Apache & mod_fastcgi Deployment

The Apache/mod_fastcgi setup is intended as an easy way for users with shared hosting environments to use python webapps. It adds some overhead over the Apache & mod_wsgi Deployment, so if you administrate your own server, you may want to use that instead.

This tutorial assumes that you already have Apache and mod_fastcgi installed and working. If you’re unsure, check with your hosting provider.

Components

The following six components are involved in getting web requests through to mediacore with this setup. Don’t worry if this sounds like a lot! By this stage you already have three, and the remaining ones are very easy to set up.

Apache

the web server

mod_fastcgi

Apache module that lets Apache run FastCGI scripts

.htaccess

tells Apache which requests to send to our FastCGI script

mediacore.fcgi

the FastCGI script, uses flup to run mediacore

flup

provides a WSGI interface for mediacore to get data from Apache

mediacore

the reason we’re here!

Instructions

NOTE 1: The following instructions assume that you’re deploying MediaCore to http://yourdomain.com/my_media/. To deploy mediacore to any other directory of your website, the process is very simple: Instead of putting the files into /path/to/document_root/my_media, like in the instructions below, put them into the folder you want to serve from, and change the prefix config line to match.

NOTE 2: If deploying mediacore inide an existing directory, you must make sure that the mediacore .htaccess file doesn’t overwrite any existing .htaccess file in that directory–you’ll have to copy the contents over to the existing .htaccess file if there is one, and make sure that the contents of the two files make sense together.

First, install the flup Python package:

# If your virtual environment is not activated, activate it:
source /path/to/mediacore_env/bin/activate

# Install flup:
easy_install flup

Second, create a temporary directory and a python cache directory for your deployment to use.

cd /path/to/mediacore_install/data
mkdir tmp
mkdir python-egg-cache

Permissions: Now is a good time to make sure that all of the apropriate files have the correct permissions. The following files/directories should be writeable by your apache user. (Depending on how your server is set up, the user name may be different).

1. all of the folders inside the /path/to/mediacore_install/data/
2. /path/to/mediacore_install/mediacore/public/images/podcasts/
3. /path/to/mediacore_install/mediacore/public/images/media/

Third, create a directory named my_media inside your website’s document root. Copy all the files from /path/to/mediacore_install/deployment-scripts/mod_fastcgi into the new my_media directory (this includes .htaccess, mediacore.fcgi, and mediacore-restart.sh).

# Create the my_media directory:
cd /path/to/document_root
mkdir my_media

# Copy the deployment files
cp /path/to/mediacore/install/deployment-scripts/mod_fastcgi/* ./my_media/
cp /path/to/mediacore/install/deployment-scripts/mod_fastcgi/.htaccess ./my_media/

Permissions: Make sure that the ./my_media/fastcgi.pid file is writeable by your apache user.

Fourth, create a symbolic link (symlink) to the public directory from your mediacore installation:

# Create a symlink to the public directory
ln -sf /path/to/mediacore/install/mediacore/public ./my_media/public

Fifth, you’ll need to edit the paths in my_media/mediacore.fcgi to point to your own mediacore installation and virtual environment. The four (4) lines you need to edit are at the top of the file, and look like this:

#!/path/to/mediacore_env/bin/python
python_egg_cache = '/path/to/mediacore_install/data/python-egg-cache'
deployment_config = '/path/to/mediacore_install/deployment.ini'
temp_dir = '/path/to/mediacore_install/data/tmp'

Finally, edit one line in /path/to/mediacore_install/deployment.ini. Find the proxy_prefix line, uncomment it, and set the prefix to /my_media. This will ensure that the URLs generated within the application point to the right place:

proxy_prefix = /my_media

Testing Installation

Our first step after deployment is to test the app. To get FastCGI to run MediaCore for the first time, point your browser to http://yourdomain/my_media

If you don’t see MediaCore make sure you’ve followed all of the instructions above!

Performance Enhancements

By default, all files are served through MediaCore. The configuration above ensures that Apache will serve all static files (.css, .js, and images) directly, but MediaCore will still check for static files before serving any page. There are two speedups we can enable here.

First, edit one line in /path/to/mediacore_install/deployment.ini. Find the static_files line, and set it to false.

static_files = false

The second speedup is only available if you have mod_xsendfile installed and enabled in Apache. MediaCore can take advantage of mod_xsendfile and have Apache serve all media files (.mp3, .mp4, etc.) directly. To enable this, edit another line in /path/to/mediacore_install/deployment.ini. Find the files_serve_method line, and set it to apache_xsendfile.

files_serve_method = apache_xsendfile

Editing MediaCore

If you make any changes to your MediaCore installation while Apache is running (eg. if you upgrade MediaCore or make any customizations), you’ll need to make sure that mod_fastcgi recognizes those changes.

The easiest way to do this is to ‘touch’ the .fcgi script. This will modify the ‘last modified on’ timestamp of the file, so that mod_fastcgi thinks it has been updated and will read and re-load it.

# Navigate to the my_media directory:
cd /path/to/document_root
cd my_media

# Force a refresh of the mediacore code
touch mediacore.fcgi