Deploying MediaGoblin

GNU MediaGoblin is fairly new and so at the time of writing, there aren’t easy package-manager-friendly methods to install MediaGoblin. However, doing a basic install isn’t too complex in and of itself.

There’s an almost infinite way to deploy things... for now, we’ll keep it simple with some assumptions and use a setup that combines mediagoblin + virtualenv + fastcgi + nginx on a .deb or .rpm based GNU/Linux distro.

Note

These tools are for site administrators wanting to deploy a fresh install. If instead you want to join in as a contributor, see our Hacking HOWTO instead.

There are also many ways to install servers... for the sake of simplicity, our instructions below describe installing with nginx. For more recipes, including Apache, see our wiki.

Prepare System

Dependencies

MediaGoblin has the following core dependencies:

On a DEB-based system (e.g Debian, gNewSense, Trisquel, Ubuntu, and derivatives) issue the following command:

sudo apt-get install git-core python python-dev python-lxml \
    python-imaging python-virtualenv

On a RPM-based system (e.g. Fedora, RedHat, and derivatives) issue the following command:

yum install python-paste-deploy python-paste-script \
    git-core python python-devel python-lxml python-imaging \
    python-virtualenv

Configure PostgreSQL

Note

MediaGoblin currently supports PostgreSQL and SQLite. The default is a local SQLite database. This will “just work” for small deployments.

For medium to large deployments we recommend PostgreSQL.

If you don’t want/need postgres, skip this section.

These are the packages needed for Debian Wheezy (testing):

sudo apt-get install postgresql postgresql-client python-psycopg2

The installation process will create a new system user named postgres, it will have privilegies sufficient to manage the database. We will create a new database user with restricted privilegies and a new database owned by our restricted database user for our MediaGoblin instance.

In this example, the database user will be mediagoblin and the database name will be mediagoblin too.

To create our new user, run:

sudo -u postgres createuser mediagoblin

then answer NO to all the questions:

Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) n
Shall the new role be allowed to create more new roles? (y/n) n

then create the database all our MediaGoblin data should be stored in:

sudo -u postgres createdb -E UNICODE -O mediagoblin mediagoblin

where the first mediagoblin is the database owner and the second mediagoblin is the database name.

Caution

Where is the password?

These steps enable you to authenticate to the database in a password-less manner via local UNIX authentication provided you run the MediaGoblin application as a user with the same name as the user you created in PostgreSQL.

More on this in Drop Privileges for MediaGoblin.

Drop Privileges for MediaGoblin

As MediaGoblin does not require special permissions or elevated access, you should run MediaGoblin under an existing non-root user or preferably create a dedicated user for the purpose of running MediaGoblin. Consult your distribution’s documentation on how to create “system account” or dedicated service user. Ensure that it is not possible to log in to your system with as this user.

You should create a working directory for MediaGoblin. This document assumes your local git repository will be located at /srv/mediagoblin.example.org/mediagoblin/ for this documentation. Substitute your prefer ed local deployment path as needed.

This document assumes that all operations are performed as this user. To drop privileges to this user, run the following command:

su - [mediagoblin]

Where, “[mediagoblin]” is the username of the system user that will run MediaGoblin.

Install MediaGoblin and Virtualenv

Note

MediaGoblin is still developing rapidly. As a result the following instructions recommend installing from the master branch of the git repository. Eventually production deployments will want to transition to running from more consistent releases.

Issue the following commands, to create and change the working directory. Modify these commands to reflect your own environment:

mkdir -p /srv/mediagoblin.example.org/
cd /srv/mediagoblin.example.org/

Clone the MediaGoblin repository:

git clone git://gitorious.org/mediagoblin/mediagoblin.git

And set up the in-package virtualenv:

cd mediagoblin
(virtualenv --system-site-packages . || virtualenv .) && ./bin/python setup.py develop

Note

If you have problems here, consider trying to install virtualenv with the --distribute or --no-site-packages options. If your system’s default Python is in the 3.x series you may need to run virtualenv with the --python=python2.7 or --python=python2.6 options.

The above provides an in-package install of virtualenv. While this is counter to the conventional virtualenv configuration, it is more reliable and considerably easier to configure and illustrate. If you’re familiar with Python packaging you may consider deploying with your preferred method.

