无法使用 flask 服务器在 IIS 上运行 dash 应用程序

Question

我的 IIS（Windows Server 2016）上有两个网站（都使用 Dash 和 Flask）。

第一个是由 app.py 和 web.config 组成的最小工作示例。 因为不知何故，我无法让第二个站点正常工作。 在两个示例下方，并附有错误消息。

1 个工作示例

FastCGI 设置：

• PYTHONPATH: C:\inetpub\wwwroot\mvp
• WSGI_HANDLER：app.server

应用程序.py

 import flask import dash import dash_core_components as dcc import dash_html_components as html server = flask.Flask(__name__) app = dash.Dash(__name__, server=server) app.layout = html.Div(children=[ html.H1(children='Hello Dash'), html.Div(children=''' Dash: A web application framework for Python. '''), dcc.Graph( id='example-graph', figure={ 'data': [ {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'}, {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': 'Montreal'}, ], 'layout': { 'title': 'Dash Data Visualization' } } ) ]) if __name__ == '__main__': app.run_server(debug=True)

web.config

 <?xml version="1.0" encoding="UTF-8"?> <configuration> <system.webServer> <handlers> <add name="FlaskHandler" path="*" verb="*" modules="FastCgiModule" scriptProcessor="C:\ProgramData\Anaconda3\envs\mvp\python.exe|C:\ProgramData\Anaconda3\envs\mvp\Lib\site-packages\wfastcgi.py" resourceType="Unspecified" /> </handlers> </system.webServer> </configuration>

2 失败的例子

FastCGI 设置：

• PYTHONPATH: C:\inetpub\wwwroot\testsite
• WSGI_HANDLER：dashapp.server

 -flaskapp - __init__.py - auth.py - database_models.py - email_sending.py - main.py --templates - base.html - index.html - login.html - dashapp.py - web.config

烧瓶应用程序

 # __init__.py """ Set up for the FLASK app, Database, basic login and Integrating the Dash app -> Main file to run the Flask app is in the dashapp.py file """ from flask import Flask from flask_sqlalchemy import SQLAlchemy from flask_login import LoginManager import dash from flask.helpers import get_root_path from flask_login import login_required # setup Dash ########################################################################################################### def register_dashapps(app): # get the Dash app files from flaskapp.dashapp_searchtool.layout import layout from flaskapp.dashapp_searchtool.callbacks import register_callbacks # Meta tags for viewport responsiveness meta_viewport = {"name": "viewport", "content": "width=device-width, initial-scale=1, shrink-to-fit=no"} external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css'] # base url, needed for login_requiered this url needs to end with / in dash base_url = '/searchtool/' # initialize dash app and bind server=app to the flask server dashapp_searchtool = dash.Dash(__name__, server=app, url_base_pathname=base_url, assets_folder=get_root_path(__name__) + r'\dashapp_searchtool\assets', meta_tags=[meta_viewport], external_stylesheets=external_stylesheets) # set up the dash app layout and content with app.app_context(): dashapp_searchtool.title = 'Search Tool' dashapp_searchtool.layout = layout register_callbacks(dashapp_searchtool) # protect the dash app url, to only be called when logged in _protect_dashviews(dashapp_searchtool, base_url) # lock the dash app, only works when user login is is given. # WORKAROUND because the in the example given version with dashapp.url_base_pathname doesnt work def _protect_dashviews(dashapp, base_url): for view_func in dashapp.server.view_functions: if view_func.startswith(base_url): dashapp.server.view_functions[view_func] = login_required(dashapp.server.view_functions[view_func]) # Setup Flask and Databse connection ################################################################################### app = Flask(__name__) #secret key good for anything with authentifictations... app.config['SECRET_KEY'] = 'xxx' app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite' # init SQLAlchemy so we can use it later in our models with. db db = SQLAlchemy(app) # Set up Dash connection ############################################################################################### register_dashapps(app) # handle user login pre setup from the flask_login package ############################################################# login_manager = LoginManager() # If someone is not logged in redirect to login login_manager.login_view = 'auth.login' login_manager.init_app(app) from.database_models import User # uses cookie to save logged in user with a user_id and can recheck if user is in database @login_manager.user_loader def load_user(user_id): # since the user_id is just the primary key of our user table, use it in the query for the user return User.query.get(int(user_id)) # blueprint for auth routes in our app for login, logout and sing in from.auth import auth as auth_blueprint app.register_blueprint(auth_blueprint) # blueprint for non-auth parts of app for profile and main from.main import main as main_blueprint app.register_blueprint(main_blueprint)

