fastapi_docker

Hobby project - backend for simple TODO list app hosted on AWS cloud

🗂️ Multitenancy

Based on Multitenancy with FastAPI, SQLAlchemy and PostgreSQL

Main differences: Alembic behavior. All tables are created using migrations. Each tenant schema has his own alembic_version table with information about current migration revision.

🌊 Workflow

FastAPI runs on each startup migration d6ba8c13303e (create default Tables in PG public schema if not exists)
- Can be run manual: alembic -x tenant=public upgrade d6ba8c13303e
Create new schema (ex: a) and store information about it: ``GET /create?name=a&schema=a&host=a`
Apply all migrations: GET /upgrade?schema=a
- manual test alembic -x dry_run=True -x tenant=a upgrade head
- Manual run: alembic -x tenant=a upgrade head

There is a /cc/ group of endpoints which allows to:

get list of all tenants
run migration for single tenant
run migrations for all tenants

⚠️ Important - after adding a new migration rebuild of docker image is required (to copy new migration)

Alembic

Auto generating migrations (❌ - please, don't use it in this project!)

alembic revision --autogenerate -m "Add description"

Manual generating migrations (✅ - yes, please ☺️)

alembic revision -m "Add manual change"

Execute All Migrations ⏩:

alembic upgrade head

Migration Rollback ↩️ (by one step)

alembic downgrade -1

🧪 Tests

Right now, manual clean-up is required after each test:

DELETE FROM public.public_users 
WHERE email LIKE 'faker_000_%';

DELETE FROM public.public_companies  
WHERE city  LIKE 'faker_000_%';

DROP SCHEMA IF EXISTS "fake_tenant_company_for_test_00000000000000000000000000000000" CASCADE;

To run tests locally in VS Code export environment variable first:

export DB_HOST=localhost DB_PORT=5432 DB_DATABASE=pg_db DB_USERNAME=postgres DB_PASSWORD=postgres

Test execution (with code coverage):

(.venv) fastapi-multitenant-example-app$ coverage run -m pytest -v tests && coverage report -m

coverage html

WIP: SQLAlchemy 2.0

Running outside docker:

export PYTHONPATH=$PWD
export DB_HOST=database.url
export DB_USERNAME=postgres
(...rest of DB env)


SQLALCHEMY_WARN_20=1 python -W always::DeprecationWarning ./app/main.py

🏋️‍♂️Load test

siege --concurrent=20 --reps=5 --header="tenant:bakery_ad094154c48" --header="Authorization:Bearer 123456" https://url.com/users/

ab -k -c 100 -n 5000 -H "tenant:polski_koncern_naftowy_orlen_fc26bff5f7b540d9b8d6bc68382e97a0" -H "Authorization:Bearer 24cd13a1bbf07d0cab6dcfd93ca9a1e04a339c880db21eeeeae108d6b0555cf5460ff0fa4818a41b5f125ec00e924b61c6d64f2de18c95114962120f581e7960" -v 1 https://api.url.pl/users/

Results:

Uvicorn, Debug

param	value
transactions	200
availability	100.00
elapsed_time	8.66
data_transferred	0.09
response_time	0.79
transaction_rate	23.09
throughput	0.01
concurrency	18.35
successful_transactions	200
failed_transactions	0
longest_transaction	3.18
shortest_transaction	0.16

alanlv / fastapi_docker