WordPress MU Upgrade and Permalinks 404 Erros

Posted on November 25, 2011 by admin

WordPress MU upgrade(from 2.x to 3.2.1) was a rather simple process surprisingly! Having completed it in a matter of couple hours for a fairly large blogging network, I was a happy camper up till the moment when permalinks started giving 404s.

What followed is painstaking process where I verified everysingle aspect of configuration from Apache’s mod_rewrite setup to htaccess rules to WordPress’s network site configs. Everything looked correctly.

Googling around for a good hour I came across this site, which pointed to the incompatibility of some plugins with WP3. In my case problem lied in a plugin called Top Level Categories, which I had to disable to get the permalinks working.

Posted in Just messing... | Tagged | Leave a comment

MongoDB distinct count

Posted on September 15, 2011 by admin

List of disctinct values for a FIELD in COLLECTION:
db.COLLECTION.distinct("FIELDNAME", {})

Count of the same:
db.COLLECTION.distinct("FIELDNAME", {}).count

Posted in 4QuickLookUp | Leave a comment

How to install Xapian 1.2.5 PHP bindings on Ubuntu Lucid Lynx

Posted on June 27, 2011 by admin

Starting from version 1.2.x, Xapian repository on Ubuntu does not contain php5-xapian package :( apparently due to the license incompatability between GPL and PHP license(great…)
Issue is discussed somewhat at length here.

But in the meantime, folks suggesting to build PHP bindings for Xapian manually on Ubuntu and Debian. Here is a quick command trail that shows how to install Xapian 1.2.5 PHP bindings on Ubuntu Lucid(10.04), also tested on Ubuntu 10.10 and 11.04:

1. Edit /etc/apt/sources.list and add the following lines to it:

deb http://ppa.launchpad.net/xapian-backports/xapian-1.2/ubuntu lucid main
deb-src http://ppa.launchpad.net/xapian-backports/xapian-1.2/ubuntu lucid main

2. Get some required packages:

sudo apt-get update
sudo apt-get build-dep xapian-bindings
sudo apt-get install php5-dev php5-cli
sudo apt-get install devscripts

3. Fetch sources and build:

apt-get source xapian-bindings
cd xapian-bindings-1.2.5
rm debian/control
env PHP_VERSIONS=5 debian/rules maint
debuild -e PHP_VERSIONS=5 -us -uc

This will generate .deb file in the folder, one level up.

4. Finally, install php5-xapian extenstion:

cd ..
sudo dpkg -i php5-xapian*.deb

5. Verify that you got it running:

php -i | grep Xapian

Information about this process is taken from here and here.

Posted in Linux/UNIX, Notes For Myself, PHP, System Administration | Leave a comment

Auto-splitting video file in equal chunks with ffmpeg and python

Posted on April 15, 2011 by admin

Recently I needed to upload a whole bunch of long video files. Maximum allowed length for each video was just few minutes, while the actual length of files I tried to upload were about an hour each. FFmpeg is really great for splitting the video files and Python is quite handy for automating the task. Combining two together in this handy little script(see below). The script below takes a video file and a chunk size in seconds and splits the video file into chunks using ffmpeg, so each chunk is self contained, playable video.

Source code:

#!/usr/bin/env python

import subprocess
import re
import math
from optparse import OptionParser

length_regexp = 'Duration: (\d{2}):(\d{2}):(\d{2})\.\d+,'
re_length = re.compile(length_regexp)

def main():

    (filename, split_length) = parse_options()
    if split_length <= 0:
        print "Split length can't be 0"
        raise SystemExit

    output = subprocess.Popen("ffmpeg -i '"+filename+"' 2>&1 | grep 'Duration'",
                            shell = True,
                            stdout = subprocess.PIPE
                            ).stdout.read()
    print output
    matches = re_length.search(output)
    if matches:
        video_length = int(matches.group(1)) * 3600 + \
                        int(matches.group(2)) * 60 + \
                        int(matches.group(3))
        print "Video length in seconds: "+str(video_length)
    else:
        print "Can't determine video length."
        raise SystemExit

    split_count = math.ceil(video_length/float(split_length))
    if(split_count == 1):
        print "Video length is less then the target split length."
        raise SystemExit

    split_cmd = "ffmpeg -i '"+filename+"' -vcodec copy "
    for n in range(0, split_count):
        split_str = ""
        if n == 0:
            split_start = 0
        else:
            split_start = split_length * n

        split_str += " -ss "+str(split_start)+" -t "+str(split_length) + \
                    " '"+filename[:-4] + "-" + str(n) + "." + filename[-3:] + \
                    "'"
        print "About to run: "+split_cmd+split_str
        output = subprocess.Popen(split_cmd+split_str, shell = True, stdout =
                               subprocess.PIPE).stdout.read()

def parse_options():
    parser = OptionParser()    

    parser.add_option("-f", "--file",
                        dest = "filename",
                        help = "file to split, for example sample.avi",
                        type = "string",
                        action = "store"
                        )
    parser.add_option("-s", "--split-size",
                        dest = "split_size",
                        help = "split or chunk size in seconds, for example 10",
                        type = "int",
                        action = "store"
                        )
    (options, args) = parser.parse_args()

    if options.filename and options.split_size:

        return (options.filename, options.split_size)

    else:
        parser.print_help()
        raise SystemExit

if __name__ == '__main__':

    try:
        main()
    except Exception, e:
        print "Exception occured running main():"
        print str(e)

