A FastAPI sample

It's a FastAPI implementation as the backend for a blog system. This project's a funny goal to apply things that I'm learning. Things that you see here like telemetry using open source projects, CRUD using REST, and GraphQL (I hope that I have time to do that).

Dependencies

Poetry
SQLAlmechy
Alembic for migrations
OpenTelemtry for instrumentation
Docker
Docker-Compose
Jaeger
Next.js
React
Make

How to use

Use make command to run inside a docker container, it'll expose the port 8000 and access using URL: http://localhost:8000. I'm not sure if a makefile runs in the Powershell, probably yes but I suggest using WSL2.

The frontend is in the early stage but you can see access: http://localhost:3000/.

Up and run:

make dev-up

This repo is instrumented by OpenTelemtry and export metric to Jaeger that starts together with the app by Docker-Compose, to access: http://localhost:16686/

Tests

To run tests will up a PostgreSQL container and expose 5433 port to populate. The report will write in htmlcov dir.

make test-app

Run and watch on the Jaeger things breaking

The FastAPI code here was OpenTelemetry instrumented and to export Traces to Jaeger. If you want to see a break simulation, follow the steps below.

Install dependencies

python -m venv .venvpip install poetrypoetry install

Start FastAPI, PostgreSQL and Jaeger

make dev-up

Open another shell session and run `populate_posts.py` to create users and posts samples.

opentelemetry-instrument tests/populate_posts.py

Break things

Open a third shell session to stop Postgres, this will break the FastAPI app. You'll see error messages in the log and the script client on the console. Stop Postgres, wait some seconds or a minute, start Postgres again.

make dev-db-killsleep 30make dev-db-start

Stop populate script

Stop the populate_posts.py scritpt (ctrl+c), go to Jaeger UI (http://localhost:16686/). If everything fine (or fail... 😁), you'll see on Jaeger like screenshots below.