部署在 apache 服务器上的 Dash 失败 "Dash object not callable"

Question

我正在尝试将 python dash 应用程序部署到我的 apache 服务器。我遵循了我能找到的有关此配置的少量信息 (officials docs; this troubleshooting thread was a bit better)。当我访问该网站时，页面 returns 变成 500 Internal Server Error，在服务器错误日志中被描述为 "Dash object not callable"。这些是配置文件：

>> cat /var/www/html/wsgi/dashGAF.wsgi
#!/usr/bin/python
import sys
sys.path.insert(0,"/home/ubuntu/dashboards/")
from dashGAF import app as application

>> cat /etc/apache2/sites-available/dash.conf 
WSGIDaemonProcess dashGAF user=ubuntu group=ubuntu home=/home/ubuntu threads=5
WSGIScriptAlias /dashGAF /var/www/html/wsgi/dashGAF.wsgi
    <Directory /home/ubuntu/dashboards>
        WSGIProcessGroup dashGAF
            WSGIApplicationGroup %{GLOBAL}
            WSGIScriptReloading On
        Require all granted
    </Directory>

>> cat dashGAF.py
# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets, routes_pathname_prefix='/dashGAF/')
server = app.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': u'Montréal'},
            ],
            'layout': {
                'title': 'Dash Data Visualization'
            }
        }
    )
])

if __name__ == '__main__':
    app.run_server(debug=True, host='0.0.0.0')

当我在 the_ip_address/dashGAF 访问我的 dash 应用程序时，我得到一个 500 Internal Server Error。检查 error.log 我看到：

[Sat Jun 20 04:42:59.502528 2020] [wsgi:error] [pid 6064:tid 140622992238336] [client 118.210.193.245:50042] mod_wsgi (pid=6064): Exception occurred processing WSGI script '/var/www/html/wsgi/dashGAF.wsgi'.
[Sat Jun 20 04:42:59.502675 2020] [wsgi:error] [pid 6064:tid 140622992238336] [client 118.210.193.245:50042] TypeError: 'Dash' object is not callable

如果能帮助解决这个问题，我们将不胜感激！此外，任何有关更改配置文件的建议都会有所帮助。

更多细节：

我收到模块导入错误，例如我的 /var/log/apache2/error.log 中的以下内容：

[Sat Jun 20 03:38:58.556219 2020] [wsgi:error] [pid 583:tid 140297735726848] [client 118.210.193.245:55574]   File "/home/ubuntu/dashboards/dashGAF.py", line 2, in <module>
[Sat Jun 20 03:38:58.556265 2020] [wsgi:error] [pid 583:tid 140297735726848] [client 118.210.193.245:55574]     import dash
[Sat Jun 20 03:38:58.556285 2020] [wsgi:error] [pid 583:tid 140297735726848] [client 118.210.193.245:55574] ImportError: No module named dash

我可以通过 sudo pip install dash==1.13.2.

修复

我制作了所有的*.py和*.wsgi文件-rwxr-xr-x
我使用 sudo a2ensite dash.conf 启用了站点配置并使用 udo systemctl reload apache2 重新加载了配置。
我相信 python 的版本运行是 python2.7（基于 apache error.log）；不确定如何指定 2.7 或 3。
如果我将 dashGAF.wsgi 编辑为 from dashGAF import server as application，我会收到 500 内部错误，但在服务器日志中有以下详细信息：

[Sun Jun 21 06:33:28.181450 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221] mod_wsgi (pid=12237): Target WSGI script '/var/www/html/wsgi/dashGAF.wsgi' cannot be loaded as Python module.
[Sun Jun 21 06:33:28.181512 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221] mod_wsgi (pid=12237): Exception occurred processing WSGI script '/var/www/html/wsgi/dashGAF.wsgi'.
[Sun Jun 21 06:33:28.181545 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221] Traceback (most recent call last):
[Sun Jun 21 06:33:28.181577 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221]   File "/var/www/html/wsgi/dashGAF.wsgi", line 4, in <module>
[Sun Jun 21 06:33:28.181685 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221]     from dashGAF import server as application
[Sun Jun 21 06:33:28.181714 2020] [wsgi:error] [pid 12237:tid 139670549669632] [client 118.210.193.245:52221] ImportError: cannot import name server

可能在“目标 WSGI 脚本‘/var/www/html/wsgi/dashGAF.wsgi’无法作为 Python 模块加载”这一点中有一个有用的细节。 ??

如果我将 dashGAF.wsgi 编辑为 application = app.server，我会得到一个 404 Not Foun：

from dashGAF import app
application = app.server

Answer 1

通常，您会在 wsgi 脚本中以 Flask 服务器而不是 Dash 应用程序为目标。也就是说，而不是

from dashGAF import app as application

应该是

from dashGAF import server as application

Answer 2

我对是否应该回答我自己的问题犹豫了一下。 @emher 的回答是问题的一部分 - 但不是整个解决方案。我需要解决一些问题，大部分故障排除都是由 @GrahamDumpleton 在 github 上指导的。如果他愿意，我很高兴他能提供答案。

尽管如此，以下是需要发生的问题和修复：

问题和修复：

按照@emher from dashGAF import server as application
没有必要包含 routes_pathname_prefix，它将仪表板解析为 https://ip.address/dashGAF/dashGAF`
/etc/apache2/sites-available/dash.conf 可以显着缩短`（见下文）
_dash-component-suites/dash_renderer/dash_renderer.dev.js 的请求失败，我不得不将 requests_pathname_prefix='/dashGAF/' 选项添加到我的 app = dash.Dash 行 (see link on github)

最终设置：

/etc/apache2/sites-available/dash.conf

WSGIDaemonProcess dashGAF user=ubuntu group=ubuntu home=/home/ubuntu threads=5
WSGIScriptAlias /dashGAF /var/www/html/wsgi/dashGAF.wsgi

WSGIProcessGroup dashGAF
WSGIApplicationGroup %{GLOBAL}

/var/www/html/wsgi/dashGAF.wsgi

#!/usr/bin/python
import sys
sys.path.insert(0,"/home/ubuntu/dashboards/")
from dashGAF import server as application

dashboards/dashGAF.py 同上，但包括：

app = dash.Dash(__name__, external_stylesheets=external_stylesheets, requests_pathname_prefix='/dashGAF/')
server = app.server

部署在 apache 服务器上的 Dash 失败 "Dash object not callable"

Dash deployed on apache server failing with "Dash object not callable"

python

apache

mod-wsgi

wsgi

plotly-dash