MAUSDjangoApache » History » Revision 4
Revision 3 (Jackson, Mike, 10 February 2012 13:49) → Revision 4/29 (Jackson, Mike, 10 February 2012 13:50)
h1. Deploying Django under Apache
{{>toc}}
h2. Apache 2.2 deployment
Apache 2.2 (http://httpd.apache.org/) is an HTTP server.
For full deployment information, see
* http://httpd.apache.org/docs/current/install.html
Following the "overview for the impatient"...
* Log in as root user,
<pre>
$ sudo su -
</pre>
* Download,
<pre>
$ lynx http://httpd.apache.org/download.cgi
</pre>
** Alternatively:
<pre>
$ wget http://mirrors.ukfast.co.uk/sites/ftp.apache.org//httpd/httpd-2.2.22.tar.gz
</pre>
* Extract,
<pre>
$ gzip -d httpd-2.2.22.tar.gz
$ tar xvf httpd-2.2.22.tar
$ cd httpd-2.2.22
</pre>
* Configure,
<pre>
$ ./configure
</pre>
** This uses a default deployment directory of @/usr/local/apache2@.
* Compile,
<pre>
$ make
</pre>
* Install,
<pre>
$ make install
</pre>
* Start-up server,
<pre>
$ /usr/local/apache2/bin/apachectl -k start
</pre>
** If you get an error like,
<pre>
(98)Address already in use: make_sock: could not bind to address [::]:80
(98)Address already in use: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs
</pre>
** Then edit @/usr/local/apache2/conf/httpd.conf@,
<pre>
$ xemacs /usr/local/apache2/conf/httpd.conf
</pre>
** and change,
<pre>
Listen 80
</pre>
** to a port that is not in use e.g.
<pre>
Listen 9090
</pre>
** and start Apache,
<pre>
$ /usr/local/apache2/bin/apachectl -k start
</pre>
* Browse to http://localhost:8080 (or whatever port you specified above) and you should see @It works!"@
Useful files:
* Configuration: @/usr/local/apache2/conf/httpd.conf@
* Error log: @/usr/local/apache2/logs/error_log@
h2. mod_wsgi deployment
mod_wsgi (http://code.google.com/p/modwsgi/) is an Apache module allowing the hosting of Python applications which suppport Python's WSGI (Web Server Gateway Interface).
For full deployment information, see
* http://code.google.com/p/modwsgi/wiki/InstallationInstructions
* http://code.google.com/p/modwsgi/wiki/InstallationIssues
Now, following the quick installation guide (http://code.google.com/p/modwsgi/wiki/QuickInstallationGuide),
* Download latest release (July 2010)
<pre>
$ wget http://modwsgi.googlecode.com/files/mod_wsgi-3.3.tar.gz
</pre>
* Extract,
<pre>
$ gunzip mod_wsgi-3.3.tar.gz
$ tar -xf mod_wsgi-3.3.tar
$ cd mod_wsgi-3.3
</pre>
* Set Python library path, if using a non-default Python distribution. The author uses MAUS Python, so set:
<pre>
$ export LD_LIBRARY_PATH=/home/michaelj/maus-bzr/maus/third_party/install/lib/
</pre>
* Configure,
<pre>
$ ./configure
</pre>
** If you get an error like:
<pre>
/home/michaelj/maus-bzr/maus/third_party/install/bin/python2.7: error while loading
shared libraries: libpython2.7.so.1.0: cannot open shared object file:
