This sample code helps get you started with a simple Flask web service deployed by AWS Elastic Beanstalk and AWS CloudFormation.
This sample includes:
- README.md - this file
- buildspec.yml - this file is used by AWS CodeBuild to package your application for deployment to AWS Lambda
- requirements.txt - this file is used install Python dependencies needed by the Flask application
- setup.py - this file is used by Python's setuptools library to describe how your application will be packaged and installed
- helloworld/ - this directory contains the Python source code for your Flask application
- tests/ - this directory contains unit tests for your application
- .ebextensions/ - this directory contains the configuration files that allow AWS Elastic Beanstalk to deploy your application
- template.yml - this file contains the description of AWS resources used by AWS CloudFormation to deploy your infrastructure
- template-configuration.json - this file contains the project ARN with placeholders used for tagging resources with the project ID
These directions assume you want to develop on your development environment or a Cloud9 environment, and not from the Amazon EC2 instance itself. If you're on the Amazon EC2 instance, the virtual environment is already set up for you, and you can start working on the code.
To work on the sample code, you'll need to clone your project's repository to your local computer. You can find instructions in the AWS CodeStar user guide at https://docs.aws.amazon.com/codestar/latest/userguide/getting-started.html#clone-repo.
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Create a Python virtual environment for your Flask project. This virtual environment allows you to isolate this project and install any packages you need without affecting the system Python installation. At the terminal, type the following command:
$ python3 -m venv ./venv -
Activate the virtual environment:
$ source ./venv/bin/activate -
Install Python dependencies for this project:
$ pip install -r requirements.txt -
Install the sample application code into your virtual environment:
$ python setup.py install -
Start the Flask development server:
$ python helloworld/application.py --port 8000 -
Open http://127.0.0.1:8000/ in a web browser to view the output of your service.
Once you have a virtual environment running, you can start making changes to the sample Flask web service. We suggest making a small change to application.py first, so you can see how changes pushed to your project's repository are automatically picked and deployed to the Amazon EC2 instance by AWS Elastic Beanstalk. (You can watch the progress on your project dashboard.) Once you've seen how that works, start developing your own code, and have fun!
To run your tests locally, go to the root directory of the sample code and run
the python setup.py pytest command, which AWS CodeBuild also runs through
your buildspec.yml file.
To test your new code during the release process, modify the existing tests or add tests to the tests directory. AWS CodeBuild will run the tests during the build stage of your project pipeline. You can find the test results in the AWS CodeBuild console.
Learn more about AWS CodeBuild and how it builds and tests your application here: https://docs.aws.amazon.com/codebuild/latest/userguide/concepts.html
Learn more about AWS CodeStar by reading the user guide. Ask questions or make suggestions on our forum.
User Guide: https://docs.aws.amazon.com/codestar/latest/userguide/welcome.html Forum: https://forums.aws.amazon.com/forum.jspa?forumID=248
Best Practices: https://docs.aws.amazon.com/codestar/latest/userguide/best-practices.html?icmpid=docs_acs_rm_sec
To add AWS resources to your project, you'll need to edit the template.yml
file in your project's repository. You may also need to modify permissions for
your project's worker roles. After you push the template change, AWS CodeStar
and AWS CloudFormation provision the resources for you.
See the AWS CodeStar user guide for instructions to modify your template: https://docs.aws.amazon.com/codestar/latest/userguide/how-to-change-project.html#customize-project-template