Setting up your Python development environment for Elastic Beanstalk

This topic provides instructions to set up a Python development environment to test your application locally prior to deploying it to AWS Elastic Beanstalk. It also references websites that provide installation instructions for useful tools.

For common setup steps and tools that apply to all languages, see Configuring your development machine for use with Elastic Beanstalk.

To follow the procedures in this guide, you will need a command line terminal or shell to run commands. Commands are shown in listings preceded by a prompt symbol ($) and the name of the current directory, when appropriate.

~/eb-project$ this is a command
this is output

On Linux and macOS, you can use your preferred shell and package manager. On Windows you can install the Windows Subsystem for Linux to get a Windows-integrated version of Ubuntu and Bash.

For common setup steps and tools that apply to all languages, see Configuring your development machine for use with Elastic Beanstalk.

Prerequisites

The following list provides the common prerequisites for working with Elastic Beanstalk and your Python applications:

• Python language – Install the version of the Python language that's included on your chosen Elastic Beanstalk Python platform version. For a list of our supported Python language versions, see Supported Python platforms in the AWS Elastic Beanstalk Platforms guide. If you don't already have Python set up on your development machine, see the Python downloads page on the Python website.

• pip utility – The pip utility is Python's package installer. It installs and lists dependencies for your project, so that Elastic Beanstalk knows how to set up your application's environment. For more information about pip, see the pip page on the pip.pypa.io website.

• (Optional) The Elastic Beanstalk Command Line Interface (EB CLI) – The EB CLI can package your application with the necessary deployment files. It can also create an Elastic Beanstalk environment and deploy your application to it. You can also make deployments via the Elastic Beanstalk console, so the EB CLI is not strictly necessary.

• A working SSH installation – You can connect to your running instances with the SSH protocol to examine or debug a deployment.

• virtualenv package – This virtualenv tool creates a development and test environment for your application. Elastic Beanstalk can replicate this environment without installing extra packages that aren't required by your application. For more information, see the virtualenv website. After installing Python, you can install virtualenv package with the following command:

  $ pip install virtualenv

Using a virtual environment

Once you have the prerequisites installed, set up a virtual environment with virtualenv to install your application's dependencies. By using a virtual environment, you can discern exactly which packages are needed by your application so that the required packages are installed on the EC2 instances that are running your application.

To set up a virtual environment

1. Open a command-line window and type:

   $ virtualenv /tmp/eb_python_app

   Replace eb_python_app with a name that makes sense for your application (using your application's name is a good idea). The virtualenv command creates a virtual environment for you in the specified directory and prints the results of its actions:

   Running virtualenv with interpreter /usr/bin/python
   New python executable in /tmp/eb_python_app/bin/python3.7
   Also creating executable in /tmp/eb_python_app/bin/python
   Installing setuptools, pip...done.

2. Once your virtual environment is ready, start it by running the activate script located in the environment's bin directory. For example, to start the eb_python_app environment created in the previous step, you would type:

   $ source /tmp/eb_python_app/bin/activate

   The virtual environment prints its name (for example: (eb_python_app)) at the beginning of each command prompt, reminding you that you're in a virtual Python environment.

3. To stop using your virtual environment and go back to the system’s default Python interpreter with all its installed libraries, run the deactivate command.

   (eb_python_app) $ deactivate

Note

Once created, you can restart the virtual environment at any time by running its activate script again.

Configuring a Python project for Elastic Beanstalk

You can use the Elastic Beanstalk CLI to prepare your Python applications for deployment with Elastic Beanstalk.

To configure a Python application for deployment with Elastic Beanstalk

1. From within your virtual environment, return to the top of your project's directory tree (python_eb_app), and type:

   pip freeze >requirements.txt

   This command copies the names and versions of the packages that are installed in your virtual environment to requirements.txt, For example, if the PyYAML package, version 3.11 is installed in your virtual environment, the file will contain the line:

   PyYAML==3.11

   This allows Elastic Beanstalk to replicate your application's Python environment using the same packages and same versions that you used to develop and test your application.

2. Configure the EB CLI repository with the eb init command. Follow the prompts to choose a region, platform and other options. For detailed instructions, see Managing Elastic Beanstalk environments with the EB CLI.

By default, Elastic Beanstalk looks for a file called application.py to start your application. If this doesn't exist in the Python project that you've created, some adjustment of your application's environment is necessary. You will also need to set environment variables so that your application's modules can be loaded. See Using the Elastic Beanstalk Python platform for more information.