requests on port 8080.
Visit http://localhost:8080/ in your web browser to view the app.
For more information about running the local development server, see the Python Development Server reference.
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 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:
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
--projectflag to specify an alternate Cloud Platform Console project ID to what you initialized as the default in the
-vflag to specify a version ID, otherwise one is generated for you. Example:
To learn more about deploying your app from the command line, see Deploying a Python 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.
To avoid incurring charges to your Google Cloud Platform account for the resources used in this quickstart:
- Go to the Cloud Platform Console.
- In the list of projects, select the project that you want to shut down.
- In the prompt, type your project ID to confirm the deletion.
- Click Shut down to schedule your project for deletion.
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.