feat: Semaine 8

Semaine_08/shopflow/order-service/.dockerignore

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+Dockerfile
+__pycache__
+*.pyc

Semaine_08/shopflow/order-service/Dockerfile

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+FROM python:3.12-slim
+
+WORKDIR /app
+
+RUN pip install fastapi uvicorn httpx
+
+COPY . .
+
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

Semaine_08/shopflow/order-service/circuit_breaker.py

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+import time
+
+class CircuitBreaker:
+    def __init__(self, failure_threshold: int = 3, recovery_timeout: int = 10) -> None:
+        self.failure_threshold = failure_threshold
+        self.recovery_timeout = recovery_timeout
+        self.failure_count = 0
+        self.last_failure_time = None
+        self.state = "CLOSED" # OPEN, CLOSED, HALF-OPEN
+
+    def call(self, function, *args, **kwargs):
+        if self.state == "OPEN" and self.last_failure_time is not None:
+            if time.time() - self.last_failure_time >= self.recovery_timeout:
+                self.state = "HALF-OPEN"
+            else:
+                raise Exception("Circuit is open")
+            
+        try:
+            result = function(*args, **kwargs)
+            self.on_success()
+            return result
+        except Exception as error: 
+            self.on_failure()
+            raise error
+
+    def on_success(self):
+        self.failure_count = 0
+        self.state = "CLOSED"
+
+    def on_failure(self):
+        self.failure_count += 1
+        self.last_failure_time = time.time()
+        if self.failure_count >= self.failure_threshold:
+            self.state = "OPEN"

Semaine_08/shopflow/order-service/main.py

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+import httpx
+from fastapi import FastAPI, HTTPException
+from pydantic import BaseModel
+
+from circuit_breaker import CircuitBreaker
+
+app = FastAPI()
+
+USER_SERVICE_URL = "http://user-service:8000"
+CATALOG_SERVICE_URL = "http://catalog-service:8000"
+
+orders_db = {}
+next_id = 1
+
+catalog_cb = CircuitBreaker(failure_threshold=3, recovery_timeout=10)
+
+class CreateOrderDTO(BaseModel):
+    user_id: int
+    product_id: int
+    quantity: int
+
+TIMEOUT = 5.0
+
+def get_product(product_id: int):
+    return catalog_cb.call(
+        httpx.get,
+        f"{CATALOG_SERVICE_URL}/products/{product_id}",
+        timeout=TIMEOUT
+        )
+
+@app.post("/orders", status_code=201)
+async def create_order(payload: CreateOrderDTO):
+    global next_id
+
+    user_response = httpx.get(f"{USER_SERVICE_URL}/users/{payload.user_id}")
+    try:
+        user_response = httpx.get(f"{USER_SERVICE_URL}/users/{payload.user_id}", timeout=TIMEOUT)
+    except httpx.TimeoutException:
+        raise HTTPException(status_code=503, detail="User service unavailable")
+    if user_response.status_code == 404:
+        raise HTTPException(status_code=404, detail="User not found")
+    
+    user = user_response.json()
+
+    try:
+        product_response = get_product(payload.product_id)
+    except httpx.TimeoutException:
+        raise HTTPException(status_code=503, detail="Catalog service unavailable")
+    if product_response.status_code == 404:
+        raise HTTPException(status_code=404, detail="Product not found")
+    
+    product = product_response.json()
+
+    try:
+        update_response = httpx.put(f"{CATALOG_SERVICE_URL}/products/{payload.product_id}/stock", json= {"quantity": payload.quantity}, timeout=TIMEOUT)
+    except httpx.TimeoutException:
+        raise HTTPException(status_code=503, detail="Catalog service unavailable")
+    if update_response.status_code == 400:
+        raise HTTPException(status_code= 400, detail= "Stock Insuffisant")
+    if update_response.status_code != 200:
+        raise HTTPException(status_code= 502, detail= "Erreur catalog-service")
+    
+    order_id = next_id
+    next_id += 1
+
+    new_order = {
+        "id": order_id,
+        "user_id": user["id"],
+        "user_name": user["name"],
+        "product_id": product["id"],
+        "product_name": product["name"],
+        "unit_price": product["price"],
+        "quantity": payload.quantity,
+        "total_price": product["price"] * payload.quantity
+    }
+
+    orders_db[order_id] = new_order
+    return new_order
+
+@app.get("/orders/{order_id}")
+async def get_order(order_id: int):
+    order = orders_db.get(order_id)
+    if not order:
+        raise HTTPException(status_code=404, detail="Order not found")
+    return order
+
+@app.get("/health")
+def health():
+    return {"status": "ok", "service": "order-service"}