No such file or directory
</pre>
** Then set the @LD_LIBRARY_PATH@ as above.
** If using a non-default Python distribution, then add a @--with-python@ flag pointing to the Python executable. The author uses MAUS Python so set:
<pre>
--with-python=/home/michaelj/maus-bzr/maus/third_party/install/bin/python2.7
</pre>
** If you get an error like:
<pre>
checking for apxs2... no
checking for apxs... no
checking Apache version... ./configure: line 1704: apxs: command not found
./configure: line 1704: apxs: command not found
./configure: line 1705: apxs: command not found
./configure: line 1708: /: is a directory
checking for python... /home/michaelj/maus-bzr/maus/third_party/install/bin/python
./configure: line 1877: apxs: command not found
configure: creating ./config.status
config.status: error: cannot find input file: Makefile.in
</pre>
** Then explicitly provide the path to Apache's @apxs@ command,
<pre>
$ ./configure --with-apxs=/usr/local/apache2/bin/apxs
</pre>
** Combining the above gives,
<pre>
$ ./configure --with-apxs=/usr/local/apache2/bin/apxs
--with-python=/home/michaelj/maus-bzr/maus/third_party/install/bin/python2.7
</pre>
* Compile,
<pre>
$ make
</pre>
* Install,
<pre>
$ make install
</pre>
* A @mod_wsgi.so@ library is installed in @/usr/local/apache2/modules@.
* Configure Apache, edit @/usr/local/apache2/conf/httpd.conf@,
<pre>
$ xemacs /usr/local/apache2/conf/httpd.conf
</pre>
* and add,
<pre>
LoadModule wsgi_module modules/mod_wsgi.so
</pre>
* If you use a non-standard Python location and set @LD_LIBRARY_PATH@ above, then edit @/usr/local/apache2/bin/envvars@ and add a line to set the Python library path e.g.
<pre>
LD_LIBRARY_PATH="/home/michaelj/maus-bzr/maus/third_party/install/lib/:$LD_LIBRARY_PATH"
</pre>
* Restart Apache,
<pre>
$ /usr/local/apache2/bin/apachectl restart
</pre>
* If all is well you should see, in @/usr/local/apache2/logs/error_log@ a line like,
<pre>
[Tue Feb 07 18:50:37 2012] [notice] Apache/2.2.22 (Unix) mod_wsgi/3.3
Python/2.7.2 configured -- resuming normal operations
</pre>
* If you see an error like,
<pre>
[Tue Feb 07 18:46:40 2012] [notice] SIGHUP received. Attempting to restart
httpd: Syntax error on line 55 of /usr/local/apache2/conf/httpd.conf: Cannot
load /usr/local/apache2/modules/mod_wsgi.so into server:
libpython2.7.so.1.0: cannot open shared object file: No such file or directory
</pre>
** then you have to set the @LD_LIBRARY_PATH@ as above.
* Clean up,
<pre>
$ make clean
</pre>
To check your installation (following http://code.google.com/p/modwsgi/wiki/CheckingYourInstallation),
* List server information,
<pre>
$ /usr/local/apache2/bin/httpd -V
Server version: Apache/2.2.22 (Unix)
...
Server MPM: Prefork
threaded: no
forked: yes (variable process count)
Server compiled with....
-D APACHE_MPM_DIR="server/mpm/prefork"
...
</pre>
** Important information is the version and prefork settings,
* List compiled-in modules,
<pre>
$ /usr/local/apache2/bin/httpd -l
Compiled in modules:
...
prefork.c
</pre>
** You should see @prefork.c@.
* List dynamically-loaded modules,
<pre>
$ /usr/local/apache2/bin/httpd -M
mpm_prefork_module (static)
...
wsgi_module (shared)
...
</pre>
** You should see @wsgi_module@.
** If this fails with,
<pre>
httpd: Syntax error on line 55 of /usr/local/apache2/conf/httpd.conf:
Cannot load /usr/local/apache2/modules/mod_wsgi.so into server:
libpython2.7.so.1.0: cannot open shared object file: No such file or directory
</pre>
** Then set your @LD_LIBRARY_PATH@ as above and try again,
<pre>
$ export LD_LIBRARY_PATH="/home/michaelj/maus-bzr/maus/third_party/install/lib/:$LD_LIBRARY_PATH"
$ /usr/local/apache2/bin/httpd -M
Loaded Modules:
...
</pre>
* List modules linked to by @mod_wsgi@:
<pre>
$ ldd /usr/local/apache2/modules/mod_wsgi.so
...
libpython2.7.so.1.0 => /home/michaelj/maus-bzr/maus/third_party/install/lib/libpython2.7.so.1.0
(0x00110000)
...
</pre>
** You should see the link to your Python library.
h2. Deploying ImageMagick
The ImageMagick library is used to convert between image types in the MAUS web-front end.
