Installing Sun Java 6

Ensure the non-free section is enabled for the APT repository configuration in /etc/apt/sources.list, e.g. “deb http://ftp.de.debian.org/debian testing main contrib non-free”

apt-get update
apt-get install sun-java6-jdk
echo 'JAVA_HOME="/usr/lib/jvm/java-6-sun"' >> /etc/environment
echo 'JRE_HOME="/usr/lib/jvm/java-6-sun/jre"' >> /etc/environment

Installing Tomcat 6

apt-get install tomcat6 tomcat6-admin
/etc/init.d/tomcat6 stop

Creating standard Tomcat directory layout

mkdir /opt/tomcat
cd /opt/tomcat
ln -s /etc/tomcat6/ conf
ln -s /usr/share/tomcat6/bin/ bin
ln -s /usr/share/tomcat6/lib/ lib
ln -s /var/lib/tomcat6/webapps webapps
ln -s /var/log/tomcat6/ logs

Creating a Tomcat admin user

In /opt/tomcat/conf/tomcat-users.xml add an entry like:

<user name="ADMIN_USERNAME" password="ADMIN_PASSWORD" roles="admin,manager" />

Setting up virtual hosts

For each virtual host execute the following command. Replace “mydomain.com” with the desired virtual host name, but omit the “www.” part.

mkdir -p /opt/tomcat/webapps.mydomain.com/ROOT

In the <Engine> tag of “/opt/tomcat/conf/server.xml” add one host entry for each virtual host.

<Host name="mydomain.com" appBase="/opt/tomcat/webapps.mydomain.com">
    <Alias>www.mydomain.com>/Alias>
    <Valve className="org.apache.catalina.valves.AccessLogValve" prefix="mydomain_access_log." suffix=".txt" pattern="common"/>
</Host>

The <Alias> tag tells Tomcat to redirect from www.mydomain.com to mydomain.com.
The <Valve> tag enables access logging in the standard logging format.

Using xinetd to configure port 80 for Tomcat

Binding a service on port 80 requires root permissions. Thus we use port forwarding to “bind” Tomcat to port 80. My VPS does not support the use of “iptables -j REDIRECT” therefore I am using xinetd as a web proxy.
Ensure that no other service is listening on port 80/443:

netstat -pan | grep ":80\|:443"

Register the required xinetd services:

echo echo "
service www
{
        socket_type     = stream
        protocol        = tcp
        user            = root
        wait            = no
        bind            = 88.80.198.181
        port            = 80
        redirect        = localhost 8080
        disable         = no
        flags           = REUSE
        log_type        = FILE /var/log/wwwaccess.log
        log_on_success  -= PID HOST DURATION EXIT

        per_source      = UNLIMITED
        instances       = UNLIMITED
}

service https
{
        socket_type     = stream
        protocol        = tcp
        user            = root
        wait            = no
        bind            = 88.80.198.181
        port            = 443
        redirect        = localhost 8443
        disable         = no
        flags           = REUSE
        log_type        = FILE /var/log/httpsaccess.log
        log_on_success  -= PID HOST DURATION EXIT

        per_source      = UNLIMITED
        instances       = UNLIMITED
}
" > /etc/init.d/tomcat
/etc/init.d/xinetd restart

If you want to use a different service name, e.g. “tomcat” instead of “www” you must add this service to /var/services, e.g. “tomcat 80/tcp”
In /opt/tomcat/conf/server.xml modify the <Connector> as follows:

<Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" proxyPort="80" address="127.0.0.1" />

This binds Tomcat to localhost. It also tells Tomcat that port 80 is the proxy port which is necessary for correct URL generation.
From now on the Tomcat admin applications are only accessible via localhost. You can use SSH port forwarding to still access the applications from your workstation’s web browser. E.g. if you are using PuTTY you can use this command line option “-L 8080:localhost:8080″ to forward the server’s local 8080 port to your workstation’s local 8080 port. On your workstation’s browser you then simply enter http://localhost:8080/manager/html and are connected to the server’s Tomcat admin application.

