Python（Twisted + ZSI）中的Web服务调用在chroot监狱中不起作用

Question

I have a Python script that calls a web service using ZSI with Twisted. On Linux, I'm running this script and it works fine.

Now, I want this script to run in a chroot jail which is somewhere in my filesystem. I have added the usr, lib and the etc directories in the jail. When I execute the script from the jail, there is no response from the web service and Twisted reports an error which looks like:

[Failure instance: Traceback (failure with no frames): twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion. ]

If I chroot to the root of the filesystem (/) and if the new jail uses the already existing usr, lib and etc directories, it works with no errors.

I'm suspecting that there is a library that's missing or a library in the bin/usr/etc directories of the first chroot jail that is not correct. Do you have any clue that can help me? Does somebody have a solution to this problem?

Answer 1

If your application is raising an unexpected exception at some point - eg, because some dependency fails to import, because it is not installed in the chroot - then this can cause connections to be unexpectedly closed. It's hard to say with any precision, since you haven't mentioned what kind of connections you have or what APIs you're using to manage them.

Make sure you have logging enabled and look for unexpected tracebacks being written to your log file. If you see any, there's a good chance they are associated with the problem that is causing your application to fail.