Migrate from Flask to FastAPI with redis

inventory-service/Dockerfile

@@ -17,4 +17,4 @@ COPY . .
 EXPOSE 7000
 
 # Run the application
-CMD ["python", "app.py"]
+CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "7000"]

inventory-service/app.py

@@ -1,103 +1,134 @@
-from flask import Flask, jsonify, request
-from flask_sqlalchemy import SQLAlchemy
-from flask_caching import Cache
-import lorem
-import random 
-
-app = Flask(__name__)
-app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://postgres:password@db2:5432/inventory_db'
-app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
-
-# Configure Redis caching
-app.config['CACHE_TYPE'] = 'redis'
-app.config['CACHE_REDIS_URL'] = 'redis://caching-db:6379/0'
-cache = Cache(app)
-cache.init_app(app)
-
-db = SQLAlchemy(app)
-
-
-class Product(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    name = db.Column(db.String(100), unique=True)
-    price = db.Column(db.Float)
-    description = db.Column(db.String(500))
-
-    def __init__(self, name, price, description):
-        self.name = name
-        self.price = price
-        self.description = description
-
-
-@cache.cached()
-@app.route('/products', methods=['GET'])
-def get_all_products():
-    products = Product.query.all()
+from fastapi import FastAPI, Query, Depends, HTTPException
+from sqlalchemy import create_engine, Column, Float, Integer, String
+from sqlalchemy.orm import sessionmaker, declarative_base
+from aioredis import create_redis_pool
+import random, lorem, json
+
+app = FastAPI()
+
+# Database configuration
+database_url = 'postgresql://postgres:password@db2:5432/inventory_db'
+engine = create_engine(database_url)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+Base = declarative_base()
+
+# Redis caching configuration
+redis_url = 'redis://caching-db:6379/0'
+redis = None
+
+# Dependency to get a database session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+# Product model
+class Product(Base):
+    __tablename__ = 'products'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(100), unique=True)
+    price = Column(Float)
+    description = Column(String(500))
+
+# Create database tables
+Base.metadata.create_all(bind=engine)
+
+# Add dummy product data
+db = SessionLocal()
+for i in range(1, 101):
+    name = f'Product_{i}'
+    price = round(random.uniform(1.99, 999.99), 2)
+    description = lorem.get_sentence(count=2)
+    product = Product(name=name, price=price, description=description)
+    db.add(product)
+db.commit()
+db.close()
+
+# Set up Redis connection
+@app.on_event("startup")
+async def startup_event():
+    global redis
+    redis = await create_redis_pool(redis_url)
+
+# Shutdown Redis connection
+@app.on_event("shutdown")
+async def shutdown_event():
+    global redis
+    redis.close()
+    await redis.wait_closed()
+
+# API endpoints
+@app.get('/products')
+async def get_all_products(db = Depends(get_db)):
+    products = await redis.get('products')
+    if products:
+        return json.loads(products)
+
+    products = db.query(Product).all()
     result = []
     for product in products:
         result.append({
             'name': product.name,
             'price': product.price,
             'description': product.description
         })
-    return jsonify(result)
+    await redis.set('products', json.dumps(result))
 
+    return result
 
-@cache.cached(timeout=50)
-@app.route('/products/<name>', methods=['GET'])
-def get_product_by_name(name):
-    product = Product.query.filter_by(name=name).first()
-    if product:
-        return jsonify({
-            'name': product.name,
-            'price': product.price,
-            'description': product.description
-        })
-    else:
-        return jsonify({'message': 'Product not found'}), 404
-
+@app.get('/products/search')
+async def search_product(keyword: str = Query(..., min_length=1), db = Depends(get_db)):
+    result = await redis.get(keyword)
+    if result:
+        return json.loads(result)
 
-@app.route('/products/search', methods=['GET'])
-def search_product():
-    keyword = request.args.get('keyword')
-    products = Product.query.filter(Product.name.ilike(f'%{keyword}%')).all()
+    products = db.query(Product).filter(Product.name.ilike(f'%{keyword}%')).all()
     result = []
     for product in products:
         result.append({
             'name': product.name,
             'price': product.price,
             'description': product.description
         })
-    return jsonify(result)
+    await redis.set(keyword, json.dumps(result))
 
+    return result
 
-@app.route('/products/price-range', methods=['GET'])
-def get_products_by_price_range():
-    min_price = float(request.args.get('min_price'))
-    max_price = float(request.args.get('max_price'))
-    products = Product.query.filter(Product.price.between(min_price, max_price)).all()
+@app.get('/products/price-range')
+async def get_products_by_price_range(min_price: float = Query(...), max_price: float = Query(...), db = Depends(get_db)):
+    result = await redis.get(f'{min_price}_{max_price}')
+    if result:
+        return json.loads(result)
+
+    products = db.query(Product).filter(Product.price.between(min_price, max_price)).all()
     result = []
     for product in products:
         result.append({
             'name': product.name,
             'price': product.price,
             'description': product.description
         })
-    return jsonify(result)
-
+    await redis.set(f'{min_price}_{max_price}', json.dumps(result))
 
-if __name__ == '__main__':
-    # Create database tables
-    with app.app_context():
-        db.create_all()
+    return result
 
-        # Add dummy product data
-        for i in range(1, 101):
-            name = f'Product {i}'
-            price = round(random.uniform(1.99, 999.99), 2)
-            description = lorem.get_sentence(count=2)
-            product = Product(name, price, description)
-            db.session.add(product)
-            db.session.commit()
+@app.get('/products/{name}')
+async def get_product_by_name(name: str, db = Depends(get_db)):
+    product = await redis.get(name)
+    if product:
+        return json.loads(product)
 
-    app.run(host='0.0.0.0', port=7000)
+    product = db.query(Product).filter_by(name=name).first()
+    if product:
+        result = {
+            'name': product.name,
+            'price': product.price,
+            'description': product.description
+            }
+        await redis.set(name, json.dumps(result))
+        return result
+    else:
+        raise HTTPException(status_code=404, detail='Product not found')