Or download it here: splitting video file script link

Posted in Notes For Myself, Python | Tagged , | 3 Comments

Build OpenLDAP 2.3.x from sources on Ubuntu

Posted on April 12, 2011 by admin

It happened so that I needed to build a particular version of OpenLDAP on Ubuntu and use that instead of the one in Ubuntu’s repository. Here is a quick guide as to how it worked for me:

1. Get BDB 4.3 sources from Oracle’s site(link)

2. Compile BDB and install it:

tar –xvzf db-4.3.29.tar.gz
cd db-4.3.29/build_unix
./configure --prefix=/usr/local/bdb43
make
sudo make install

3. Get OpenLDAP source(ftp link)
4. Compile and install it:

tar xzvf openldap-2.3.35.tgz
cd openldap
export CPPFLAGS="-I/usr/local/bdb43/include -D_GNU_SOURCE"
export LDFLAGS="-L/usr/local/lib -L/usr/local/bdb43/lib -R/usr/local/bdb43lib"
export LD_LIBRARY_PATH="/usr/local/bdb43/lib"
./configure --prefix=/usr/local/openldap

If you’re installing version 2.3.x or anything before 2.4.15 you will need to manually patch OpenLDAP otherwise you’ll get this error:
../../include/ldap_pvt_thread.h:64: error: missing binary operator before token “(“
Patch file is available in this bug report
Or already patched file for OpenLDAP version 2.3.35 you can download here

If you’re installing anything >= 2.4.15, you can skip the patch.

Once patch is applied just run:

make depend
make
make test  #this will take a while to run
make install

Common Errors:
configure: error: Berkeley DB version mismatch
Solution: Most likely you didn’t LDFLAGS and LD_LIBRARY_PATH as noted above

getpeereid.c:52: error: storage size of ‘peercred’ isn’t known
You need to include -D_GNU_SOURCE flag, to avoid incompatibility with glibc

../../include/ldap_pvt_thread.h:64: error: missing binary operator before token “(“
Solution: Apply patch as noted above

error while loading shared libraries: libdb-4.3.so: cannot open shared object file: No such file or directory
Solution: Add libdb-4.3 to shared libs cache:

sudo echo "/usr/local/bdb43/lib" > /etc/ld.so.conf.d/slapd.conf
lddconfig -v
Posted in Linux/UNIX, Notes For Myself, System Administration | Tagged , , , , | 5 Comments

Getting around open_basedir restriction on Plesk

Posted on March 19, 2011 by admin

Almost every time I do a deploy on Plesk-based hosting server, I hit the same roadblock:

PHP Warning:  realpath() [<a href='function.realpath'>function.realpath</a>]: open_basedir restriction in effect.

Since I tend to keep my app-code outside of webroot, this restriction is somewhat a problem. Well, luckily, the fix is simple enough.

1. Add file vhost.conf to /var/www/vhosts/YOURDOMAIN/conf folder with the following:

<Directory /var/www/vhosts/YOURDOMAIN/httpdocs/>
<IfModule sapi_apache2.c>
php_admin_value open_basedir none
</IfModule>
<IfModule mod_php5.c>
php_admin_value open_basedir none
</IfModule>
</Directory>

2. Reload server configuration, either via Plesk admin or through CLI:

/usr/local/psa/admin/sbin/websrvmng -u --vhost-name=yourdomain

Posted in Notes For Myself, PHP | Tagged | 1 Comment

HTML5 Video Encoding with FFmpeg

Posted on March 10, 2011 by admin

Encoding Ogg video

ffmpeg -i SOURCEFILE.avi -vcodec libtheora OUTFILE.ogg

Encoding MP4

ffmpeg -i SOURCEFILE.avi -vcodec libx264 -vpre slow OUTFILE.mp4

Encoding WebM

ffmpeg -i SOURCEFILE.avi -vcodec libvpx -acodec vorbis  OUTFILE.webm

Resizing video:

ffmpeg -i SOURCEFILE.avi -s WIDTHxHEIGHT OUTFILE.ogg

WIDTH, HEIGHT new width and height in pixels.

Posted in Notes For Myself | Tagged , , , | Leave a comment

Gnome Do, Docky, upgrade to Ubuntu 10.10 and an odd case of /var/lib/dpkg/tmp.ci/md5sums

Posted on February 13, 2011 by admin

So I finally upgraded to 10.10, a bit behind the curve but whatever. For the most part it went surprisingly swimmingly. I only had 2 issues :)

First one – gnome-do docky theme was gone. And apprently it’s gone for good and now it is a separate project. Fix is as simple as:


sudo apt-get install docky

Fixed that right away.

