How To Linux

Decent technical advice can be hard to find, found this site via twitter (follow me http://www.twitter.com/howtolinux).  

Well worth a read - http://www.ossramblings.com/

Edit /etc/sysconfig/iptables:

vi /etc/sysconfig/iptables

Add the following line

-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT

Save and restart iptables.

service iptables restart

You will need to update the repositories so you can get php 5.2

vi /etc/yum.repos.d/utterrambling.repo

Add

[utterramblings]

name=Jason’s Utter Ramblings Repo

baseurl=http://www.jasonlitka.com/media/EL5/i386/

enabled=1

gpgcheck=1

gpgkey=http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

Change the baseurl to http://www.jasonlitka.com/media/EL5/x86_64 if 64 bit.

Install the necessary packages

yum install mysql-server httpd php php-mbstring gd php-gd php-mysql

Get Elgg

wget http://elgg.org/getelgg.php?forward=elgg1.5.tar.gz

untar it

tar xvfz elgg1.5.tar.gz

put in /var/www/html

mv elgg1.5 /var/www/html

Change the permissions

chown -R apache.apache /var/www/html/elgg1.5/

Create the data folder

/var/www/data
chmod 777 /var/www/data

Create the database

mysql -u root
create database elgg;
exit

Goto /etc/httpd/conf/httpd.conf and edit it.

Find   <Directory “/var/www/html”> and then change

AllowOverride None

to

AllowOverride All

Goto http://yourserver/elgg1.5/ and install the ap.

Source of instructions – http://docs.elgg.org/wiki/Installation

I have tried quite a few different text editors, the one I prefer and can heartily recommend is a great free open source tool, notepad++ - http://notepad-plus.sourceforge.net/uk/site.htm

Here are the features of Notepad++ :

• Syntax Highlighting and Syntax Folding
• WYSIWYG
• User Defined Syntax Highlighting
• Auto-completion
• Multi-Document
• Multi-View
• Regular Expression Search/Replace supported
• Full Drag ‘N’ Drop supported
• Dynamic position of Views
• File Status Auto-detection
• Zoom in and zoom out
• Multi-Language environment supported
• Bookmark
• Brace and Indent guideline Highlighting
• Macro recording and playback

Zenoss is pretty straightforward to install and add devices but when you start wanting to extend the Zenoss Core and use it full capabilities it can be tough to get started.  I picked up the only Zenoss Admin book a few weeks ago and can heartly recommend it as a good primer to get you started with Zenoss.

View a sample chapter here - http://www.scribd.com/doc/5371809/Zenoss-Core-Network-and-System-Monitoring-Sample-Chapter

This is the book pitch from the Author;

This book will show you how to work with Zenoss and effectively adapt Zenoss for a System and Network monitoring.  Starting with the Zenoss basics, it requires no existing systems management knowledge, and whether or not you can recite MIB trees and OIDs from memory is irrelevant. Advanced users will be able to identify ways in which they can customize the system to do more, while less advanced users will appreciate the ease of use Zenoss provides.

The book contains step-by-step examples to demonstrate Zenoss Core’s capabilities. The best approach to using this book is to sit down with Zenoss and apply the examples found in these pages to your system.

Buy the book by clicking on the link below;

Twitter is a cool way to find great resources.  Shell fu is following me so I checked out their site, sounded good.  Great resource, lots of useful  and advanced shell scripts and command line tips.

Check it out at http://www.shell-fu.org/

Follow me on twitter at http://www.twitter.com/howtolinux

Follow shell-fu on twitter at http://twitter.com/shellfu

I am a huge fan of Zenoss, a great tool for monitoring your network and servers.  Zenoss Core is sufficient for basic monitoring but can be extended to all kinds functionality.

Zenoss delivers a single product to monitor the entire IT infrastructure:

• Networks – Routers, Switches, Firewalls, Access Points
   
• Servers – Microsoft Windows, Linux, Unix, HP, NetApp, Dell
   
• Virtualization – Complete VMware Virtual Infrastructure (VI3) Management, XenSource Monitoring
   
• Applications – Processes, Ports, Web Apps, Web Services, Databases, Middleware, Commercial Apps 
   

Zenoss released a maintenance release today, see the changelog.

