python-lambda-template

A template repository for creating Python lambda functions.

Repo Setup (delete this section and above after initial function setup)

1. Rename "my_function" to the desired initial function name across the repo. (May be helpful to do a project-wide find-and-replace).
2. Update Python version if needed (note: AWS lambda cannot currently support versions higher than 3.9).
3. Install all dependencies with make install to create initial Pipfile.lock with latest dependency versions.
4. Add initial function description to README and update initial required ENV variable documentation as needed.
5. Update license if needed (check app-specific dependencies for licensing terms).
6. Check Github repository settings:
   • Confirm repo branch protection settings are correct (see dev docs for details)
   • Confirm that all of the following are enabled in the repo's code security and analysis settings:
     • Dependabot alerts
     • Dependabot security updates
     • Secret scanning
7. Create a Sentry project for the app if needed (we want this for most apps):
   • Send initial exceptions to Sentry project for dev, stage, and prod environments to create them.
   • Create an alert for the prod environment only, with notifications sent to the appropriate team(s).
   • If not using Sentry, delete Sentry configuration from my_function.py and test_my_function_.py, and remove sentry_sdk from project dependencies.

my_function

Description of the function/functions.

Development

• To preview a list of available Makefile commands: make help
• To install with dev dependencies: make install
• To update dependencies: make update
• To run unit tests: make test
• To lint the repo: make lint

Running Locally with Docker

https://docs.aws.amazon.com/lambda/latest/dg/images-test.html

• Build the container:

  docker build -t my_function:latest .

• Run the default handler for the container:

  docker run -e WORKSPACE=dev -p 9000:8080 my_function:latest

• Post to the container:

  curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'

• Observe output:

  "You have successfully called this lambda!"
  

Running a Specific Handler Locally with Docker

If this repo contains multiple lambda functions, you can call any handler you copy into the container (see Dockerfile) by name as part of the docker run command:

docker run -p 9000:8080 my_function:latest lambdas.<a-different-module>.lambda_handler

Environment Variables

Required

SENTRY_DSN=### If set to a valid Sentry DSN, enables Sentry exception monitoring. This is not needed for local development.
WORKSPACE=### Set to `dev` for local development, this will be set to `stage` and `prod` in those environments by Terraform.

Optional

Delete this section if it isn't applicable to the PR.

<OPTIONAL_ENV>=### Description for optional environment variable