Onlyjoe

Reset Network Drivers to eth0…

joe — Wed, 16 May 2012 23:00:00 +0000

Recently I came across a issue, where a added a dual network card to my ubuntu server and instead of taking over the eth0 and continuing down the line in sequence. Ubuntu decided to just continue the sequence of eth1 and eth2. So it got me wondering why does it not take over the eth0, since the old network card is not there. It seems the culprit is the udev rules and the network cache which remembers the mac address of the previous card and leaves that eth0. So no other ethernet card can be eth0, till you delete the network cache and udev regenerates the device with the new network card. To resolve this issue you just need to delete the fie below and reboot.

# rm -f /etc/udev/rules.d/70-persistent-net.rules

Install Squid in 600 seconds…

joe — Wed, 16 May 2012 01:48:20 +0000

Currently I have a few firewall issues and while I am trying to resolve those issues. I decided I still needed to surf the internet. Till I can resolve my firewall issues, my option was to either surf with my mobile 3g unit, do my internet surfing only at work, or none at all. My other option was to install squid, as a bandaid issue.

The steps to get squid working is shown below.

# apt-add install squid3

We need to edit the squid configuration, before we can start the application.

# cd /etc/squid3
# cp squid.conf squid.conf.orig
# vi squid.conf

We now modify the squid configuration file, and modify, add the following into the squid.conf

acl our_networks src 192.168.0.0/24
acl localnet src 127.0.0.1/255.255.255.255
http_access allow our_networks
http_access allow localnet

An optional extra is if you want to modify the cache of squid the line that needs to be modified is

cache_dir ufs /var/spool/squid3 7000 16 256

The only part you may wish to modify is the 7000 which denotes the amount of megabytes. You can increase or decrease the size of your cache, depending on your needs.
Before you start squid you need to create the cache, with the following command.

# squid -z

You now can start squid with the command

# /etc/init.d/squid restart

Install Nagios in 600 seconds…

joe — Tue, 10 Apr 2012 23:00:46 +0000

Recently I installed Nagios from the Ubuntu 10.04 repositories and found that the repository version is a version behind the current behind. I decided to install Nagios from source code directly. It is a simple process, below is how it is installed. Note there are two parts to Nagios, the core application and the plugins.

Nagios Core:

We need to install dependancies before we install nagios.

# apt-add install build-essential php5-gd wget libgd2-xpm libgd2-xpm-dev

We now need to create the nagios user on the system, for the nagios software to run under.

# adduser –system –no-create-home –disabled-login –group nagios

# groupadd nagcmd

# usermod -G nagcmd nagios usermod -a -G nagcmd www-data

Now that we have create the nagios user for the system, we need to download the nagios software.

# cd /usr/src

# wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.3.1.tar.gz

# wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.15.tar.gz

Now we build the Nagios software

# tar -xzvf /opt/nagios-3.3.1.tar.gz cd /opt/nagios-3.2.3 ./configure –with-command-group=nagcmd

# cd nagios-3.3.1

# ./configure –with-command-group=nagcmd

We now compile the software and install it, upon the system.

# make all

# make install

# make install-init

# make install-config

# make install-commandmode

Configure the Nagios core.

# vi /usr/local/nagios/etc/objects/contacts.cfg

You need to edit the alias and email lines.

# cd /usr/src/nagios-3.3.1

We need to install the web based frontend software.

# make install-webconf

We need to create the login name of the user from the apache frontend. You wil also need to enter a password for the nagiosadmin user.

# htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

We need to reload the apache2 configuration.

# /etc/init.d/apache2 reload

Nagios Plugin:
We now need to build the plugins from source. Below are the steps below.

# cd /usr/src

# tar xzf nagios-plugins-1.4.15.tar.gz

# cd nagios-plugins-1.4.15.tar.gz

# ./configure –with-nagios-user=nagios –with-nagios-group=nagios

# make

# make install

Now we get Nagios running. We need to get the permissions corrected so the startup files work.