Download it from - http://www.zenoss.com/download/links?nt

• Powerful Centralized Management enables full multi-node management for an unlimited number of servers and virtual machines; includes extensive graphical reporting and alerting, easy physical-to-virtual and virtual-to-virtual conversion tools, and a resilient, highly available management architecture with no single point of failure
   
• Live Motion and Multi-Server Resource Sharing incorporates powerful XenMotion™ technology that allows virtual machines to be moved from server to server without service interruption for zero downtime; also includes automatic balancing of compute power within a pool of physical servers, optimal virtual machine placement and multi-resource pool management
   
• Proven Hypervisor Engine powered by the 64-bit industry standard Xen open source hypervisor developed jointly by more than 50 leading technology vendors to take full advantage of the latest performance, security and scalability enhancements in next-generation servers, operating systems and microprocessors
   
• Fast Bare Metal Performance supports an unlimited number of servers and virtual machines with industry-leading consolidation ratios, near native performance on the most challenging application workloads, and virtually zero overhead in both Microsoft Windows® and Linux environments
   
• Easy Setup and Administration features familiar interface with easy wizard-driven configuration, intuitive Web 2.0 style search, and built-in auto-help that makes the learning curve for new administrators a snap
   
• Integrated Storage Management that supports any existing storage system, and includes built-in storage management features such as host-based logical volume management, snap shots and dynamic muti-pathing capabilities 
   

Check it out at - http://www.citrix.com/English/ps2/products/feature.asp?contentID=1686939

Puppet is an open-source next-generation server automation tool. It is composed of a declarative language for expressing system configuration, a client and server for distributing it, and a library for realizing the configuration.

Setup the EPEL repos for Centos – choose the correct package depending on  your installation.

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5Server/x86_64/epel-release-5-3.noarch.rpm

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm

Install puppet-server

yum install puppet-server

The 1.8.5 branch of Ruby shipped will RHEL5 can exhibit memory leaks. So install ruby 1.8.6++ (I did not on this server as it was  test not a production server).

Install the help docs

yum install ruby-rdoc

Create a manifest file at /etc/puppet/manifests/default.pp

vi /etc/puppet/manifests/default.pp

put this in it

# Create “/tmp/testfile” if it doesn’t exist.

class test_class {

    file { “/tmp/testfile”:

       ensure => present,

       mode   => 644,

       owner  => root,

       group  => root

    }

}

# tell puppet on which client to run the class

node pclient {

    include test_class

}

Start the puppet server

service puppetmaster start

Enable start on boot

chkconfig puppetmaster on

Now to install the Puppet Client on another server

Setup the EPEL repos for Centos – choose the correct package depending on  your installation.

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5Server/x86_64/epel-release-5-3.noarch.rpm

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm

Install puppet

yum install puppet

Setup puppet client to generate its own certificate request to the server

/etc/init.d/puppet once -v

Sign the certificate request on the puppet master server.  Use puppetca –list to see if any are available to sign.

puppetca –sign puppet01

Puppet01 must be the fully qualified domain name (FQDN) of you client server.

Run this on the client server again to retrieve the certificate

/etc/init.d/puppet once -v

Make the puppet start with the system

chkconfig puppet on

Make sure it is working on the client server.

puppet –test

You should see a dialog that creates the file /tmp/testfile

This is on a fresh install of Centos 5.2 64 bit.  Base install with no additional packages.  SELinux is disabled.

Download zenoss the full stack install (this is for 64bit)

mkdir ~/src

cd ~/src

wget http://nchc.dl.sourceforge.net/sourceforge/zenoss/zenoss-stack-2.3.2-linux-x64.bin

Change the permissions

chmod +x ./zenoss*.bin

Run the install

./zenoss*.bin

By default, the package is installed in the /usr/local/zenoss directory.  Enter a password for the root user of mysql.

Open ports on iptables

vi /etc/sysconfig/iptables

Add the following

#zenoss rules

-A RH-Firewall-1-INPUT -p tcp -m tcp –dport 8080 -j ACCEPT

-A RH-Firewall-1-INPUT -p udp -m udp –dport 514 -j ACCEPT

-A RH-Firewall-1-INPUT -p udp -m udp –dport 162 -j ACCEPT

#zenoss rules

Restart iptables.

service iptables restart

Login webadmin

http://<zenoss computer>:8080/

user – admin

password – zenoss

If you need to restart zenoss, use

service zenoss-stack restart