build: add postgresql db config (with sqlalchemy) (#20)

* Install psycopg2 & sqlalchemy dependencies

* Setup DB

* Connect to DB on startup

* Update documentation

* Remove .env.example file, simplify setup

.env.example → .env

@@ -15,3 +15,10 @@ SENTRY_DNS=
 
 # Log level to use, DEBUG by default in dev
 LOG_LEVEL=DEBUG
+
+# Postgres database
+POSTGRES_DB_NAME=postgres
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=postgres
+POSTGRES_HOST=localhost
+POSTGRES_PORT=5432

.gitignore

@@ -109,9 +109,6 @@ ENV/
 env.bak/
 venv.bak/
 
-# Environment variables
-.env
-
 # Spyder project settings
 .spyderproject
 .spyproject

INSTALL.md

@@ -3,10 +3,12 @@
 ## Prerequisites
 
 - Python 3.10 (lower version may be OK, but untested)
-- pip
+- PostgreSQL 13 (lower version may be OK, but untested)
 
 ## Setup
 
+### Without Docker
+
 ```
 # clone repo
 git clone https://github.com/openfoodfacts/open-prices.git
@@ -21,11 +23,12 @@ source venv/bin/activate
 
 # install
 pip install -r requirements.txt
-
-# environment variables
-# make a copy of *.env.example* and rename it to *.env*
 ```
 
+### With Docker
+
+TODO
+
 ## Run locally
 
 ```

README.md

@@ -4,8 +4,9 @@ A REST API designed to interact with the Open Food Facts _Open Prices_ database.
 
 ## Dependencies
 
-* Python 3.12
+* Python 3.10
 * [FastAPI](https://fastapi.tiangolo.com/) framework
+* PostgreSQL database
 
 ## How to install on your local machine
 

app/api.py

@@ -8,8 +8,10 @@
 from openfoodfacts.utils import get_logger
 
 from app.config import settings
+from app.db import session
 from app.utils import init_sentry
 
+
 logger = get_logger(level=settings.log_level.to_int())
 
 description = """
@@ -32,6 +34,17 @@
 init_sentry(settings.sentry_dns)
 
 
+@app.on_event("startup")
+async def startup():
+    global db
+    db = session()
+
+
+@app.on_event("shutdown")
+async def shutdown():
+    db.close()
+
+
 @app.get("/", response_class=HTMLResponse)
 def main_page(request: Request):
     return templates.TemplateResponse(

app/config.py

@@ -1,6 +1,7 @@
 from enum import Enum
 
 from pydantic_settings import BaseSettings
+from pydantic_settings import SettingsConfigDict
 
 
 class LoggingLevel(Enum):
@@ -27,8 +28,15 @@ def to_int(self):
 
 
 class Settings(BaseSettings):
+    postgres_db_name: str
+    postgres_user: str
+    postgres_password: str
+    postgres_host: str
+    postgres_port: int = 5432
     sentry_dns: str | None = None
     log_level: LoggingLevel = LoggingLevel.INFO
 
+    model_config = SettingsConfigDict(env_file=".env", extra="ignore")
+
 
 settings = Settings()

app/db.py

@@ -0,0 +1,19 @@
+from sqlalchemy import create_engine
+from sqlalchemy.engine import URL
+from sqlalchemy.orm import sessionmaker
+
+from app.config import settings
+
+
+url = URL.create(
+    drivername="postgresql",
+    database=settings.postgres_db_name,
+    username=settings.postgres_user,
+    password=settings.postgres_password,
+    host=settings.postgres_host,
+    port=settings.postgres_port,
+)
+
+engine = create_engine(url)
+
+session = sessionmaker(autocommit=False, autoflush=False, bind=engine)

requirements.txt

@@ -1,8 +1,9 @@
 fastapi==0.103.1
 jinja2==3.1.2
 openfoodfacts==0.1.10
-peewee==3.17.0
+psycopg2-binary==2.9.9
 pydantic-settings==2.0.3
 requests==2.31.0
 sentry-sdk[fastapi]==1.31.0
+sqlalchemy==2.0.23
 uvicorn==0.23.2