Reactivating

It's been years since my last post. It seems that I can't blog when I don't put my heart in it.
Let's see if I can reignite the sparks.

How to Make an Offline Repository of Your Own Ubuntu System

Introduction

Sometimes when you need to replicate an Ubuntu system to another computer, the usual step will be:

1. Install Ubuntu using Installer CD/ Live CD
2. Reboot
3. Connect to the Internet
4. Update
5. Installing additional packages that you need

However, if it occurs that you need to install to another computer at another place with uncertainty of the availability and/or reliability of the Internet connection over there, one would wonder if you could prepare those updates and additional packages yourself in an offline repository.

Assuming the additional packages is the same with your Ubuntu System, this howto will explain how to make such offline repository.

Creating Offline Repository

There are 4 steps to setting up a simple repository for yourself

1. Import the packages in a directory
2. Scan the packages and create a file apt-get update can read
3. Replicate the repository to portable media
4. Add a line to your sources.list pointing at your repository

Import Packages

In your Ubuntu System, the .deb files you have installed are stored in /var/cache/apt/archives/

To replicate these files, first create the directory you want to paste into. For this example, we'll use ~/mydebs.

mkdir ~/mydebs

Then, replicate the files using rsync

rsync -upt --progress /var/cache/apt/archives/*.deb ~/mydebs

Sometimes some files you have installed is not cached. If so, you need to retrieve them from the internet. First we need to generate the list of files to be downloaded.

sudo apt-get install $(dpkg -l|grep ^ii|awk '{print $2}') --reinstall --print-uris \

-y |awk '{print $1}'|sed "s/'//g"|grep tp:// > downlist

Then download it using wget

wget -ci downlist -P ~/mydebs

Scan Packages

To be included in apt-get process, we net to generate packages list of those .deb files.

First go into mydebs directory.

cd ~/mydebs

then generate Packages.gz using dpkg-scanpackages

dpkg-scanpackages . /dev/null | gzip -9c > Packages.gz

Replicate mydebs Directory to Portable Media

The repository can now be replicated to portable media, such as DVD-ROM or External Hard Drive. Assuming you are using external harddrive with volume name REPO:

rsync -a ~/mydebs /media/REPO/mydebs

Then, after finishing installing the new system, restore the directory to your new home folder

rsync -a /media/REPO/mydebs ~/mydebs

Adding mydebs Directory as Repository Source

To use these repository, these mydebs directory then must be included in the Repository Source file on your new system.

sudo su -pc 'echo deb file:$HOME/mydebs ./ >> /etc/apt/sources.list'

sudo apt-get update

Your repository is now ready to use

Counting Down on Intrepid Ibex

I just can't wait :-D

Extracting Similarity Between Two (Text) Files

When you need to compare difference between two files, you have diff.
When you need to find similarity between such files, as far as I know, you need to devise your own script.
This is my oneliner script for such need (assuming files to be compared named file-01 & file-02):

for ((i=1;i<=$(wc -l file-01|awk '{print $1}');i+=1)); do grep $(awk -v a=$i 'NR==a' file-01) file-02 ; done

Ugly, but working...

The Reason

If I know the answer of "Why",
I believe I'll better understand the question of "How"

I need to know why I want to be rich, before seeking the way to be richer
I need to know why I want to be free, before breaking anything that hold me back
I need to know why I want to be happy, before pursuing the happiness itself

But, is it wise to seek the reason of being right, while I am still pursuing the very question of what is truth?

Reverse Proxy with Apache

Sometimes, when we need to configure network devices within LAN (via http), we need to do it on site due to private addressing. While making the devices directly accessible from the Internet is a big no-no, there is another way to connect remotely and securely: Reverse HTTP Proxy (with Apache).

