Homework

Story

The first thing that comes to my mind when I hear "micro-service" is an AWS Lambda.

I worked for a few good years with this wonderful framework called Chalice - https://aws.github.io/chalice/index.html. This is a python framework. I did a lot of research regarding these cloud frameworks and I think this one is the best. Sam (TS framework) is way too heavy, Zappa took me a while to understand and as for Stateless (a JS/TS framework), well, from my personal experience kinda sux (sorry for my language).

At first I thought to do it all using Redis as my database, just for fun, but eventually I went with Postgres. It's an amazingly powerful relational database and I saw it fit here.

Arch.

So I approached it like so:

First I bootstrapped a new project and populated all the methods. (app.py)
Then I wrapped for the database connection (chalicelib/conn.py)
After that I created the SQL scheme, all needed stored procedures and some population data.
Lastly, I created some tests to optimistically check all the cases.

I also added a small .travis.yml file for some initial CI.

Run

To run the project locally, install the dev and regular requirements and simply run the following:

docker run -p 5432:5432 -d -e POSTGRES_USER="user" -e POSTGRES_PASSWORD="pass" -e POSTGRES_DB="db" -v /tmp/pg-data:/var/lib/postgresql/data --name pg postgres
docker exec -i pg psql postgresql://user:pass@0.0.0.0:5432/db < scheme.sql

This will run a local Postgres DB and populate it with data

chalice local

Or simply docker compose up -d

Deploy

There should be a one-time configuration of the .chalice/config.json file, to set the ENV variables for production.

To deploy from the main branch (having sufficient AWS credentials) just run:

chalice deploy

Contribute

After any change you can run py.test tests/test_app.py from the root of the project to run all the tests. If adding more functionality, please add more tests.

Notes

I believe in a clean code which leads to no doubts of what it does, so I spared myself some comments. Usually after reviews of my PR's I add comments if I see anyone struggling to understand something.
I implemented the password check using a simple query. I understand there should have been some bcrypt or scrypt, but it's a bit of a mess deploying binaries from MacOS to Linux. I usually do a deployment docker for this, but I thought it'd be an overkill here.