Flask 在 Linux 服务器上找不到 Pandoc (nginx+uwsgi)
Flask cannot find Pandoc on Linux Server (nginx+uwsgi)
您好，我刚刚按照本教程在 Digital Ocean 上的远程 ubuntu 服务器上部署了我的 Flask 应用程序：https://www.digitalocean.com/community/tutorials/how-to-serve-flask-applications-with-uswgi-and-nginx-on-ubuntu-18-04
一切正常，只是当我导入 pyPandoc 时找不到 pandoc。我导入 pypandoc 的代码是这样的：
import pypandoc
try:
from pypandoc.pandoc_download import download_pandoc
except:
pass
这在我的本地运行良好，但在服务器上出现错误：
[2020-04-09 16:16:37,027] ERROR in app: Exception on /get_all_articles [POST]
Traceback (most recent call last):
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "./main.py", line 285, in get_all_articles
return jsonify(myFirebase.get_all_articles(pending))
File "services/myFirebase.py", line 343, in get_all_articles
text = pypandoc.convert_text(text,'html',format='md')
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 103, in convert_text
outputfile=outputfile, filters=filters)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 260, in _convert_input
_ensure_pandoc_path()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 544, in _ensure_pandoc_path
raise OSError("No pandoc was found: either install pandoc and add it\n"
OSError: No pandoc was found: either install pandoc and add it
to your PATH or or call pypandoc.download_pandoc(...) or
install pypandoc wheels with included pandoc.
我尝试通过 pip、apt 安装 Pandoc，甚至按照官方 Pandoc 文档的建议下载 Debian 文件。似乎没有任何效果。在 pyPandoc 网站上：https://pypi.org/project/pypandoc/
它说了一些关于使用 wheel 安装 Pandoc 的内容，但我不确定我是否理解它的含义并且我不熟悉该过程。你知道如何让 pyPandoc 在我部署的 Flask 应用程序上运行吗？
附加信息：
我的 Flask 应用程序 运行 在虚拟环境中，如上面链接的教程所述。我试图从虚拟环境中访问 Pandoc，这是我的输出：
fmagarelli@InfantTestServer:~/Infant_Competition_Platform$ source venv3/bin/activate
(venv3) fmagarelli@InfantTestServer:~/Infant_Competition_Platform$ pandoc --version
pandoc 2.9.2.1
Compiled with pandoc-types 1.20, texmath 0.12.0.1, skylighting 0.8.3.2
Default user data directory: /home/fmagarelli/.local/share/pandoc or /home/fmagarelli/.pandoc
Copyright (C) 2006-2020 John MacFarlane
Web: https://pandoc.org
This is free software; see the source for copying conditions.
There is no warranty, not even for merchantability or fitness
for a particular purpose.
EDIT2 添加 PDB：
所以将我的导入更改为：
from pypandoc.pandoc_download import download_pandoc
import pypandoc
import pdb; pdb.set_trace()
现在这是我的输出：
[2020-04-09 17:31:46,358] ERROR in app: Exception on /get_all_articles [POST]
Traceback (most recent call last):
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/_compat.py", line 39, in reraise
raise value
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "./main.py", line 285, in get_all_articles
return jsonify(myFirebase.get_all_articles(pending))
File "services/myFirebase.py", line 344, in get_all_articles
art['title'] = line.replace('#','')
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/pypandoc/__init__.py", line 103, in convert_text
outputfile=outputfile, filters=filters)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/pypandoc/__init__.py", line 260, in _convert_input
_ensure_pandoc_path()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 544, in _ensure_pandoc_path
raise OSError("No pandoc was found: either install pandoc and add it\n"
OSError: No pandoc was found: either install pandoc and add it
to your PATH or or call pypandoc.download_pandoc(...) or
install pypandoc wheels with included pandoc.
[pid: 1159|app: 0|req: 2/8] 46.7.82.176 () {48 vars in 893 bytes} [Thu Apr 9 17:31:46 2020] POST /get_all_articles => generated 290 bytes in 325 msecs (HTTP/1.1 500) 2 headers in 99 bytes (1 switches on core 0)
SIGINT/SIGQUIT received...killing workers...
worker 1 buried after 1 seconds
worker 2 buried after 1 seconds
worker 3 buried after 1 seconds
worker 4 buried after 1 seconds
worker 5 buried after 1 seconds
goodbye to uWSGI.
VACUUM: unix socket main.sock removed.
