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POWhy is sys.path initialized differently during startup than when run from bash, for Python embedded in Apache
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copied!<p>I am using Python embedded in Apache using modwsgi, and I am finding that the sys.path does not get initialized correctly when Apache is started from the rc2.d startup folder than when run from the shell. </p> <p>The versions:<br> Ubuntu Lucid 10.04<br> Apache 2.2<br> Python 2.6<br> mod_wsgi 3.3</p> <p>Firstly, I am testing the initialization using this app:</p> <pre><code>import sys import os def application(environ, start_response): status = '200 OK' output = ['version %s\n'%sys.version] output.append('sys.prefix = %s \n' % repr(sys.prefix)) output.append('sys.exec_prefix = %s \n' % repr(sys.exec_prefix)) output.append('sys.path = %s \n' % repr(sys.path)) output.append('env.PYTHONHOME = %s\n' % repr(os.environ.get('PYTHONHOME'))) output.append('env.PATH = %s\n' % repr(os.environ.get('PATH'))) response_headers = [('Content-type', 'text/plain'), ('Content-Length', str(sum([len(o) for o in output])))] start_response(status, response_headers) return output </code></pre> <p>When apache2 is started from bash, via 'sudo apache2ctl start', or 'sudo /etc/init.d/apache2 start', it initializes correctly, and the app above shows:</p> <pre><code>version 2.6.5 (r265:79063, Apr 16 2010, 14:15:55) [GCC 4.4.3] sys.prefix = '/usr' sys.exec_prefix = '/usr/local' sys.path = ['/usr/local/lib/python2.6/dist-packages/WebOb-1.0.7-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/twiddler-0.9.1-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/elementtree-1.2.7_20070827_preview-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/lxml-2.3-py2.6-linux-x86_64.egg', '/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2', '/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old', '/usr/local/lib/python2.6/lib-dynload', '/usr/lib/python2.6/dist-packages', '/usr/lib/pymodules/python2.6', '/usr/local/lib/python2.6/dist-packages', '/usr/local/lib/python2.6/dist-packages'] env.PYTHONHOME = '/usr:/usr/local' env.PATH = '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin' </code></pre> <p>When apache2 is started from /etc/rc2.d during boot, it does not initialize correctly, and the app shows:</p> <pre><code>version 2.6.5 (r265:79063, Apr 16 2010, 14:15:55) [GCC 4.4.3] sys.prefix = '/usr' sys.exec_prefix = '/usr/local' sys.path = ['/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2', '/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old', '/usr/local/lib/python2.6/lib-dynload'] env.PYTHONHOME = '/usr:/usr/local' env.PATH = '/sbin:/usr/sbin:/bin:/usr/bin' </code></pre> <p>Critical directories are not found, including dist-packages. </p> <p>I have tried moving the apache script earlier and later in the startup sequence, and gotten uniformly bad results. Loading apache last in the startup gets the dysfunctional sys.path; loading it from the shell, immediately afterward, loads correctly.</p> <p>The question, again, is why would the sys.path initialize differently run as a startup process than run from the shell?</p> <p>Follow-up:</p> <p>site.py is not being run by Python's initialization. Now I am seeing mod_wsgi errors "unable to import 'site' module". The errors started appearing after providing a WSGIPythonPath value in Apach2.conf, though the sys.path symptoms have been there all along.</p> <p>There is something about the combination of chrooting Apache and starting from rc#.d scripts that is breaking Python's site.py loading.</p> <p>Launching Apache from the shell, via sudo, or sudo -i, from a brand new account, works fine.</p>

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