The other day this box went down and I could not access my Mediawiki installation. The box was meant to come back online later on but I really wanted to read the wiki, now. Luckily I had somewhat fresh backups from the mediawiki installation - so why not using them? Just to see how quickly a full restore would take.

So I fired up an openSUSE 12.1 installation, running in a virtual machine. The base system was already installed, a few more packages were needed now:

zypper install nginx mysql-community-server php5-fpm php5-mysql php5-intl php5-gd

Note: Mediawiki likes to utilize object caching, such as xcache or APC. However, PHP modules for openSUSE like php-APC or php5-xcache are only available via extra repositories. For the sake of simplicity, let's skip those now.

With these packages installed, their configuration comes next. This may be a bit openSUSE centric and other distributions may work differently.

For PHP-FPM, only the following parts were changed from its original configuration:

 $ cp -p /etc/php5/fpm/php-fpm.conf{.default,}
 $ cat /etc/php5/fpm/php-fpm.conf
 [...]
 [global]
 pid       = /var/run/php-fpm.pid
 error_log = /var/log/php-fpm.log
 
 [www]
 listen    = /var/run/php5-fpm.sock
 user  = nobody
 group = nobody
 pm = dynamic
 pm.max_children = 50
 pm.start_servers = 20
 pm.min_spare_servers = 5
 pm.max_spare_servers = 35

Enable and start PHP-FPM:

chkconfig php-fpm on && service php-fpm start

Next up is nginx. A very basic configuration:

 $ cat /etc/nginx/nginx.conf
 user                    nginx;
 worker_processes        1;
 error_log       /var/log/nginx/error.log;
 pid             /var/run/nginx.pid;
 
 events {
        worker_connections      1024;
        use                     epoll;
 }
 
 http {
        include         mime.types;
        default_type    application/octet-stream;
        access_log      /var/log/nginx/access.log;
 
        # This will access our PHP-FPM installation via a socket
        upstream php5-fpm-sock {
                server          unix:/var/run/php5-fpm.sock;
        }
 
   server {
        listen          80;
        server_name     suse0.local;
        root            /var/www;
        index           index.html index.php;
        autoindex       on;
        access_log      /var/log/nginx/suse0.access.log;
 
        location ~ \.php?$ {
                try_files $uri =404;
                include fastcgi_params;
                fastcgi_pass php5-fpm-sock;
                fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                fastcgi_intercept_errors on;
         }
   }
  }

Enable and start nginx (and MySQL):

  $ chkconfig nginx on && service nginx start
  $ chkconfig mysql on && service mysql start

By now we should have a working webserver, able to serve PHP pages. Now to the actual Mediawiki installation:

  $ cd /var/www
  $ wget http://download.wikimedia.org/mediawiki/1.20/mediawiki-1.20.0.tar.gz{,.sig}

Import their GPG keys and verify the signature:

  $ wget https://www.mediawiki.org/keys/keys.txt -O - | gpg --import 
  $ gpg --verify mediawiki-1.20.0.tar.gz.sig

Unpack:

  $ tar -xzf mediawiki-1.20.0.tar.gz 
  $ ln -s mediawiki-1.20.0 mediawiki
  $ cd mediawiki

With that in place, we could go to http://suse0.local/mediawiki/ and use the install wizard to install a basic, but empty Mediawiki. Once this is done, we restore a few things from our backup:

  $ tar -C ../backup/mediawiki/ -cf - LocalSettings.php extensions images | tar -xvf -
  $ bzip2 -dc ../backup/DB_wikidb.sql.bz2 | mysql -D wikidb

In our case, a few modifications to LocalSettings.php had to be made:

 # We have not yet set up any rewrite rules so short urls
 # won't work for now
 ## $wgArticlePath               = "/wiki/$1";
 
 # Disable this one for now
 ## $wgServer              = "https://www.example.org";
 
 # Our database details are different of course:
 $wgDBtype           = "mysql";
 $wgDBserver         = "127.0.0.1";
 $wgDBname           = "wikidb";
 $wgDBprefix         = "mw_";          # Our original database used a table prefix!
 $wgDBuser           = "root";
 $wgDBpassword       = "s3cr3t";
 
 # no APC/Xcache for openSUSE just now
 ## $wgMainCacheType       = CACHE_ACCEL;

Also: check those ''extensions'' or disable them if things don't work as expected.

Now, let's run the update.php script, to address any version differences of our new Mediawiki instance:

  $ php maintenance/update.php --conf `pwd`/LocalSettings.php

Done! The Mediawiki installation should now work. If it doesn't, try to set a few more things in LocalSettings.php:

 # At the very top:
 error_reporting( E_ALL | E_STRICT );
 ini_set( 'display_errors', 1 );
 
 $wgShowExceptionDetails        = true;
 $wgShowSQLErrors               = true;

Good luck! :-)