# chmod +x /etc/init.d/nagios

# /usr/sbin/update-rc.d -f nagios defaults

We need to check that our nagios configuration is good, or Nagios will not start. The configuration check will show us if there are any errors in the configuration file.

# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

If no errors are shown, you are able to start Nagios now.

# /etc/init.d/nagios start

You will be able to access Nagios from a web browser. The address will be http://localhost/nagios or http:///nagios Remember when you created the Nagios admin user above, you need to remember

Mail Alerts

If you want Nagios to email you on alerts, when things go wrong. You need to install

#apt-get install mailutils sendmail

Select your mail server as a internet site. Note that you can modify the nagios /usr/local/nagios/etc/objects/commands.cfg file or easier process is to link /usr/bin/mail to /bin/mail. You do not need to restart nagios if you just done the soft link of the mail files.

Install Plone under Ubuntu…

joe — Tue, 10 Apr 2012 02:04:28 +0000

I have been looking for a good cms/wiki to document the changes at my work. I tried mediawiki and got fustrated by the weird markup language, to create a textbox. I tried moinmoin and found security was a issue. So now I have decided to try Plone. I thought Plone looks good. But there are no Ubuntu packages and I need to install the software from source.

Before you can install Plone from source you need to install some pre-requisite Ubuntu packages.

# apt-get install build-essential libssl-dev libxml2-dev libbz2-dev libjpeg62-dev libreadline5-dev wv poppler-utils

You need to get the Plone software to your server so you can install.

# cd /usr/src

# wget https://launchpad.net/plone/4.1/4.1.4/+download/Plone-4.1.4-UnifiedInstaller.tgz

# gzip -d Plone-4.1.4-UnifiedInstaller.tgz

# tar -xvf Plone-4.1.4-UnifiedInstaller.tar

# cd Plone-4.1.4-UnifiedInstaller

Now we can install Plone..

#./install.sh standalone

The standalone option for means it will only be installed on the server, and be a self contained cms. Once this is done you need to start Plone.

#cd /usr/local/Plone/zinstance

#./plonectl start

You can now acces the Plone cms from the address from http://localhost:8080 or http://:8080.
Enjoy.

Java for Ubuntu…

joe — Fri, 30 Mar 2012 06:59:47 +0000

Recently I needed to install Oracles java, and not the open source java for android development. Oracle do not allow Conical to distribute java with Ubuntu distributions. So you need to add the Oracle repositories after your Ubuntu installation. below shown is a example of how it done.

You need to add the Oracle repository to your Ubuntu installation.

# apt-add-repository pap:flexiondotorg/java

You now need to update your repository database.

# apt-get update

Now you can add the Oracle Java repositories.

# apt-get install sun-java6-jre sun-java6-jdk sun-java6-plugin

Thats all its done.

Mac Wyse 60 Terminal Emulation…

joe — Tue, 06 Mar 2012 20:00:21 +0000

Recently I have had to go back to Wyse 60 terminal emulation. I needed Wyse 60 terminal emulation due to legacy applications that have no other option but to be accessed. I could spend a fair few dollars on a commercial Wyse 60 terminal emulator. But in the spirit of free and open source, there is a free Wyse 60 terminal emulator out there for use.

You can download the Wyse 60 source from the following site.

http://code.google.com/p/wy60/

You can also directly download the source code from…

http://code.google.com/p/wy60/downloads/detail?name=wy60-2.0.9.tar.gz&can=2&q=

Once you have the source code downloaded, you can upack the source code.

# tar -xvfz wy60-2.0.9.tar.gz

Now we can compile the source code and install the executable.

# cd wy60-2.0.9
# ./configure
# make
# make install

Once you have compiled an installed the code. To activate the Wyse 60 emulation you type.

# wy60

Once this is run, you screen is now in Wyse 60 emulation, and you are able to ssh etc like any other screen, but in Wyse 60 emulation.
Or Under Ubuntu 10.04, you can just add this as a package.