Apache has proxy-related modules to enable this operation. To get it working, you need to enable this modules:
- proxy
- proxy_http

Using Ubuntu 7.10, this modules can be loaded simply by typing:

sudo a2enmod proxy
sudo a2enmod proxy_http
sudo /etc/init.d/apache2 restart

To forward any http request to your internal address, you need to add the destination url into your virtual host configuration, i.e:

sudo nano /etc/apache2/sites-available/yourvirtualhostconfig

then add this line:

ProxyPass /your-public-url/ http://your-private-address

enable your site by typing:

sudo a2ensite yourvirtualhostconfig
sudo /etc/init.d/apache2/restart

By default, in Ubuntu 7.10 all proxy access are denied. Therefore, you
need to white list your address into the proxy.conf file

sudo nano /etc/apache2/mods-available/proxy.conf

change the config to allow your source address i.e:

<Proxy *>
AddDefaultCharset off
Order deny,allow
Deny from all
Allow from 203.153.240.197
</Proxy>

Then reload the configurations

sudo a2enmod proxy
sudo /etc/init.d/apache2 restart

That's it folks. Enjoy working on your devices remotely, securely.
(It is not so secure as the traffic is not encrypted. What I mean by
secure, is that I can hide the private address from any port scan.
Therefore, what is deemed secure by me, is not necessarily secure by
your definition. This is MY blog, so no complain!!!)

Connecting to XL 3G via Sony Ericsson W850i

While it is not so newbie friendly, I never thought that configuring Internet connectivity using my cellular phone will be a straightforward process. All I did just edit the /wtc/wvdial.conf into this:

Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0

Modem Type = USB Modem
Baud = 460800
Modem = /dev/ttyACM1
ISDN = 0
Phone = *99***1#
Phone1 = *99***2#
Password = proxl
Username = xlgprs

then, I connect by calling wvdial (with root privillege)

sudo wvdial

Just be very cautious with the cost as it is charged per KB!
Enjoy...

Let's Celebrate a Good Time

Celebration Lyrics

Installing ZABBIX 1.4.1

The new ZABBIX is getting better and better. Below are the steps I did to get
ZABBIX 1.4.1 up and running. (Assumed there is already Apache2, PHP and MySQL running)

1. First, get the source code.
$ wget

http://optusnet.dl.sourceforge.net/sourceforge/zabbix/zabbix-1.4.1.tar.gz

2. Extract the source code
$ tar -xvvzf zabbix-1.4.1.tar.gz

3. Prepare MySQL. by creating database for ZABBIX
$ mysql -u<username> -p<password>
mysql> create database zabbix;
mysql> grant all on zabbix.* to <username>@localhost identified
by '<mysqlpassword>';
mysql> quit;
$ cd <path-of-your-zabbix-source>/create/schema/
$ cat mysql.sql | mysql -u<username> -p<password> zabbix
$ cd ../data
$ cat data.sql | mysql -u<username> -p<password> zabbix
$ cat images_mysql.sql | mysql -u<username> -p<password> zabbix
$ cd ../..

4. Configure the source code, then proceed with install
$ ./configure --enable-server --enable-agent --with-mysql --with-net-snmp --with-libcurl
$ sudo make install

5. Create zabbix config files
$ sudo mkdir /etc/zabbix/
$ sudo cp
<path-of-your-zabbix-source>/misc/conf/zabbix_server.conf /etc/zabbix/
$ sudo nano /etc/zabbix/zabbix_server.conf

6. Create directories for the frontends
$ sudo mkdir /usr/local/zabbix
$ sudo chown -R <username.username> /usr/local/zabbix/
$ rsync -rvu <path-of-your-zabbix-source>/frontend/php /usr/local/zabbix/

7. Edit Apache2 config file to point your own ZABBIX url into the frontend's
path

8. Open a web browser, go to your ZABBIX url, then proceeds from there

9. To get ZABBIX up, you need to execute zabbix_server.

Done :-)

I Love You

I Love You Lyrics

2007

Selamat Tahun Baru 2007

Bimbo - Semalam di Malaysia

aku pulang
dari rantau
bertahun-tahun di
negeri orang
oh, Malaysia

oh, dimana
kawan dulu, kawan dulu
yang sama berjuang
oh, Malaysia

kekasih hatipun
telah pula hilang
hilang tiada pesan
aduhai nasib
apakah daya
cita hampa
jiwaku merana
mana dinda

inilah kisahku
semalam di Malaysia
diri rasa sunyi
aduhai nasib
apakah daya
aku hanya
seorang pengembara
yang hina

It works!!!

