Using the Python platform - AWS App Runner

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.

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.

Callouts for specific runtime versions

Note

App Runner now runs an updated build process for applications based on the following runtime versions: Python 3.11 and Node.js 18. If your application runs on either one of these runtime versions, see Managed runtime versions and the App Runner build for more information about the revised build process. Applications that use all other runtime versions are not affected, and they continue to use the original build process.

Python 3.11 (revised App Runner build)

Use the following settings in the apprunner.yaml for the managed Python 3.11 runtime.

  • Set the runtime key in the Top section to python311

    Example
    runtime: python311
  • Use the pip3 instead of pip to install dependencies.

  • Use the python3 interpreter instead of python.

  • Run the pip3 installer as a pre-runcommand. Python installs dependencies outside of the /app directory. Since App Runner runs the revised App Runner build for Python 3.11, anything installed outside of the /app directory through commands in the Build section of the apprunner.yaml file will be lost. For more information, see The revised App Runner build.

    Example
    run: runtime-version: 3.11 pre-run: - pip3 install pipenv - pipenv install - python3 copy-global-files.py command: pipenv run gunicorn django_apprunner.wsgi --log-file -

For more information, also see the example of an extended configuration file for Python 3.11 later in this topic.

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 and 3.11. 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.

Python 3.11 uses the pip3 and python3 commands. For more information, see the example of an extended configuration file for Python 3.11 later in this topic.

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.

Python 3.11 uses the pip3 and python3 commands. For more information, see the example of an extended configuration file for Python 3.11 later in this topic.

Example apprunner.yaml
version: 1.0 runtime: python3 build: commands: pre-build: - wget -c https://s3.amazonaws.com/amzn-s3-demo-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 use of all configuration keys with a Python 3.11 managed runtime in the apprunner.yaml. This example include a pre-run section, since this version of Python uses the revised App Runner build.

The pre-run parameter is only supported by the revised App Runner build. Do not insert this parameter in your configuration file if your application uses runtime versions that are supported by the original App Runner build. For more information, see Managed runtime versions and the App Runner build.

Note

The runtime version that's used in these examples is 3.11. 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: python311 build: commands: pre-build: - wget -c https://s3.amazonaws.com/amzn-s3-demo-bucket/test-lib.tar.gz -O - | tar -xz build: - pip3 install pipenv - pipenv install post-build: - python3 manage.py test env: - name: DJANGO_SETTINGS_MODULE value: "django_apprunner.settings" - name: MY_VAR_EXAMPLE value: "example" run: runtime-version: 3.11 pre-run: - pip3 install pipenv - pipenv install - python3 copy-global-files.py 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