dashapp.py

 # Run this file to run Dash App with entire flask login project from flaskapp import app server = app if __name__ == '__main__': server.run(debug=True)

web.config

 <?xml version="1.0" encoding="UTF-8"?> <configuration> <system.webServer> <handlers> <add name="FlaskH2" path="*" verb="*" modules="FastCgiModule" scriptProcessor="C:\ProgramData\Anaconda3\envs\dash_search_app\python.exe|C:\ProgramData\Anaconda3\envs\dash_search_app\Lib\site-packages\wfastcgi.py" resourceType="Unspecified" /> </handlers> </system.webServer> </configuration>

在本地，如果我执行 python dashapp.py 一切正常。 但是通过访问绑定的 URL 我收到以下错误：

 Error occurred while reading WSGI handler: Traceback (most recent call last): File "C:\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\wfastcgi.py", line 791, in main env, handler = read_wsgi_handler(response.physical_path) File "C:\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\wfastcgi.py", line 633, in read_wsgi_handler handler = get_wsgi_handler(os.getenv("WSGI_HANDLER")) File "C:\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\wfastcgi.py", line 616, in get_wsgi_handler raise ValueError('"%s" could not be imported%s' % (handler_name, last_tb)) ValueError: "dashapp.server" could not be imported: Traceback (most recent call last): File "C:\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\wfastcgi.py", line 600, in get_wsgi_handler handler = __import__(module_name, fromlist=[name_list[0][0]]) File ".\dashapp.py", line 3, in from flaskapp import app File ".\flaskapp\__init__.py", line 67, in register_dashapps(app) File ".\flaskapp\__init__.py", line 19, in register_dashapps from flaskapp.dashapp_searchtool.layout import layout File ".\flaskapp\dashapp_searchtool\layout.py", line 30, in import pandas as pd File "C:\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\pandas\__init__.py", line 17, in "Unable to import required dependencies:\n" + "\n".join(missing_dependencies) ImportError: Unable to import required dependencies: numpy: IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE. Importing the numpy c-extensions failed. - Try uninstalling and reinstalling numpy, - If you have already done that: then. 1. Check that you expected to use Python3:7 from "C.\ProgramData\Anaconda3\envs\dash_search_app\python,exe". and that you have no directories in your PATH or PYTHONPATH that can interfere with the Python and numpy version "1.17.3" you're trying to use. 2, If (1) looks fine: you can open a new issue at https.//github.com/numpy/numpy/issues: Please include details on, - how you installed Python - how you installed numpy - your operating system - whether or not you have multiple versions of Python installed - if you built from source, your compiler versions and ideally a build log - If you're working with a numpy git repository. try `git clean -xdf` (removes all files not under version control) and rebuild numpy: Note, this error has many possible causes. so please don't comment on an existing issue about this - open a new one instead: Original error was: DLL load failed. The specified module could not be found: StdOut: StdErr: C.\ProgramData\Anaconda3\envs\dash_search_app\lib\site-packages\flask_sqlalchemy\__init__:py:794: FSADeprecationWarning. SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future. Set it to True or False to suppress this warning.

Answer 1

我刚刚发现 Python 3.7 与 wfastcgi 不兼容。

降级环境 tp Pyython 3.6 是解决方案。

Answer 2

我通过授予 IIS 站点访问 numpy 所依赖的 dll 的权限找到了解决方案。 适用于 python 3.8（也可能是 3.7）。 我的解决方案发布在这里

Deploying Python Flask Application on IIS with wfastcgi in Python 3.7+ with Numpy, Pandas, etc