Azure Web App部署出现503错误，但Flask应用本地运行正常

已成功将GitHub仓库中的Flask应用部署到Azure Web App，本地通过GitHub Codespace运行完全正常，但访问Azure Web App分配的域名时出现503服务不可用错误。

已知情况 #

• Azure门户显示部署成功
• 该Python Flask应用包含存放在GitHub仓库中的若干大型模型
• 本地运行无任何问题
• 已反复检查日志，但未找到能解释Azure上应用不可用的相关错误

Flask应用代码 #

from flask import Flask, request, jsonify
import numpy as np
import tensorflow as tf
import joblib
import os  # Required to access environment variables

# Initialize the Flask app
app = Flask(__name__)

# Get the API key from environment variables
api_key = os.getenv('API_KEY')

# Load models and scalers
def load_models():
    my code

# Preload the models and scalers
load_models()

@app.route('/predict', methods=['POST'])
def predict():
    my code

# Run the Flask app
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

requirements.txt内容 #

Flask==2.2.5
numpy==1.26.4
tensorflow==2.17.0
joblib==1.4.2
requests==2.32.3
pyngrok==7.2.0

已尝试的操作 #

• 确认Flask应用本地运行无问题
• 使用Azure内置部署工具直接从GitHub部署到Azure Web App
• 验证Azure中的设置（如App Service Plan、环境变量、启动命令）
• 检查Azure服务器日志，但未找到指向503错误原因的信息

部分日志内容 #

2024-09-30T21:09:24.703Z ERROR - Container esraafactory_0_ed1d428d for site esraafactory did not start within expected time limit. Elapsed time = 232.319653 sec
2024-09-30T21:09:25.013Z ERROR - Container esraafactory_0_ed1d428d didn't respond to HTTP pings on port: 8000, failing site start. See container logs for debugging.
2024-09-30T21:09:25.304Z INFO  - Stopping site esraafactory because it failed during startup.
2024-09-30T21:09:31.0708108Z Container is terminating. Grace period: 0 seconds.
2024-09-30T21:09:31.2297871Z Stop and delete container. Retry count = 0
2024-09-30T21:09:31.2395158Z Stopping container: esraafactory_kudu_c75f8eb4.
2024-09-30T21:09:32.3659006Z Deleting container: esraafactory_kudu_c75f8eb4. Retry count = 0
2024-09-30T21:09:33.6837850Z Container spec TerminationMessagePolicy  path
2024-09-30T21:09:33.6940792Z Container is terminated. Total time elapsed: 2612 ms./home/LogFiles/2024_10_01_lw0ldlwk0003P0_default_docker.log
2024-10-01T14:10:25.652152756Z           ^^^^^^^^^^^^^^^^
2024-10-01T14:10:25.652157156Z   File "/opt/python/3.12.2/lib/python3.12/pickle.py", line 1205, in load
2024-10-01T14:10:25.652163656Z     dispatch[key[0]](self)
2024-10-01T14:10:25.652168056Z     ~~~~~~~~^^^^^^^^
2024-10-01T14:10:25.652172557Z KeyError: 118
2024-10-01T14:10:25.652176957Z [2024-10-01 14:10:25 +0000] [95] [INFO] Worker exiting (pid: 95)
2024-10-01T14:10:27.664242936Z [2024-10-01 14:10:27 +0000] [87] [ERROR] Worker (pid:95) exited with code 3
2024-10-01T14:10:27.664777951Z [2024-10-01 14:10:27 +0000] [87] [ERROR] Shutting down: Master
2024-10-01T14:10:27.664806952Z [2024-10-01 14:10:27 +0000] [87] [ERROR] Reason: Worker failed to boot./home/LogFiles/2024_10_01_lw0ldlwk0003P0_docker.log
2024-10-01T14:08:54.561Z INFO  - docker run -d --expose=8000 --name esraafactory_0_bc140daf -e WEBSITE_USE_DIAGNOSTIC_SERVER=false -e WEBSITE_SITE_NAME=EsraaFactory -e WEBSITE_AUTH_ENABLED=False -e WEBSITE_ROLE_INSTANCE_ID=0 -e WEBSITE_HOSTNAME=esraafactory-e3dugrg8cqfsdsbj.westeurope-01.azurewebsites.net -e WEBSITE_INSTANCE_ID=59be3e435403af8aafd67963991260c0f723c0cdf77e39cf7540425bb7018979 appsvc/python:3.12_20240619.2.tuxprod
2024-10-01T14:08:54.561Z INFO  - Logging is not enabled for this container.Please use linux-diagnostics to enable logging to see container logs here.
2024-10-01T14:08:55.343Z INFO  - Initiating warmup request to container esraafactory_0_bc140daf for site esraafactory
2024-10-01T14:09:25.913Z INFO  - Waiting for response to warmup request for container esraafactory_0_bc140daf. Elapsed time = 30.5700783 sec
2024-10-01T14:09:41.084Z INFO  - Waiting for response to warmup request for container esraafactory_0_bc140daf. Elapsed time = 45.7410913 sec
2024-10-01T14:09:56.272Z INFO  - Waiting for response to warmup request for container esraafactory_0_bc140daf. Elapsed time = 60.9289723 sec
2024-10-01T14:10:28.298Z ERROR - Container esraafactory_0_bc140daf for site esraafactory has exited, failing site start
2024-10-01T14:10:28.305Z ERROR - Container esraafactory_0_bc140daf didn't respond to HTTP pings on port: 8000, failing site start. See container logs for debugging.
2024-10-01T14:10:28.310Z INFO  - Stopping site esraafactory because it failed during startup./home/LogFiles/AppServiceAppLogs_Feature_Installer/startup_0.log
2024-09-30 21:19:37,159  [MainThread] [DEBUG] : Initialized AppServiceAppLogging
2024-09-30 21:23:06,855  [MainThread] [DEBUG] : Initializating AppServiceAppLogging
2024-09-30 21:23:06,856  [Thread-1 (] [DEBUG] : Did not find any previously bound socket
2024-09-30 21:23:06,856  [MainThread] [DEBUG] : Initialized AppServiceAppLogging
2024-10-01 13:45:13,324  [MainThread] [DEBUG] : Initializating AppServiceAppLogging
2024-10-01 13:45:13,348  [Thread-1 (] [DEBUG] : Did not find any previously bound socket
2024-10-01 13:45:13,348  [MainThread] [DEBUG] : Initialized AppServiceAppLogging
2024-10-01 14:09:56,887  [MainThread] [DEBUG] : Initializating AppServiceAppLogging
2024-10-01 14:09:56,888  [Thread-1 (] [DEBUG] : Did not find any previously bound socket

需求 #

希望Azure Web App域名能正常访问Flask应用，如同本地环境一样。503错误表明应用服务响应异常，但无法从现有日志中定位问题，恳请提供排查建议。

内容的提问来源于stack exchange，提问作者Lara Mamdouh