How to debug python application under uWSGI?

问题:

When I'm trying to use python pdb debugger under uWSGI, the execution doesn't stop on breakpoint, it just return trackback.

here is the code:

def application(env, start_response):
    import pdb; pdb.set_trace()
    start_response('200 OK', [('Content-Type','text/html')])
    return "Hello World"

this is how I run it:

uwsgi --http 127.0.0.1:7777  --wsgi-file uwsgi_test.py

and this is what I get:

/home/andrey/Development/ttt/uwsgi_test.py(3)application()
-> start_response('200 OK', [('Content-Type','text/html')])
(Pdb) 
Traceback (most recent call last):
  File "uwsgi_test.py", line 3, in application
    start_response('200 OK', [('Content-Type','text/html')])
  File "uwsgi_test.py", line 3, in application
    start_response('200 OK', [('Content-Type','text/html')])
  File "/usr/lib/python2.7/bdb.py", line 48, in trace_dispatch
    return self.dispatch_line(frame)
  File "/usr/lib/python2.7/bdb.py", line 67, in dispatch_line
    if self.quitting: raise BdbQuit
bdb.BdbQuit
[pid: 11421|app: 0|req: 1/1] 127.0.0.1 () {32 vars in 366 bytes} [Sun Aug 25 13:12:06 2013] GET / => generated 0 bytes in 63 msecs (HTTP/1.1 500) 0 headers in 0 bytes (0 switches on core 0)

回答1:

Being a server, uWSGI closes the stdin (effectively it remaps it to /dev/null).

If you need stdin (as when you need a terminal debugger) add:

--honour-stdin

回答2:

Install remote debugger.

pip install remote-pdb

Set breakpoint somewhere in application.

from remote_pdb import RemotePdb
RemotePdb('127.0.0.1', 4444).set_trace()

Connect to remote debugger via telnet

# Restart uwsgi to pick up changes
...

# Trigger the breakpoint, (any action to evaluate the set_trace call)
...

# Connect to debugger
telnet 127.0.0.1 4444

You will likely want to run uWSGI with a single worker/thread, so that the remote debuggers do not step on one another.

回答3:

try this

uwsgi --http 127.0.0.1:7777  --wsgi-file uwsgi_test.py --logto /path/to/log/log.txt