Tech Chorus

Redmine is a software project management tool which has Wiki, issue tracer, source code browser and other cool features built in. If you want to install Redmine with MySQL and Nginx on CentOS 6, follow these steps.

I always use EPEL repository with CentOS. EPEL provides additional RPM packages. We can use Nginx and some Ruby gem packages from EPEL.

Enable EPEL:

rpm -Uvh http://download.fedora.redhat.com/pub/epel/6/i386/epel-release-6-5.noarch.rpm

Install required packages:

yum install nginx mysql-server ruby rubygem-rack rubygem-rake ruby-mysql

Redmine requires a Ruby gem called i18n. I couldn't find the RPM for i18n gem. I had to install i18n gem using the gem installer.

gem install -v=0.4.2 i18n

Start MySQL server:

/etc/init.d/mysqld start

Use the MySQL secure installation program:

mysql_secure_installation

Connect to the MySQL server as root:

mysql -u root -p

Create a MySQL database and user for Redmine:
mysql> CREATE DATABASE redmine character set utf8;
mysql> GRANT ALL PRIVILEGES ON redmine.* TO 'redmine'@'localhost' IDENTIFIED BY 'secret_password' WITH GRANT OPTION;

Amazon Simple Storage Service or Amazon S3 is a storage service with a web API. I use Amazon S3 to store backups of my blog and other sites. I made a simple python script to handle file uploads to S3.

In order to use Amazon S3, first create a bucket using your Amazon AWS account. As the name suggests, bucket is a container. You can create buckets using the AWS management console.

The script we're going to write will take two input parameters

1. Path to file, local
2. Target S3 path

Title: Learning Nagios 3.0
Publisher: Packt Publishing
Author: Wojciech Kocjan
ISBN-10: 1847195180
ISBN-13: 978-1847195180

Nagios is a powerful and popular network monitoring software. I contacted PackT and asked for a review copy of the book.

Read the full table of contents on the publisher's site.

The topic being system administration, I could read the book from cover to cover in three days.

Like many other technical books, introductory pages of Learning Nagios 3.0 sells you Nagios. The first chapter convinces you why you should use Nagios to make your life easier by setting up automated monitoring of your servers.

Nagios is a popular networking monitoring software. Nagios lets you monitor your IT infrastructure, be it servers, routers, switches or other devices. In this post, I will walk you through the steps of installing and configuring a basic setup of Nagios on CentOS.

At the end of the tutorial you will be have a working Nagios setup to monitor

• local disk space usage
• local system load
• an external website

Whenever there is a problem or recovery with any of the above, Nagios will alert you via email.

Unless you have a strong reason to compile Nagios yourself, you should use the binary packages available for your Linux distribution.

RPMForge provides packages that are not included in CentOS repositories. We will use the Nagios packages from RPMForge.

Enabling RPMForge repository

For 32 bit machines use these commands:

wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.i386.rpm
rpm -ivh rpmforge-release-0.5.1-1.el5.rf.i386.rpm

For 64 bit machines use these commands:

wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm
rpm -ivh rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm

Installing And Configuring Nagios

The topic was Free Software Movement and GNU/Linux operating system.

It was a long drive to Reva Institute, 40 kilometers from home. I reached the venue in time thanks to the moderate traffic. The third floor was already filled. I had to go to the fourth floor to listen to the speech. The auditorium stage can be viewed from both third and fourth floor. The floor had two elevated blocks, one above the other. There were no chairs on the fourth floor. The floor was a bit dusty. Approximately five hundred people attended the event.

The talk was usual as you would expect. RMS started off, explaining the meaning of free software. The four freedoms. Then he talked about the history of the free software movement, FSF, GNU, Linux, Emacs. Even though I am quite familiar with the topics, it was interesting to hear them from the horse's mouth.

Moving around

You can use the arrow keys on keyboard to move around in the command line. Bash also provides convenient keyboard short cuts to navigate effectively. Try them out and see for yourself.

To become a Bash pro user you have to get yourself familiar with the keyboard shortcuts. Once you do, you'll find yourself productive.

Moving around words using ESC+f and ESC+b are my favourites in this list. Jumping to first and last lines of the history list is also useful.

Broadcom provides Linux drivers for most of its wireless chipsets. Prior to the release of official drivers from Broadcom, the open source software community had various workarounds. Some people used Windows drivers through ndiswrapper. Others used fwcutter.

The RPM Fusion Repository for Fedora offers the Broadcom wireless drivers from its repositories. You can install them using yum.

Step 1: Enable the RPM Fusion repositories

 
rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm

How to play music and video(MP3, MPEG, AVI, FLV and other multimedia files) in Fedora 12?

Due to patent encumbrance codecs required to play some proprietary file formats are not shipped with Fedora. Codecs are the programs that encode and decode digital data. These codecs are available in the rpmfusion repository for Fedora. You will be able to play mpeg, mp3, avi, flv and other commonly used file formats for music and video. You will require an Internet connection to download and install these packages on your computer.

Let us get started. Are you ready?

How to configure keyboard short cut to minimze all windows on KDE 4.3.3 on Fedora

Having the Show Desktop button on the panel is something everyone would want. If you are unable to find the settings follow the instructions below.

1. Install the kdeplasma-addons package.

# yum install kdeplasma-addons -y

2. Add the Show Desktop widget to the panel.

• Click the Cashew button on the panel - the rightmost corner button
• Click Add Widgets
• Click Show Desktop
• Click Add Widget

MySQL has a query logging feature. In order to use it you have to first enable it.

Enabling the general query log

Step 1: Set your log file in /etc/my.cnf

vi /etc/my.cnf

In the [mysqld] section specify the general log file name:

log=/var/log/mysqld.general.log

Step 2: Create the file and make sure it is owned by the system user mysql

touch /var/log/mysqld.general.log
chown mysql.mysql /var/log/mysqld.general.lo