To install,
* Log in as root user,
<pre>
$ sudo su -
</pre>
* Get and unpack ImageMagick,
<pre>
$ wget http://www.imagemagick.org/download/ImageMagick.tar.gz
$ gunzip ImageMagick.tar.gz
$ tar -xf ImageMagick.tar
$ cd ImageMagick-6.7.4-0/
</pre>
* Configure,
<pre>
$ ./configure
</pre>
* Make,
<pre>
$ make
</pre>
* Install,
<pre>
$ make install
</pre>
** This places libraries in @/usr/local/lib@.
* Cache the libraries,
<pre>
$ ldconfig /usr/local/lib
</pre>
** This avoids problems with libraries not being found by Python's magickwand library.
* Check,
<pre>
$ /usr/local/bin/convert -h
Version: ImageMagick 6.7.4-0 2011-12-13 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2011 ImageMagick Studio LLC
Features: OpenMP
</pre>
To install Python magickwand
* Setup the MAUS environment:
<pre>
$ source env.sh
</pre>
* Install,
<pre>
$ easy_install magickwand
</pre>
Check,
<pre>
$ python
$ import magickwand
$ from magickwand.image import Image
...
</pre>
* If you get an error like,
<pre>
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "build/bdist.linux-i686/egg/magickwand/image.py", line 2, in <module>
File "build/bdist.linux-i686/egg/magickwand/api/__init__.py", line 1, in <module>
#
File "build/bdist.linux-i686/egg/magickwand/api/lib.py", line 11, in <module>
File "/home/michaelj/maus-bzr/maus/third_party/install/lib/python2.7/ctypes/__init__.py",
line 353, in __init__ self._handle = _dlopen(self._name, mode)
OSError: libMagickWand.so.5: cannot open shared object file:
No such file or directory
</pre>
* then run @ldconfig@ as described above.
h2. Deploying the MAUS Django web front-end
For more on Django deployment under Apache 2.2/mod_wsgi, see
* https://docs.djangoproject.com/en/1.3/howto/deployment/modwsgi/
* http://code.google.com/p/modwsgi/wiki/IntegrationWithDjango
* Check-out the MAUS Django code,
<pre>
$ bzr branch -v http://code.launchpad.net/maus-apps/ maus-apps
</pre>
* Set-up environment,
<pre>
$ source env.sh
$ ./install.sh
</pre> ./install
* Change permissions on the @maus-apps/media@ directory, so the @apache@ user that Apache 2.2 runs under can update images,
<pre>
$ chmod -R go+rwx /home/michaelj/maus-apps/media/
</pre>
* Copy a couple of sample images,
<pre>
$ cp /home/michaelj/maus-apps/images/* /home/michaelj/maus-apps/media/raw
</pre>
* Log in as root user,
<pre>
$ sudo su -
</pre>
* Edit Apache 2.2 configuration,
<pre>
$ xemacs -nw /usr/local/apache2/conf/httpd.conf
</pre>
Add,
<pre>
WSGIScriptAlias / /home/michaelj/maus-apps/apache/django.wsgi
# Location of django.wsgi
<Directory /home/michaelj/maus-apps/apache>
Order deny,allow
Allow from all
</Directory>
</pre>
* where:
** @/@ specifies the root URL - so all URL requests will be directed to Django.
** @/...@ - location of WSGI file within the MAUS Django project.
* Change @/home/michaelj@ in the above to the location of your @maus-apps@ check-out.
* Edit Django WSGI configuration file @/home/michaelj/maus-apps/apache/django.wsgi@
** Change @/home/michaelj@ in the above to the location of your @maus-apps@ check-out.
* Edit Apache 2.2 environment, so it has access to the MAUS environment (in particular all the Python libraries that have been easy_installed):
<pre>
$ xemacs -nw /usr/local/apache2/bin/envvars
</pre>
* Add
<pre>
source /home/michaelj/maus-bzr/maus/env.sh
</pre>
<pre>
$ xemacs -nw /usr/local/apache2/bin/envvars
</pre>
* Restart Apache 2.2,
<pre>
$ /usr/local/apache2/bin/apachectl restart
</pre>
* Test,
** Visit http://localhost:8080/maus/, remembering to change the port number if you use a custom port.