LAMP with ·dotmanila » Apache

Internal Server Error (500) From Your PHP Application

admin — Wed, 28 Jul 2010 03:29:05 +0000

Recently I was working on a script on a fresh virtual server. The script was pulled from a production server and was being actively used. When I try to run it on the test server, it was mysteriously not working, Apache access_log shows 500 HTTP response code, PHP log_errors is ON,even display_errors is set to ON but there were no errors being displayed or logged. Thoroughly deducing my .htaccess, Apache virtual host configuration and doing a sanity check on the application itself, the mysterious error was being caused by one PHP extension missing, in this case php-ldap.

/var/www/sites/mediaweb

FFMpeg-PHP: undefined symbol: php_gd_gdImageSetPixel

jervin — Fri, 02 Oct 2009 15:01:32 +0000

I was recently updating ffmpeg-php on one of our servers to the latest SVN release of the 0.6.3 branch. On a 64bit CentOS 5.3 with PHP 5.2.11, the extension compiled and installed fine however Apache will not load it and spit out the error below:

PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib64/php/modules/ffmpeg.so’ – /usr/lib64/php/modules/ffmpeg.so: undefined symbol: php_gd_gdImageSetPixel in Unknown on line 0

Surely enough, the GD extension was there, but why is ffmpeg complaining about not finding that shared symbol? Because, ffmpeg is loading first than GD (alphabetically) and such symbol has not been loaded. After adding the GD extension line on top of ffmpeg making sure it loads first the error went away and all is well again.

Do you favor a “LAMP (Linux, Apache, PHP, MySQL) Integrator”?

jervin — Sun, 02 Aug 2009 03:41:16 +0000

I have been reading on a number of project management articles lately and trends on open source projects. There seems to be a lot of fellow PHP developers who are as well Linux administrators for many server functions inluding HTTP servers like Apache and database administrators like for MySQL. Many of them are certified for one or more while many are jumping between careers that emphasizes one to the other thus gaining essential experiences for each.

Looking at job posts from all over the internet, you should’ve noticed at one time a PHP gig that requires MySQL administration skills and/or knows their way around Linux. PHP does not come by itself anymore, at least commonly, thus I’ve thought the term “LAMP Integrator”. A quick Google search does not seem to turn much on how to define such, thus I have a simple one.

LAMP Integrator – is a PHP developer primarily using MySQL as data backend with strong Linux administration and Apache tuning skills.

It may sound primitive, I am writing as I am thinking so comments and revisions are welcome.

Gumblar .cn – Infiltrating Hosting Accounts

jervin — Wed, 20 May 2009 11:46:15 +0000

Hosting accounts being compromised has been a common incident, however a sudden surge of this variant is quite alarming. This trojan does not target any particular software or script and is commonly exploited from a users computer where he usually FTP files to hosting accounts. The trojan scans for FTP usernames and passwords and use them to inject PHP scripts to the FTP server.

So far I have seen two variations, one being a slave for XSS attack and another as proxy or zombie perhaps for a DoS attack.

What to do or how do you know if you are infected? There is no simple prevention measure I can offer aside from asking you to scan and thoroughly clean your computer first. Download all your files from the ftp server, you can do PHP files only, however there is a probability a JS based file may exist as well. After downloading, scan all your files and reupload. Not too neat but it’s the only method that works for me.

Cloak PHP Files as Directories and Force Trailing Slash via mod_rewrite

jervin — Wed, 06 May 2009 11:43:51 +0000

In an effort to turn a client’s website to be more SEO friendly, they wanted to have all PHP files appear as directories on URLs i.e. http://dotmanila.com/blog/php-cloak-and-force-traling-slash.php will end up as http://dotmanila.com/blog/php-cloak-and-force-traling-slash/. We’ve thought of creating a simple controller combined with mod_rewrite to handle this change on their 30+ websites, however it’ll be inefficient to use a two-fold process. So we toyed with mod_rewrite and came up below.

Options +FollowSymLinks
RewriteEngine On

RewriteBase /

# These first set of rules makes sure that visitors
# are viewing the WWW domain i.e. www.dotmanila.com
Rewritecond %{HTTP_HOST} !^www\.dotmanila\.com
RewriteRule (.*) http://www.dotmanila.com/$1/ [R=301,L]

# The next set of rules checks that if the URL
# does not have a trailing slash and
# the requested file/directory when appended
# with the .php extension physically exist on the server
# the we will append a traling slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ http://www.dotmanila.com/$1/ [L,R=301]

# The last set of rules makes sure that if
# the requested URL is in proper format the
# corresponding PHP file is mapped.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*)/$ /$1.php [NS,L]

Cheers!

mod_perlite: Reviving an old part of the dynamic web.

jervin — Thu, 15 Jan 2009 11:33:14 +0000

Back in the 90′s, when the web was new and anything dynamically scripted is ever exciting, CGI scripts takes the role.As the web evolved, mod_perl made it simpler for programmers to write highly capable web applications. And indeed the web is constantly evolving. With the advent of PHP and its upload and run deployment, it took the lead with statistics.

But Perl and CGI scripts may not be lagging behind forever, with the development of mod_perlite, an Apache module the matches deployment simplicity of that of PHP, Perl may again be on the rise.

From its freshmeat.net project page, the creators Aaron Stone and Byrne Reese describes:

mod_perlite is a lightweight Apache module that embeds a Perl interpreter and suggests a default configuration where any file ending in “.pl” is interpreted by Perl. It is the Perl equivalent of PHP in its simplicity and nothing like mod_perl in its complexity.

I believe truly, these is one of the 5 things Perl absolutely needs to gain more adaptations from new breeds. As chromatic from the O’Reilly blog network writes on his article Five Features Perl 5 Needs Now:

mod_perlite, the equivalent of mod_php for Perl. mod_perl is an amazing piece of technology, but it asks a lot of administrators — it effectively takes over the web server. Perl on the web could benefit from a system which allows cheap hosting providers to say “Just upload a few files into this directory, and everything will happen for you automatically!” without worrying about other customers on the same host fighting for resources (or namespaces or memory or…).

Very Serious Developers may still use mod_perl — but novices and the rest of us who aren’t handling more than a hit per second at peak time should have something easier to set up and gentler on resources than CGI.

There are many programming languages out there, and many would argue popularity is a major factor for adaptation. I’d agree most of the time, as soon as mod_perlite hits your local repository shelves Perl could again gain the internet buzzwords.