Enabling PHP support (optional)

Download Quercus.

mkdir -p /opt/downloads
wget -o /opt/downloads/quercus-4.0.3.war http://caucho.com/download/quercus-4.0.3.war

Install Quercus as a shared library.

unzip -j /opt/downloads/quercus-4.0.3.war \*.jar -d /opt/tomcat/lib

Enable PHP support for the virtual hosts by installing the quercus web.xml. For each virtual host execute:

unzip /opt/downloads/quercus-4.0.3.war *web.xml -d /opt/tomcat/webapps.mydomain.com/ROOT

Starting Tomcat

/etc/init.d/tomcat start

References

• Securing Linux for Java services: The port dilemma
• Redirect HTTP and HTTPS traffic to Tomcat’s ports
• Tomcat 6: Virtual Hosting How To
• Tomcat 6: Classloader How To
• Virtual Hosting with Tomcat
• Quercus: Tomcat
• How to install Tomcat 6 on Ubuntu 9.04 (Jaunty)

© sebthom for sebthom.de, 2010. | Permalink | No comment | Add to del.icio.us
Post tags: Java, PHP, port 80, port forwarding, quercus, tomcat, vhost, virtual servers, VPS, xinetd

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$wp_taxonomies['category'] = (object) array('name' => 'category', 'object_type' => 'post', 'hierarchical' => true, 'update_count_callback' => '_update_post_term_count');
$wp_taxonomies['post_tag'] = (object) array('name' => 'post_tag', 'object_type' => 'post', 'hierarchical' => false, 'update_count_callback' => '_update_post_term_count');
$wp_taxonomies['link_category'] = (object) array('name' => 'link_category', 'object_type' => 'link', 'hierarchical' => false);

Since I don’t get any error messages neither on the screen nor in the log files I have no idea why these casts fail. The PHP version used to serve the site is the latest stable 5.x release from php.net.
As a workaround I introduced a function that does also transforms an array into an object but does not rely on the casting mechanism.

function arr2obj($arr) {
	foreach ($arr as $k => $v) $obj -> {$k} = $v;
	return $obj;
}

$wp_taxonomies['category'] = arr2obj(array('name' => 'category', 'object_type' => 'post', 'hierarchical' => true, 'update_count_callback' => '_update_post_term_count'));
$wp_taxonomies['post_tag'] = arr2obj(array('name' => 'post_tag', 'object_type' => 'post', 'hierarchical' => false, 'update_count_callback' => '_update_post_term_count'));
$wp_taxonomies['link_category'] = arr2obj(array('name' => 'link_category', 'object_type' => 'link', 'hierarchical' => false));

© sebthom for sebthom.de, 2008. | Permalink | One comment | Add to del.icio.us
Post tags: bug, PHP, Wordpress, workaround

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I am using the great DD Sitemap Generator Plug-in for WordPress  to automatically render a site map based on the posts, pages and categories created in my blog. The problem however is that the generated site map is not language aware and displays the page/post titles and category names including the tags and the texts of all languages at once.

To solve this I started digging a bit into the code of WordPress and the Language Switcher Plug-in. The Language Switcher Plug-in achieves the on-the-fly processing of multilingual texts by hooking itself into the so called Filters API which is something like an event-based callback mechanism. Plug-ins can signal their interest in a certain text filter event by calling the add_filter(the_event_id, the_name_of_a_function_to_callback) function provided by the WordPress API to register one if it’s functions that will be invoked by WordPress when the filter event occurs. Besides registering for filter events, plug-ins can also fire such events by calling the apply_filters(the_event_id, the_text_to_be_filtered). WordPress will then apply all registered filters to the text passed over and the apply_filters will return a “filtered” version of the passed text. When rendering the title of a post or page WordPress fires the filter event “the_title” allowing plug-ins to process/modify the title before it is actually displayed. Therefore the Language Switcher Plug-in registers itself to this event and a lot of others to be able to strip off the language tags and the texts in languages other than the currently active one.

Unfortunately the DD Sitemap Generator Plug-in is currently not applying the respective filters when rendering the site map. Therefore the Language Switcher Plug-in is not aware of it and as a result the site map shows all translations of a category name or page/post title at the same time no matter which language is currently active.