One thing I just realized after upgrading to Edgy, all hotkey in my desknote, which by the way is an ECS A907, works out of the box. No hacking, no tweaking, no user intervention. The volume manager key works, the "internet" key fires up Firefox and the "mail" key opens Evolution.

Now...if only I could make use of that f***in' flyin' windows key ...

Edgy upgrade fail on acpid

I just upgraded my dapper into edgy. everything went fine but acpid and
everything that depends on it.
After several hours of googling... I found the answer from launchpad.
The workaround are:
1. Shutdown the acpid (I removed it instead)
2. sudo killall hald
3. sudo dpkg --configure -a
4. sudo apt-get install acpid

Perhaps 4 months is a bit too short for a release cycle of a distro as
massive as Ubuntu...

Mounting Remote Directories using SSHFS

Due to limited harddisk capacity, I stored my edgy repository in an external USB hard drive.
To access it, I mount it using sshfs. Here is how I did it in Ubuntu 6.06.

$ sudo apt-get install sshfs

$ sudo modprobe fuse

$ mkdir /somewhere/localfolder/

$ sshfs -o allow_other user@remotehost:/somewhere/somefolder /somewhere/localfolder

To unmount it just use the normal umount command

$ sudo umount /somewher/localfolder

Now I have edgy repo, shall I start upgrading now... ?
I heard some bad rumors about upgrading dapper to edgy.
I think I need to do some backup first.

screen bash

When executing application using screen, I found that if the application went bad, we couldn't find out the error unless we specificy to log it. My debmirror script sometimes fail and I don't know if it is fail unless I repeat the script again.

Hence, bash must go first :-)

It's also quite handy to hide whatever I am doing on the screen as I only need to press C-a d to detach it.

Lust : Feature or Bug

Q: What is lust, a feature or a bug?
If it is a bug, then we are still in development stage and shouldn't have been released yet.
If it is a feature, then why some of us must go to hell because of it?

A: Well, probably deep inside our heart, there are lots of things that was meant to be patched by ourselves.

Hmm... a self-repairing apps...
Thank God we're not running Vista :p

pmount vs perl

After modifying debmirror, i copied it into a folder in my mounted portable hard drive.
The remaining space is quite large, so I put dapper & edgy as the target and start executing the script.
*bam*
myscript: /usr/bin/perl: bad interpreter: Permission denied

what the h###?!

I am absolutely sure I have no problem with permissions as the same script also copied into the parent directory of
a running ubuntu local ftp repository, and it works.

After checking every possible permission problem I encountered, I finally came into mount permission.
I mounted the portable hd using pmount (it's a usb-connected external hd) and it turnout that the default parameter
used by pmount include a noexec option, therefore, when I mounted it using the classic mount, the script worked.

Now, one question remain...
How come a perl script is considered a binary executable, while bash script is not?
Hmm...

Blogging via mutt

In blogspot, one can post his/her blog via mail. I like this feature because of two reasons :
1. The built in blogspot editor is terribly *cough*bloated*cough* slow
2. Due to aging hardware, opening firefox in my laptop takes zillion years
The problem is, the reason #2 is also the reason why I hate opening evolution in my laptop.

Few days ago, I installed mutt. The setup is not perfect yet, but I found myself quite enjoying it.
It loads extremely fast... that I only keep evolution just for reading html-formatted-mail sent to me.
I can also deal with junk mails much better :-)

Patching debmirror...

I just realized that debmirror has a weakness in its design. Debmirror is designed to download the packages lists, selecting correct packages to be downloaded, then and only then,  download the packages. However, the packages selection, is somewhat long and tedious. Even worse, there is no progress indicator to tell us how much time left for package selection process to start downloading those damn packages.

I wonder if I can modify it to make it faster.

* searching google with keywords: perl tutorial*