Using the Python platform - AWS App Runner
Python runtime configurationPython runtime examples

Using the Python platform

The AWS App Runner Python platform provides managed runtimes. Each runtime makes it easy to build and run containers with web applications based on a Python version. When you use a Python runtime, App Runner starts with a managed Python runtime image. This image is based on the Amazon Linux Docker image and contains the runtime package for a version of Python and some tools and popular dependency packages. App Runner uses this managed runtime image as a base image, and adds your application code to build a Docker image. It then deploys this image to run your web service in a container.

You specify a runtime for your App Runner service when you create a service using the App Runner console or the CreateService API operation. You can also specify a runtime as part of your source code. Use the runtime keyword in a App Runner configuration file that you include in your code repository. The naming convention of a managed runtime is <language-name><major-version>.

For valid Python runtime names and versions, see Python runtime release information.

App Runner updates the runtime for your service to the latest version on every deployment or service update. If your application requires a specific version of a managed runtime, you can specify it using the runtime-version keyword in the App Runner configuration file. You can lock to any level of version, including a major or minor version. App Runner only makes lower-level updates to the runtime of your service.

Version syntax for Python runtimes: major[.minor[.patch]]

For example: 3.8.5

The following examples demonstrate version locking:

  • 3.8 – Lock the major and minor versions. App Runner updates only patch versions.

  • 3.8.5 – Lock to a specific patch version. App Runner doesn't update your runtime version.

Topics

Python runtime configuration

When you choose a managed runtime, you must also configure, as a minimum, build and run commands. You configure them while creating or updating your App Runner service. You can do this using one of the following methods:

  • Using the App Runner console – Specify the commands in the Configure build section of the creation process or configuration tab.

  • Using the App Runner API – Call the CreateService or UpdateService API operation. Specify the commands using the BuildCommand and StartCommand members of the CodeConfigurationValues data type.

  • Using a configuration file – Specify one or more build commands in up to three build phases, and a single run command that serves to start your application. There are additional optional configuration settings.

Providing a configuration file is optional. When you create an App Runner service using the console or the API, you specify if App Runner gets your configuration settings directly when it's created or from a configuration file.

Python runtime examples

The following examples show App Runner configuration files for building and running a Python service. The last example is the source code for a complete Python application that you can deploy to a Python runtime service.

Note

The runtime version that's used in these examples is 3.7.7. You can replace it with a version you want to use. For latest supported Python runtime version, see Python runtime release information.

This example shows a minimal configuration file that you can use with a Python managed runtime. For the assumptions that App Runner makes with a minimal configuration file, see Configuration file examples.

Example apprunner.yaml
version: 1.0
runtime: python3 
build:
  commands:
    build:
      - pip install pipenv
      - pipenv install 
run: 
  command: python app.py

This example shows the use of all configuration keys with a Python managed runtime.

Note

The runtime version that's used in these examples is 3.7.7. You can replace it with a version you want to use. For latest supported Python runtime version, see Python runtime release information.

Example apprunner.yaml
version: 1.0
runtime: python3 
build:
  commands:
    pre-build:
      - wget -c https://s3.amazonaws.com/DOC-EXAMPLE-BUCKET/test-lib.tar.gz -O - | tar -xz
    build:        
      - pip install pipenv
      - pipenv install
    post-build:
      - python manage.py test
  env:
    - name: DJANGO_SETTINGS_MODULE
      value: "django_apprunner.settings"
    - name: MY_VAR_EXAMPLE
      value: "example"
run:
  runtime-version: 3.7.7
  command: pipenv run gunicorn django_apprunner.wsgi --log-file -
  network: 
    port: 8000
    env: MY_APP_PORT  
  env:
    - name: MY_VAR_EXAMPLE
      value: "example"
  secrets:
    - name: my-secret
      value-from: "arn:aws:secretsmanager:us-east-1:123456789012:secret:testingstackAppRunnerConstr-kJFXde2ULKbT-S7t8xR:username::"
    - name: my-parameter
      value-from: "arn:aws:ssm:us-east-1:123456789012:parameter/parameter-name"
    - name: my-parameter-only-name
      value-from: "parameter-name"

This example shows the source code for a complete Python application that you can deploy to a Python runtime service.

Example requirements.txt
pyramid==2.0
Example server.py
from wsgiref.simple_server import make_server
from pyramid.config import Configurator
from pyramid.response import Response
import os

def hello_world(request):
    name = os.environ.get('NAME')
    if name == None or len(name) == 0:
        name = "world"
    message = "Hello, " + name + "!\n"
    return Response(message)

if __name__ == '__main__':
    port = int(os.environ.get("PORT"))
    with Configurator() as config:
        config.add_route('hello', '/')
        config.add_view(hello_world, route_name='hello')
        app = config.make_wsgi_app()
    server = make_server('0.0.0.0', port, app)
    server.serve_forever()
Example apprunner.yaml
version: 1.0
runtime: python3
build:
  commands:
    build:
      - pip install -r requirements.txt
run:
  command: python server.py