*** Starting uWSGI 2.0.18 (64bit) on [Thu Apr 9 17:41:27 2020] ***
compiled with version: 7.5.0 on 09 April 2020 15:04:16
os: Linux-4.15.0-66-generic #75-Ubuntu SMP Tue Oct 1 05:24:09 UTC 2019
nodename: InfantTestServer
machine: x86_64
clock source: unix
detected number of CPU cores: 1
current working directory: /home/fmagarelli/Infant_Competition_Platform
detected binary path: /home/fmagarelli/Infant_Competition_Platform/venv3/bin/uwsgi
!!! no internal routing support, rebuild with pcre support !!!
your processes number limit is 3842
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
thunder lock: disabled (you can enable it with --thunder-lock)
uwsgi socket 0 bound to UNIX address main.sock fd 3
Python version: 3.6.9 (default, Nov 7 2019, 10:44:02) [GCC 8.3.0]
*** Python threads support is disabled. You can enable it with --enable-threads ***
Python main interpreter initialized at 0x55c9e3a74470
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 437520 bytes (427 KB) for 5 cores
*** Operational MODE: preforking ***
> /home/fmagarelli/Infant_Competition_Platform/services/myFirebase.py(13)<module>()
-> import random
(Pdb)
Traceback (most recent call last):
File "./wsgi.py", line 1, in <module>
from main import app
File "./main.py", line 21, in <module>
import myFirebase
File "services/myFirebase.py", line 13, in <module>
import random
File "services/myFirebase.py", line 13, in <module>
import random
File "/usr/lib/python3.6/bdb.py", line 51, in trace_dispatch
return self.dispatch_line(frame)
File "/usr/lib/python3.6/bdb.py", line 70, in dispatch_line
if self.quitting: raise BdbQuit
bdb.BdbQuit
unable to load app 0 (mountpoint='') (callable not found or import error)
*** no app loaded. going in full dynamic mode ***
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI master process (pid: 893)
spawned uWSGI worker 1 (pid: 1040, cores: 1)
spawned uWSGI worker 2 (pid: 1041, cores: 1)
spawned uWSGI worker 3 (pid: 1042, cores: 1)
spawned uWSGI worker 4 (pid: 1043, cores: 1)
spawned uWSGI worker 5 (pid: 1044, cores: 1)
--- no python application found, check your startup logs for errors ---
[pid: 1040|app: -1|req: -1/1] 46.7.82.176 () {42 vars in 793 bytes} [Thu Apr 9 17:41:34 2020] GET /main.html => generated 21 bytes in 0 msecs (HTTP/1.1 500) 2 headers in 83 bytes (1 switches on core 0)
我解决了，显然这是一个很常见的问题，他们在 pypandoc 存储库中提出了拉取请求：
https://github.com/bebraw/pypandoc/issues/72#issuecomment-219283647
https://github.com/bebraw/pypandoc/pull/99/commits/5be3973b2a2c7eeb1abd6521c13374d82aa5ba99
所以激活虚拟环境后，运行which pandoc获取Pandoc的路径：
#activate env:
source myenv/bin/activate
which pandoc
OUT: '/usr/bin/pandoc'
然后将其添加到烧瓶应用程序中：
os.environ.setdefault('PYPANDOC_PANDOC','/usr/bin/pandoc')
您好，我刚刚按照本教程在 Digital Ocean 上的远程 ubuntu 服务器上部署了我的 Flask 应用程序：https://www.digitalocean.com/community/tutorials/how-to-serve-flask-applications-with-uswgi-and-nginx-on-ubuntu-18-04
一切正常，只是当我导入 pyPandoc 时找不到 pandoc。我导入 pypandoc 的代码是这样的：
import pypandoc
try:
from pypandoc.pandoc_download import download_pandoc
except:
pass
这在我的本地运行良好，但在服务器上出现错误：
[2020-04-09 16:16:37,027] ERROR in app: Exception on /get_all_articles [POST]
Traceback (most recent call last):
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "./main.py", line 285, in get_all_articles
return jsonify(myFirebase.get_all_articles(pending))
File "services/myFirebase.py", line 343, in get_all_articles
text = pypandoc.convert_text(text,'html',format='md')
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 103, in convert_text
outputfile=outputfile, filters=filters)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 260, in _convert_input
_ensure_pandoc_path()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 544, in _ensure_pandoc_path
raise OSError("No pandoc was found: either install pandoc and add it\n"
OSError: No pandoc was found: either install pandoc and add it
to your PATH or or call pypandoc.download_pandoc(...) or
install pypandoc wheels with included pandoc.
我尝试通过 pip、apt 安装 Pandoc，甚至按照官方 Pandoc 文档的建议下载 Debian 文件。似乎没有任何效果。在 pyPandoc 网站上：https://pypi.org/project/pypandoc/
它说了一些关于使用 wheel 安装 Pandoc 的内容，但我不确定我是否理解它的含义并且我不熟悉该过程。你知道如何让 pyPandoc 在我部署的 Flask 应用程序上运行吗？
附加信息：
我的 Flask 应用程序 运行 在虚拟环境中，如上面链接的教程所述。我试图从虚拟环境中访问 Pandoc，这是我的输出：
fmagarelli@InfantTestServer:~/Infant_Competition_Platform$ source venv3/bin/activate
(venv3) fmagarelli@InfantTestServer:~/Infant_Competition_Platform$ pandoc --version
pandoc 2.9.2.1
Compiled with pandoc-types 1.20, texmath 0.12.0.1, skylighting 0.8.3.2
Default user data directory: /home/fmagarelli/.local/share/pandoc or /home/fmagarelli/.pandoc
Copyright (C) 2006-2020 John MacFarlane
Web: https://pandoc.org
This is free software; see the source for copying conditions.
There is no warranty, not even for merchantability or fitness
for a particular purpose.
