amy-email-worker

A lambda worker for sending queued emails at scheduled times.

Repository structure

This repository doesn't follow typical project structure, so a word of explanation is required.

• cdk directory contains TypeScript code to deploy the worker to AWS Cloud.
• worker directory contains Python code (project).
• root directory contains main .gitignore, .pre-commit-config.yaml, license and readme
• .github contains CI/CD pipelines.

First steps (Python)

This project is for Python 3.12 version.

To work on Python code you should install Poetry.

Then you can create the Poetry environment:

$ cd worker/
$ poetry install

Important! Once Python dependencies are installed, you must install pre-commit configuration:

$ cd worker/
$ poetry shell
$ cd ..  # to root directory
$ pre-commit install

First steps (CDK)

This project is for Node 18 LTS version.

To work on CDK (Cloud Development Kit) for AWS Cloud you should install:

1. node JS (a suggested method is to use nvm)
2. cdk:

   $ cd cdk/
   $ npm install

Additionally you will probably want to set up your AWS CLI and credentials.

More instructions available in cdk/README.md file.

Python paths and modules

AWS lambda environment is specific when it comes to Python path management. For example, despite the code being in worker directory, lambda Python environment doesn't recognize worker module.

Therefore it's important to avoid using from worker.xyz import asd or import worker.utils, because this will not work. Instead, assume that the environment is stored in unnamed directory somewhere on a virtual machine, and you only have access to worker's submodules, like utils. Thus from utils.typing import Settings will work.

Testing lambda

Apart from unit tests, you can deploy the lambda to the staging environment and test it in AWS web console.

To deploy lambda use CDK:

$ cd cdk/
$ cdk deploy EmailWorkerLambdaStaging

Warning: this circumvents the CI/CD pipeline.