Second issue was a bit more annoying. Problem was with updating linux-firmware package. For some reason dpkg was throwing and error saying that ‘/var/lib/dpkg/tmp.ci/md5sums: Is a directory‘. After messing around fix for that was basically this:

sudo bash
cd /var/lib/dpkg/info
rm -rf linux-firwmare*
apt-get upgrade

What happen is /var/lib/dpkg/info/linux-firmware.md5sums got corrupted and instead of being a file it became a directory point to postfix’s folder(in my case). I had some hard drive issues few weeks ago, so probably fsck did this… oh well, can’t blame it :)

Posted in Just messing..., Linux/UNIX | Tagged | 1 Comment

WordPress shortcode for ShareThis buttons

Posted on February 5, 2011 by admin

I like using ShareThis for social sharing button, but one thing that was certainly missing for the default ShareThis WordPress plugin were shortcodes. Luckily WordPress makes it really easy adding them :) So to get shortcode for ShareThis integration just add the following few lines to the end of the functions.php in your theme folder:

/**
* Creates sharethis shortcode
*/
if (function_exists('st_makeEntries')) :
add_shortcode('sharethis', 'st_makeEntries');
endif;

Once that’s done you can use [sharethis] shortcode anywhere on the page/post to get sharing buttons rendered there. Short and sweet :)

Posted in PHP | Tagged , | 3 Comments

How to setup local PHP debugging with PHPStorm and Xdebug

Posted on December 30, 2010 by admin

I am checking out a new IDE on the block – PHPStorm… well, new for me anyway :)

For Java and Python, Eclipse is all I need, but when coding in PHP, I am not a big IDE guy, for me, Vi is still the weapon of choice. But when it comes to debugging complex apps(yeah you can write those in PHP too :) , Vi doesn’t quite cut it. There are plugins for it to provide debugging capabilities(or rather Vimified interface to Xdebug), but half of the time it doesn’t work and the other half of the time it’s not what I am looking for. So far, I’ve been a user of Komodo IDE, I still have the old version 4 up and running here and do most of my debugging in it. It’s nice on one side, but somewhat cumbersome on the other.

Anyway, one major thing that always kept me from trying new IDEs is debugger setup. I tend to spend 10 minutes trying to setup debugging in new IDE, get frustrated, say fuck it, and get back to Komodo. This short blog post is to capture how I setup debugging in PHPStorm using Xdebug.
There is a video about this as to how to get a remote debugging working, but not much info about how to get a local one for folks who is on Linux(Ubuntu in my case).
So there we go:

Xdebug Setup

Step 0. Get phpize. If you’re on Ubuntu it’s as simple as running sudo apt-get install php5-dev
Step 1. Get Xdebug, it’s pure awesomeness. Just go here: http://xdebug.org/find-binary.php and follow the instructions. Note: you can also try installing it from pecl or Ubuntu repository, but I had problems with these methods before.
Step 2. I recommend not to follow the last step of Xdebug install instructions where it says to add zend_extension line to the php.ini file. Cleaner way of enabling Xdebug and then configuring it is to add a file xdebug.ini to /etc/php5/conf.d/ folder with the following contents:

;xdebug configuration
zend_extension = /usr/lib/php5/20090626/xdebug.so
xdebug.remote_host = 127.0.0.1
xdebug.remote_enable = 1
xdebug.remote_port = 9000
xdebug.remote_handler = dbgp
xdebug.remote_mode = req

This xdebug.ini will be picked up by both CLI and Apache and makes it easier to control without messing with the central config file.
Once apache is restarted and xdebug succesfully loaded, time to look at phpStorm’s side.

Step 3. Get Xdebug helper extension for Chrome or similar for Firefox is very handy. Get one so you can enable/disable debugging sessions from the browser. Make sure you set it up such that is loads up on your local domain. For example, if your project runs on myproject.local, your setup will prob look like this:

PHPStorm Debugging Setup

This is a bit less straightforward, but here I go anyway. Here are my assumptions:
My project is running localy at http://myproject.local
It’s stored locally in /home/user/Projects/myproject/public ,which is also a DocumentRoot for myproject.local Vhost config in Apache. There are ‘library’ and ‘application’ folders outside of DocRoot however.

Step 1. In PHPStorm, setup path to web browser(File->Settings->Web Browsers). It actually detected all paths correctly except for Chrome, which I had to set manually(in my case it was in /usr/bin/google-chrome)

Step 2. Setup run configuration – Run->Edit Configurations. That screen is kinda odd, but here is how I got it going.
* Create new configuration, with type PHP on Server

* Create new server(click on the … button next to “Server” dropdown). I picked server type “Local” and set webroot to “http://myproject.local“. On the “Mappings” tab I set local path to /home/user/Projects/myproject/public
* Save that server and select it in the Run Configurations
Ultimately my config looked as following:

This looks like it. Now opening up a file inside that project and ‘running’ it will actually bring up a new Chrome window with a page and put PHPStorm in listening mode on port 9000 for Xdebug connections. You’ll need to activate ‘Xdebug helper’ in that window, after that all interactions with the server will be intercepted by Xdebug and PHPStorm.

Posted in PHP | Tagged , , , , , | 14 Comments