To solve this problem I analyzed the source code of the DD Sitemap Generator Plug-in and added the missing apply_filters calls where appropriate. You can follow these steps in case you are having the same issue:

1. Open the file <wordpress_root>/wp-content/plugins/sitemap-generator/sitemap-generator.php (or <wordpress_root>/wp-content/plugins/dd-sitemap-gen/dd-sitemap-gen.php) in an editor
2. Locate the text
      $tmp_array['title'] = $pages[$k]->post_title;
   and replace it with
      $tmp_array['title'] = apply_filters(‘the_title’, $pages[$k]->post_title);
3. Locate the text
      $tmp_array['title'] = $cat_data[$c]['cat_name'];
   and replace it with
      $tmp_array['title'] = apply_filters(‘the_category’, $cat_data[$c]['cat_name']);
4. Locate the text
      $tmp_array['title'] = $posts[$k]->post_title;
   and replace it with
      $tmp_array['title'] = apply_filters(‘the_title’, $posts[$k]->post_title);
5. Save the file and you are done.

If you are encountering similar problems with other plug-in you can use the same approach to make them play nicely with the Language Switcher Plug-in.

© sebthom for sebthom.de, 2008. | Permalink | 3 comments | Add to del.icio.us
Post tags: PHP, Wordpress, workaround

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To cut a long story short, eventually I came across this PHP bug report #42739 mkdir doesn’t like a trailing slash when safe_mode is enabled and it turned out that this was the issue I was facing with on my hosting account too. The safe_mode option is enabled and WordPress tries to create directories that end with a slash (e.g. /htdocs/wp-content/upgrade/the-plugin/).

After knowing the reason I could develop a workaround and finally got the one-click updater running. If you are facing the same issue you can try to use my patch too.

1. Locate and open the file <wp_root>/wp_admin/includes/class-wp-filesystem-direct.php in an editor
   
2. Search for “function mkdir”
   
3. Add the following statements to this method

   function mkdir($path,$chmod=false,$chown=false,$chgrp=false){
   	if( ! $chmod)
   		$chmod = $this->permission;
   
   	// workaround for http://bugs.php.net/bug.php?id=42739 starts here
   	if(ini_get('safe_mode') && substr($path, -1) == '/')
   	{
   		$path = substr($path, 0, -1);
   	}
   	// workaround for http://bugs.php.net/bug.php?id=42739 ends here
   
   	if( !@mkdir($path,$chmod) )
   		return false;
   	if( $chown )
   		$this->chown($path,$chown);
   	if( $chgrp )
   		$this->chgrp($path,$chgrp);
   	return true;
   }

4. Start one-click updating!

Addendum:

1. The patch also works for WordPress 2.5.1
2. If applying this patch does not lead to success the problem may have a second cause. Therefore also check the permissions on the /wp-content/upgrade/ folder and it’s sub folders, e.g. chmod them to 777. If the upgrade directory does not exist at all it may be sufficient to create it manually.

© sebthom for sebthom.de, 2008. | Permalink | 30 comments | Add to del.icio.us
Post tags: bug, PHP, Wordpress, workaround

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So I started looking for some tools that could simplify this process. I finally came across a handy software called myPodder provided for free by Podcast Ready. Podcast Ready provides an online catalog of available podcasts from different sources and to my surprise they also have that German radio station listed. The interesting thing about their software is the fact that you can directly install it onto your mobile audio player and have it launched automatically the moment it is connected to a computer. This means you can easily charge your player with new podcasts from any computer having an internet connection. Simply connect the player, wait for the program to launch, select some new podcasts and download them.
(...)
Read the rest of myPodder – a mobile podcatcher (0 words)

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Post tags: audio, PHP, podcasts

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Read the rest of My favorite WordPress Plug-ins & Resources (717 words)

© sebthom for sebthom.de, 2007. | Permalink | 3 comments | Add to del.icio.us
Post tags: audio, MP3, PHP, Wordpress

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Post tags: PHP, Wordpress

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(...)
Read the rest of MyPad v1.1.6 – a PHP Editor (123 words)

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Post tags: bug, My Freeware, PHP, Visual Basic

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