Assuming you are going to deploy with FastCGI, you should also install flup:

./bin/easy_install flup

This concludes the initial configuration of the development environment. In the future, when you update your codebase, you should also run:

./bin/python setup.py develop --upgrade && ./bin/gmg dbupdate

Note: If you are running an active site, depending on your server configuration, you may need to stop it first or the dbupdate command may hang (and it’s certainly a good idea to restart it after the update)

Deploy MediaGoblin Services

Configure MediaGoblin to use the PostgreSQL database

If you are using postgres, edit the [mediagoblin] section in your mediagoblin_local.ini and put in:

sql_engine = postgresql:///mediagoblin

if you are running the MediaGoblin application as the same ‘user’ as the database owner.

Update database data structures

Before you start using the database, you need to run:

./bin/gmg dbupdate

to populate the database with the MediaGoblin data structures.

Test the Server

At this point MediaGoblin should be properly installed. You can test the deployment with the following command:

./lazyserver.sh --server-name=broadcast

You should be able to connect to the machine on port 6543 in your browser to confirm that the service is operable.

Connect the Webserver to MediaGoblin with FastCGI

This section describes how to configure MediaGoblin to work via FastCGI. Our configuration example will use nginx, however, you may use any webserver of your choice as long as it supports the FastCGI protocol. If you do not already have a web server, consider nginx, as the configuration files may be more clear than the alternatives.

Create a configuration file at /srv/mediagoblin.example.org/nginx.conf and create a symbolic link into a directory that will be included in your nginx configuration (e.g. “/etc/nginx/sites-enabled or /etc/nginx/conf.d) with one of the following commands (as the root user):

ln -s /srv/mediagoblin.example.org/nginx.conf /etc/nginx/conf.d/
ln -s /srv/mediagoblin.example.org/nginx.conf /etc/nginx/sites-enabled/

Modify these commands and locations depending on your preferences and the existing configuration of your nginx instance. The contents of this nginx.conf file should be modeled on the following:

server {
 #################################################
 # Stock useful config options, but ignore them :)
 #################################################
 include /etc/nginx/mime.types;

 autoindex off;
 default_type  application/octet-stream;
 sendfile on;

 # Gzip
 gzip on;
 gzip_min_length 1024;
 gzip_buffers 4 32k;
 gzip_types text/plain text/html application/x-javascript text/javascript text/xml text/css;

 #####################################
 # Mounting MediaGoblin stuff
 # This is the section you should read
 #####################################

 # Change this to update the upload size limit for your users
 client_max_body_size 8m;

 # prevent attacks (someone uploading a .txt file that the browser
 # interprets as an HTML file, etc.)
 add_header X-Content-Type-Options nosniff;

 server_name mediagoblin.example.org www.mediagoblin.example.org;
 access_log /var/log/nginx/mediagoblin.example.access.log;
 error_log /var/log/nginx/mediagoblin.example.error.log;

 # MediaGoblin's stock static files: CSS, JS, etc.
 location /mgoblin_static/ {
    alias /srv/mediagoblin.example.org/mediagoblin/mediagoblin/static/;
 }

 # Instance specific media:
 location /mgoblin_media/ {
    alias /srv/mediagoblin.example.org/mediagoblin/user_dev/media/public/;
 }

 # Theme static files (usually symlinked in)
 location /theme_static/ {
    alias /srv/mediagoblin.example.org/mediagoblin/user_dev/theme_static/;
 }

 # Mounting MediaGoblin itself via FastCGI.
 location / {
    fastcgi_pass 127.0.0.1:26543;
    include /etc/nginx/fastcgi_params;

    # our understanding vs nginx's handling of script_name vs
    # path_info don't match :)
    fastcgi_param PATH_INFO $fastcgi_script_name;
    fastcgi_param SCRIPT_NAME "";
 }
}

Now, nginx instance is configured to serve the MediaGoblin application. Perform a quick test to ensure that this configuration works. Restart nginx so it picks up your changes, with a command that resembles one of the following (as the root user):

sudo /etc/init.d/nginx restart
sudo /etc/rc.d/nginx restart

Now start MediaGoblin. Use the following command sequence as an example:

cd /srv/mediagoblin.example.org/mediagoblin/
./lazyserver.sh --server-name=fcgi fcgi_host=127.0.0.1 fcgi_port=26543

Visit the site you’ve set up in your browser by visiting <http://mediagoblin.example.org>. You should see MediaGoblin!

Note

The configuration described above is sufficient for development and smaller deployments. However, for larger production deployments with larger processing requirements, see the “Considerations for Production Deployments” documentation.