Ubuntu 10.04

# apt-get install wy60

This is simpler than compiling the code.

Setup a PPTP server:

joe — Mon, 05 Mar 2012 20:00:37 +0000

Recently I have been wanting to connect to my home network, from anywhere in the world. I want to connect back home via the device I have in my hands on me at the time. This could be my osx, windows 7, linux laptop, ipad, iphone or android device. I was originally thinking of setting up openvpn, as this was the easiest to setup, but decided against as there is clients for windows, android, linux, osx but not for ios devices. So I had to look for another virtual private network software. I was looking of setting up a ipsec/l2tp server, but decided at the moment against this, as it will take some time to setup and debug. This left me with pptp. This protocol is common to all devices and needed no extra client installed for it to run.

The following steps below will show you howto setup a pptp server.

Ubuntu 10.04

# apt-get install ppp pptpd pptp-linux

Enable port 22 in your firewall to pass throu for emergency purposes to ssh back into the machine. Here is the command to allow ssh through. You need to edit your permanent firewalls for this work on reboot.

# /sbin/iptables -A INPUT –protocol tcp –dport 22 -j ACCEPT

Enable port 1723 in your firewall to pass throu for pptp protocol to work on your system.

# /sbin/iptables -A INPUT –protocol tcp –dport 1723 -j ACCEPT
# /sbin/iptables -A INPUT –protocol udp –dport 1723 -j ACCEPT

now we modify the /etc/pptpd.conf file. Look for the lines below in your file and modify them. These lines represent the ip address the vpn connections can have upon your local network.

localip 192.168.0.1 remoteip 192.168.0.241-255

The localip is the ip if the internal nic behind the wan port. This ip address is the ip of the pptp server. The remoteip is the ip’s allocated by the pptp process when you make a connection. I have allocated 15 ip’s. This allows me to have 15 devices connected to the server. I probably only need two ips allocated.

Now we modify /etc/ppp/pptpd.options edit the ms-dns entries to reflect the domain nameserver your network uses. A example is below. ms-dns 8.8.8.8 ms-dns 8.8.4.4

ms-dns 8.8.8.8
ms-dns 8.8.4.4

Also modify your file /etc/sysctl.conf

net.ipv4.ip_forward=1

No we need to restart the system controls. The other option than below is restarting the machine.

# sysctl -p

You now need to add users to the system, so we can make a login into the pptp server. You modify the /etc/ppp/chap-secrets file.

username * user-password *

You now need to restart the pptpd daemon for all the changes to be implemented.

# /etc/init.d/pptpd restart

Create a VirtualBox Headless Machine…

joe — Mon, 05 Mar 2012 01:39:30 +0000

More and more I have been running Virtualbox virtual servers upon my main Ubuntu 10.04 server. I used to create the virtual server upon my Macbook Pro 13″, then export the image, and reimport the image upon the linux headless server. Recently I found it was much easier to create the VirtualBox server upon a headless linux server. Certainly creating the virtual server upon a guy based tool is a lot easier, but it does not save time when you need to export and import the image across to the linux server.

The following steps below will show you howto setup a VirtualBox virtual headless server.

Ubuntu 10.04.03

We now create and register the virtual server with the command VBoxManage.

# VBoxManage createvm -name “server” –ostype Ubuntu_64 –register

We allocated the amount of memory the virtual server will have, the sequence of boot, e.g. dvd first, and which either net adapter does the virtual machine attach itself too. The memory we have allocated is 1024mb and the ethernet it uses is eth4.

# VBoxManage modifyvm “server” –memory 1024 –acpi on –boot1 dvd –nic1 bridged –bridge adapter1 eth4

We now create the hard disk or virtual disk for the virtual server. We allocated 100gb of hard disk space, and store the virtual hard disk file in /home/vbox

# VBoxManage createvdi –filename “/home/vbox/server.vdi” –size 100000

We state that the virtual server uses a ide controller. We can use ahci also, but ide is safe to use.

