I followed your wonderful script, but chown -R apache:apache /opt/graphite/storage/ was not enough getting errors below. I had to chown -R apache:apache /opt/graphite/ Thank you for your scripts!

[Wed Aug 28 15:10:36 2013] [error] [client 192.168.1.40] mod_wsgi (pid=1366): Target WSGI script '/opt/graphite/conf/graphite.wsgi' cannot be loaded as Python module.
[Wed Aug 28 15:10:36 2013] [error] [client 192.168.1.40] mod_wsgi (pid=1366): Exception occurred processing WSGI script '/opt/graphite/conf/graphite.wsgi'.

You don't actually need to disable selinux (or you would have already done it by default in your installation)
http://devinvenable.blogspot.com/2010/01/apache-modwsgi-django-selinux.html
chcon -R -t httpd_sys_content_t /opt/graphite/storage/

Git clones now need to be changed to https URLs. I received RPC errors otherwise.

This gave me Twisted 13.2 which is incompatible with carbon-cache. Had to downgrade to Twisted 12.

Error:

Traceback (most recent call last):
  File "./bin/carbon-cache.py", line 28, in <module>
    from carbon.util import run_twistd_plugin
  File "/opt/graphite/lib/carbon/util.py", line 21, in <module>
    from twisted.scripts._twistd_unix import daemonize
ImportError: cannot import name daemonize

Solution:

pip install 'Twisted<12.0'

Other solutions
http://stackoverflow.com/questions/19894708/cant-start-carbon-12-04-python-error-importerror-cannot-import-name-daem

Line 80 Should read

service httpd start

Lines 84 and 95 should use https. Trying to clone from an http url won't work.

https://github.com/joyent/node.git
https://github.com/etsy/statsd.git