the

Little Projects

of Shawn M. Jones

I smacked my head on this one, seeing as one of my previous posts had the same solution.

CentOS 5 does not install php-mysql by default. When the WordPress installation runs, it disables error reporting for certain functions, presumably so that they can be dealt with later.

Unfortunately, this error reporting doesn’t get dealt with correctly, and instead the end user is presented with a blank page instead of a message telling them that the mysql functions don’t exist.

I’ve got a patch ready for the WordPress folks, but I’m still waiting for my login to their bug reporting system so I can submit it.

I hope this helps someone else.

In short, if you see a blank screen after putting in your database information during install, make sure that the php-mysql package is installed on CentOS. I spent hours trying to figure out why this wasn’t working right.

A year ago, after much consideration of differing tools, I looked at all of the open source Content Management Solutions and came to the conclusion that nothing solved every one of my needs well.

I needed the following:

1. A blog
2. A photo gallery
3. A web mail program

I tried quite a few solutions and came down to the following solutions that seemed to do their respective jobs best:

• A blog – B2Evolution
• A photo gallery – Gallery 2
• A web mail program – Squirrelmail

Then I ran into the following problems:

• No common authentication scheme for these three tools. In essence I had to log into each of them separately. This is a common problem to using multiple tools.
• A strange Out Of Memory error that occurs on my Apache web server when it runs too long. I don’t know if it’s B2 Evolution or Gallery 2 doing that. Currently the web server restarts its process every hour to avoid this (not really an optimal solution, don’t visit at the top of the hour)
• Squirrelmail has many of the features I want, but the interface is lacking.
• No way of tying the information together. I can not use the same categories for blog entries, photos, and email messages together. This was not an original requirement but became more apparent over time as I began using other tools, like Agendus on my PDA.
• PHP seems to have quite a few security holes, requiring a lot of patching/restarts of the web server.

So, with the hubris that most developers have, I decided it would be better to just write my own tools to do this.

I have looked at the following programming environments:

• Ruby on Rails – A Ruby Application Server for web development
• Zope – Like Ruby on Rails, but in Python
• J2EE – A web programming environment for Java

Each has its own pros and cons. Both Zope and Ruby on Rails appear to be very much tied to database design and relationships. J2EE is looking like a good choice for complete abstraction, but with that power comes a lot of work.

Then, there is the research needed to make certain aspects of blogs and photo galleries work.

In order to understand the implementation of Trackbacks and other Blog-related concepts, I’ll end up diving into B2Evolution’s code. In order to find out how caching is handled for photos, I’ll end up diving into Gallery 2’s code.

At that point, I might as well force those tools to do what I want.

Note my favicon:

I had been meaning to add a favicon (note the icon next to my address in the address bar on your browser) for quite some time, but hadn’t gotten around to it. The last time I tried to create something in the .ico format, I needed a special tool.

But then again, times change. I used the GIMP to make the .ico file and posted it to the root of my webserver directory.

Nothing happened when I refreshed the page.

Then I found out that I needed to tell Apache about .ico files, so I put the following in my /etc/httpd/conf/httpd.conf file:

AddType image/x-icon .ico

Make sure that the favicon.ico file has the executable bit set for everyone:

chmod a+x

and now it will show up.

You might need to clean out your cache and restart your browser to see it. Evidently this feature "sticks" to web pages.

If the Tikiwiki install generates a blank screen, it could be (it was for me) because you don’t have the php-mysql package installed.

CentOS 5 does not install the php-mysql package by default.

This is required by Tikiwiki if you are using mysql (obviously).

Setting up user directories for Apache (i.e. ~user) on CentOS 5:

1. Change the /etc/httpd/conf/httpd.conf and comment out:

   UserDir disable

   and un-comment:

   UserDir public_html

2. Restart Apache.
3. Create a public_html directory in the user’s home directory.
4. Make sure it has permissions 0755.
5. Make sure their home directory has permission 0711.
6. Make sure that public_html directory has SELinux context:

   user_u:object_r:httpd_sys_content_t

7. Make sure that the SELinux boolean

   httpd_enable_homedirs

   is set to "on".