# VBoxManage storagectl “server” –name “IDE Controller” –add ide

We state that the virtual server uses the ide controller and attach the vital server hard disk to the ide controller.

# VBoxManage storageattach “server” –storagectl “IDE Controller” –port 0 –device 0 –type hdd –medium “/home/vbox/server.vdi”

We need also attach the dvd driver to the ide storage controller. Also we attach the iso image to the dvd drive, so that when we boot the virtual server for the first time, it boots the virtual dvd driver and uses the iso image.

# VBoxManage storageattach “server” –storagectl “IDE Controller” –port 1 –device 0 –type dvddrive –medium “/home/vbox/ubuntu-10.04.3-server-amd64.iso”

We now allow remote desktop software to connect to the virtual server.

# VBoxManage modifyvm “server” –vrde on”

We now set the port, we can connect to the virtual server on with the remote desktop software. We can connect to the virtual server on port 3392. You can use Microsoft Remote Desktop Connection to connect.

# VBoxManage modifyvm “server” –vrdeport 3392

Once this is all done we can now startup the headless virtual server.

# VBoxHeadless –startvm “server” &

You can shutdown the virtual server with the following command.

# VBoxManage controlvm “server” poweroff

You can pause and restart the virtual server, but within the means of this document, I will not explain them, as they are commands not really needed.

Fujitsu P1620 a new hope…

joe — Sun, 23 Oct 2011 22:00:38 +0000

I have had for a while a Fujitsu P1620 small form factor convertable. I have had for a while Windows Seven working upon the machine, but with only two gigabytes of ram, performance was limited at best. I have decided to install ubuntu 11.04, 64 bit desktop, and remove the gnome desktop for the xfce desktop. The other issue is the very slow 4200rpm 100gb hard disk. The installation was about sixty minutes to install. Half of the installation was downloading packages from the ubuntu repository. I used a external usb dvd rom drive to install ubuntu 11.04, 64 bit desktop. I will further along the way try to document the configuration of software and hardware as in the touchscreen which seems a tricky issue.

Converting RHEL to CentOS:

joe — Wed, 19 Oct 2011 22:00:32 +0000

One of the biggest issues when running RedHat Linux in any verison is how to get updates when you do not pay for mantenance. As far as I know, you cannot get the updates from redhat for free once your 30 day trail is over. Many companies need to run redhat due to the applications we designed around redhat in linux. There are many ways to get around this when running different flavours of linux, but they necessary become a pain in the backside when it comes to this, as the next update of the flavour may break the application. A workaround is too use the free version of redhat enterprise linux which is CentOS. You can convert a redhat machine to CentOS, very easily. Below will show you the process of how it is done.

CentOS 5:

# yum clean all

# mkdir ~/centos

# cd ~/centos/

# wget http://mirror.centos.org/centos/5/os/i386/RPM-GPG-KEY-CentOS-5

# wget http://mirror.centos.org/centos/5/os/i386/CentOS/centos-release-5-8.el5.centos.i386.rpm

# wget http://mirror.centos.org/centos/5.7/os/i386/CentOS/centos-release-notes-5.8-0.i386.rpm

# wget http://mirror.centos.org/centos/5/os/i386/CentOS/yum-3.2.22-39.el5.centos.noarch.rpm

# wget http://mirror.centos.org/centos/5/os/i386/CentOS/yum-updatesd-0.9-2.el5.noarch.rpm

# wget http://mirror.centos.org/centos/5/os/i386/CentOS/yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm

# rpm –import RPM-GPG-KEY-CentOS-5

# rpm -e –nodeps redhat-release

# rpm -e yum-rhn-plugin

# rpm -Uvh –force *.rpm

# yum upgrade

At the time of this post CentOS 5.7 is the highest release to upgrade a redhat enterprise 5 installation. I am yet to work out howto upgrade a redhat enterprise 6 release to CentOS 6.

update 2012.04.04