EDIT2 添加 PDB：
所以将我的导入更改为：
from pypandoc.pandoc_download import download_pandoc
import pypandoc
import pdb; pdb.set_trace()
现在这是我的输出：
[2020-04-09 17:31:46,358] ERROR in app: Exception on /get_all_articles [POST]
Traceback (most recent call last):
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/_compat.py", line 39, in reraise
raise value
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "./main.py", line 285, in get_all_articles
return jsonify(myFirebase.get_all_articles(pending))
File "services/myFirebase.py", line 344, in get_all_articles
art['title'] = line.replace('#','')
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/pypandoc/__init__.py", line 103, in convert_text
outputfile=outputfile, filters=filters)
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-package
s/pypandoc/__init__.py", line 260, in _convert_input
_ensure_pandoc_path()
File "/home/fmagarelli/Infant_Competition_Platform/venv3/lib/python3.6/site-packages/pypandoc/__init__.py", line 544, in _ensure_pandoc_path
raise OSError("No pandoc was found: either install pandoc and add it\n"
OSError: No pandoc was found: either install pandoc and add it
to your PATH or or call pypandoc.download_pandoc(...) or
install pypandoc wheels with included pandoc.
[pid: 1159|app: 0|req: 2/8] 46.7.82.176 () {48 vars in 893 bytes} [Thu Apr 9 17:31:46 2020] POST /get_all_articles => generated 290 bytes in 325 msecs (HTTP/1.1 500) 2 headers in 99 bytes (1 switches on core 0)
SIGINT/SIGQUIT received...killing workers...
worker 1 buried after 1 seconds
worker 2 buried after 1 seconds
worker 3 buried after 1 seconds
worker 4 buried after 1 seconds
worker 5 buried after 1 seconds
goodbye to uWSGI.
VACUUM: unix socket main.sock removed.
*** Starting uWSGI 2.0.18 (64bit) on [Thu Apr 9 17:41:27 2020] ***
compiled with version: 7.5.0 on 09 April 2020 15:04:16
os: Linux-4.15.0-66-generic #75-Ubuntu SMP Tue Oct 1 05:24:09 UTC 2019
nodename: InfantTestServer
machine: x86_64
clock source: unix
detected number of CPU cores: 1
current working directory: /home/fmagarelli/Infant_Competition_Platform
detected binary path: /home/fmagarelli/Infant_Competition_Platform/venv3/bin/uwsgi
!!! no internal routing support, rebuild with pcre support !!!
your processes number limit is 3842
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
thunder lock: disabled (you can enable it with --thunder-lock)
uwsgi socket 0 bound to UNIX address main.sock fd 3
Python version: 3.6.9 (default, Nov 7 2019, 10:44:02) [GCC 8.3.0]
*** Python threads support is disabled. You can enable it with --enable-threads ***
Python main interpreter initialized at 0x55c9e3a74470
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 437520 bytes (427 KB) for 5 cores
*** Operational MODE: preforking ***
> /home/fmagarelli/Infant_Competition_Platform/services/myFirebase.py(13)<module>()
-> import random
(Pdb)
Traceback (most recent call last):
File "./wsgi.py", line 1, in <module>
from main import app
File "./main.py", line 21, in <module>
import myFirebase
File "services/myFirebase.py", line 13, in <module>
import random
File "services/myFirebase.py", line 13, in <module>
import random
File "/usr/lib/python3.6/bdb.py", line 51, in trace_dispatch
return self.dispatch_line(frame)
File "/usr/lib/python3.6/bdb.py", line 70, in dispatch_line
if self.quitting: raise BdbQuit
bdb.BdbQuit
unable to load app 0 (mountpoint='') (callable not found or import error)
*** no app loaded. going in full dynamic mode ***
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI master process (pid: 893)
spawned uWSGI worker 1 (pid: 1040, cores: 1)
spawned uWSGI worker 2 (pid: 1041, cores: 1)
spawned uWSGI worker 3 (pid: 1042, cores: 1)
spawned uWSGI worker 4 (pid: 1043, cores: 1)
spawned uWSGI worker 5 (pid: 1044, cores: 1)
--- no python application found, check your startup logs for errors ---
[pid: 1040|app: -1|req: -1/1] 46.7.82.176 () {42 vars in 793 bytes} [Thu Apr 9 17:41:34 2020] GET /main.html => generated 21 bytes in 0 msecs (HTTP/1.1 500) 2 headers in 83 bytes (1 switches on core 0)
我解决了，显然这是一个很常见的问题，他们在 pypandoc 存储库中提出了拉取请求：
https://github.com/bebraw/pypandoc/issues/72#issuecomment-219283647
https://github.com/bebraw/pypandoc/pull/99/commits/5be3973b2a2c7eeb1abd6521c13374d82aa5ba99
所以激活虚拟环境后，运行which pandoc获取Pandoc的路径：
#activate env:
source myenv/bin/activate
which pandoc
OUT: '/usr/bin/pandoc'
然后将其添加到烧瓶应用程序中：
os.environ.setdefault('PYPANDOC_PANDOC','/usr/bin/pandoc')