Fix websocket configuration

Enable the proxy_websocket module.

Correct the ProxyPass directives in use with websockets.  The
current versions result in 404 on socket.io.js because they strip
the socket.io component of the path.

Change-Id: I3505b4e9693602ec04baec2487871ce57a6dc7a6

manifests/apache.pp

@@ -58,6 +58,10 @@ class etherpad_lite::apache (
       notify  => Service['httpd'],
       require => File['/etc/apache2/conf-available/connection-tuning'],
     }
+
+    httpd_mod { 'proxy_wstunnel':
+      ensure => present,
+    }
   }
 
   file { $docroot:

templates/etherpadlite.vhost.erb

@@ -74,8 +74,8 @@
           RewriteCond %{REQUEST_URI}  ^/socket.io            [NC]
           RewriteCond %{QUERY_STRING} transport=websocket    [NC]
           RewriteRule /(.*)           ws://localhost:9001/$1 [P,L]
-          ProxyPass        /socket.io http://localhost:9001 retry=0
-          ProxyPassReverse /socket.io http://localhost:9001
+          ProxyPass        /socket.io http://localhost:9001/socket.io retry=0
+          ProxyPassReverse /socket.io http://localhost:9001/socket.io
       </IfModule>
 
       ProxyPass  / http://localhost:9001/ retry=0