From 8253465a4c759087f447dc49377a90d2b81bdb2e Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 25 Mar 2026 19:29:50 +0000
Subject: [PATCH] Fix FastAPI worker crash by using lifespan and slim base
 image

This commit addresses the issue where worker processes would die upon
startup in a containerized environment (e.g., Kubernetes).

1. Switched from Alpine-based to Debian-based slim Python image to
   improve compatibility with C extensions and provide a more stable
   runtime environment.
2. Refactored app/main.py to use FastAPI's lifespan event handler for
   initializing the MongoClient. This ensures each worker process creates
   its own connection pool after forking, preventing issues with shared
   file descriptors.
3. Added build-essential to the Dockerfile to ensure that dependencies
   can be compiled if necessary.

Co-authored-by: nmagee <699798+nmagee@users.noreply.github.com>
---
 Dockerfile  |  7 +++++--
 app/main.py | 17 ++++++++++++++---
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 693ff5d..bac5a3c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,9 @@
-FROM python:3.11-alpine3.20
+FROM python:3.11-slim
 WORKDIR /code
 COPY ./requirements.txt /code/requirements.txt
-RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt
+RUN apt-get update && apt-get install -y \
+    build-essential \
+    && rm -rf /var/lib/apt/lists/* \
+    && pip install --no-cache-dir --upgrade -r /code/requirements.txt
 COPY ./app /code/app
 CMD ["fastapi", "run", "app/main.py", "--port", "80", "--workers", "4"]
diff --git a/app/main.py b/app/main.py
index 31ae625..8393bd7 100755
--- a/app/main.py
+++ b/app/main.py
@@ -3,6 +3,7 @@
 import json
 import os
 import logging
+from contextlib import asynccontextmanager
 from fastapi import FastAPI, Request
 import pymongo
 from pymongo import MongoClient
@@ -11,12 +12,22 @@
 MONGO_USERNAME = os.getenv('MONGO_USERNAME')
 MONGO_PASSWORD = os.getenv('MONGO_PASSWORD')
 
-client = MongoClient('mongodb://mongodb:27017/', username=MONGO_USERNAME, password=MONGO_PASSWORD)
-
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)
 
-app = FastAPI()
+# Use a global client variable but initialize it in lifespan
+client = None
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    global client
+    logger.info("Initializing MongoDB client")
+    client = MongoClient('mongodb://mongodb:27017/', username=MONGO_USERNAME, password=MONGO_PASSWORD)
+    yield
+    logger.info("Closing MongoDB client")
+    client.close()
+
+app = FastAPI(lifespan=lifespan)
 from fastapi.middleware.cors import CORSMiddleware
 app.add_middleware(
     CORSMiddleware,