cherrypy / dev / urandom（或等效）未找到 - 错误

Question

我正在使用Python 2.5.1运行一个cherrypy 3.2.0服务器，它会在UI的任何指令中每隔几天发出以下错误，直到它被杀死并重新启动： -

[29/Mar/2012:06:37:57] HTTP Traceback (most recent call last):
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 636, in respond
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 97, in run
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 57, in __call__
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/lib/sessions.py", line 757, in init
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/lib/sessions.py", line 162, in __init__
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/lib/sessions.py", line 190, in _regenerate
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/lib/sessions.py", line 204, in generate_id
File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cpcompat.py", line 264, in random20
File "/usr/lib/python2.5/os.py", line 733, in urandom
NotImplementedError: /dev/urandom (or equivalent) not found

_cpcompat.py有以下代码段，表示如果cherrypy无法读取random.random，/dev/urandom会有回退，但似乎没有回落它

try:
    os.urandom(20)
    import binascii
    def random20():
        return binascii.hexlify(os.urandom(20)).decode('ascii')

except (AttributeError, NotImplementedError):
    import random
    # os.urandom not available until Python 2.4. Fall back to random.random.
    def random20(): 
        return sha('%s' % random.random()).hexdigest()

try: os.urandom(20) import binascii def random20(): return binascii.hexlify(os.urandom(20)).decode('ascii') except (AttributeError, NotImplementedError): import random # os.urandom not available until Python 2.4. Fall back to random.random. def random20(): return sha('%s' % random.random()).hexdigest()

以下是来自的代码段，与上下文相关： -

os.py

if not _exists("urandom"):

    def urandom(n):
        """urandom(n) -> str

        Return a string of n random bytes suitable for cryptographic use.

        """
        try:
            _urandomfd = open("/dev/urandom", O_RDONLY)
        except (OSError, IOError):
            raise NotImplementedError("/dev/urandom (or equivalent) not found")
        bytes = ""
        while len(bytes) < n:
            bytes += read(_urandomfd, n - len(bytes))
        close(_urandomfd)
        return bytes

在cherrypy无法阅读 def urandom(n): """urandom(n) -> str Return a string of n random bytes suitable for cryptographic use. """ try: _urandomfd = open("/dev/urandom", O_RDONLY) except (OSError, IOError): raise NotImplementedError("/dev/urandom (or equivalent) not found") bytes = "" while len(bytes) < n: bytes += read(_urandomfd, n - len(bytes)) close(_urandomfd) return bytes 的同时，以下代码段工作正常： -

我有两个问题： -

1. 当我能够从/ dev / urandom读取随机位时，为什么cherrypy throw没有实现错误
2. 为/dev/urandom提出 python -c "import os;fd = open('/dev/urandom', 'r');print fd.read(5);fd.close()" 时，为什么_cpcompact.py没有执行除外部分。

Answer 1

这也不是一个答案，但是，根据我的经验，这个NotImplementedError是错误的，但是当“太多文件”打开错误时会出现错误，在多处理过程开始时会出现错误进程开始抛出未捕获的异常，留下来永远隐藏在子线程中或儿童过程。

我会开始进一步调试堆栈，看看是否有进程抛出的隐藏或无提示异常

这是我开始看到此错误时的堆栈跟踪示例

Exception in thread Plotter:
Traceback (most recent call last):
  File "threading.pyc", line 532, in __bootstrap_inner
  File "plotters/edge.pyc", line 459, in run
  AttributeError: 'error' object has no attribute 'error'

OSError: [Errno 24] Too many open files
  File "multiprocessing/connection.pyc", line 150, in Client
  File "multiprocessing/connection.pyc", line 370, in deliver_challenge
    None
  File "os.pyc", line 756, in urandom
NotImplementedError: /dev/urandom (or equivalent) not found

我的AttributeError产生，最终...... / urandom未找到imlp错误

Answer 2

这不是一个答案，但也许您可以将一些调试代码放入os.py（我无法想象它会影响使用import os的任何其他程序，但它值得记住它的自定义）< / p>

if not _exists("urandom"):
    def urandom(n):
        """urandom(n) -> str

        Return a string of n random bytes suitable for cryptographic use.

        """
        try:
            _urandomfd = open("/dev/urandom", O_RDONLY)
        # debug changes
        except (OSError, IOError) as Err:
            import syslog
            syslog.syslog(repr(Err))
        # /debug
            raise NotImplementedError("/dev/urandom (or equivalent) not found")
        bytes = ""
        while len(bytes) < n:
            bytes += read(_urandomfd, n - len(bytes))
        close(_urandomfd)
        return bytes

希望这能告诉你错误是什么。 （当然，您只需要写入文件等替换syslog）

Answer 3

如果您的系统没有创建/ dev / random和/ dev / urandom，可以使用以下命令创建它们：

mknod -m 644 / dev / random c 1 8

mknod -m 644 / dev / urandom c 1 9

chown root：root / dev / random / dev / urandom