AWS FastAPI Lambda API Gateway

This is a FastAPI application to be deployed as an Amazon Web Services (AWS) Lambda function, triggered via AWS API Gateway. This project is to be built and deployed using AWS CodePipeline.

For demonstration purposes, a simple Create Read Update Delete (CRUD) REST API has been created to perform actions against an AWS DynamoDB, the deployed lambda function IAM Role will need additional permissions when calling the operations defined.

The underlying infrastructure needed can be found within my Terraform terraform-aws-certified-devops-engineer-professional, alongside CloudFormation templates used to create other resources within my aws-cloudformation-playground.

Usage

1. Install python packages used for the service

   pip install -r requirements.txt

2. Run the FastAPI server, which will run on port 8000

   python app/main.py

   Alternatively, if you're within your [virtual environment]:

   uvicorn app.main:app --host 0.0.0.0 --port 8000

Endpoint documentation are available on http://127.0.0.1:8000/docs

Docker

Running the docker-compose.yml, will build a new image aws-fastapi-lambda-api-gateway-fastapi:latest which will be used for the fastapi service within the container.

docker-compose up -d

Note

Running the project via docker compose will on launch the lambda and is not the same as running the application via uvicorn. Will need to invoke the lambda by make a post request to the following URL: curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{REPLACE_WITH_EVENT_HERE}'

Tests

Unit tests are located in /tests/unit directory, run unit tests using:

pytest tests/unit

Additionally, a coverage report can be generated using pytest-cov:

pytest --cov=app tests/unit --cov-report=html:coverage_report

Will generate a coverage HTML file, in the /coverage_report/ directory, simply open the index.html in your chosen web browser.

Integration tests are located in /tests/integration directory, run integration using:

pytest tests/integration

Contributing

Git hook scripts are very helpful for identifying simple issues before pushing any changes. Hooks will run on every commit automatically pointing out issues in the code e.g. trailing whitespace.

To help with the maintenance of these hooks, pre-commit is used, along with pre-commit-hooks.

Please following these instructions to install pre-commit locally and ensure that you have run pre-commit install to install the hooks for this project.

Additionally, once installed, the hooks can be updated to the latest available version with pre-commit autoupdate.

GitHub Actions (CI/CD)

GitHub project has three workflow set up, found in .github/workflows/:

• '🧹 Run linter' (run-linter.yml): To run Flake8 and check Python code system and comply with various style guides.
• '🧪 Run unit tests' (run-unit-tests.yml): To run unit tests within a continuous integration (CI) environment, using pytest.