Linux server Monitoring with Nodequery

One of the best way  to which i think bloggers can monitor traffic on their website is by using Nodequery. Though it is well adapted for huge businesses, i am sure you would like to adventure on this Public API. NodeQuery is currently in public beta and completely free of charge.

Photo Credits to Nodequery.com

To install NodeQuery, you will need to register on the official website. You will be prompted to install the Agent on your machine by downloading it from Github using the command https://raw.github.com/nodequery/nq-agent/master/nq-install.sh

After installation you need to launch the bash script and immediately after less than 3 minutes you server is being monitored.

For the free version, you have the possibilities to have a full overview of your system, Network Usage, Network latency, Average Load, Ram and Swap Usage, Disk Usage and the Top Processes.

Well, there are several more features to explore.

Cool isn’t it ?


The WTF Star!

If you are thinking about the acronym “WTF” as usual in a chat conversation, then you are WRONG!.. 🙂 Located in the exoplanetary system, the WTF star – “Where’s the Flux” also known as KIC 8462852 or simply Tabby’s star is a strange star as a potential evidence of an ancient alien megastructure situated above the milky way between the Cygnus and Lyra constellations.

Screenshot from 2015-10-25 17:43:22
Screenshot taken from my Stellarium indicating the location of Cygnus and Lyra

Thanks to the Kepler Project, Kepler, a space telescope is searching for exoplanets orbiting other stars in our galaxy. “NASA wants to find out if there is life beyond our solar system so kepler is looking for planets like earth incise that could be potentially habitable”  – Natalie Batalha, research astronomer at NASA Ames Research center.

kepler_0
Kepler Space Telescope – Photo credits to NASA – nasa.gov

Have astronomers found alien life in space ? This is indeed the most challenging mission to mankind after the discoveries made by the Kepler Project. “We are clueless as to what could cast the shadow bigger than Jupiter.. Is it a comet? Is it an asteroid? Is it a media? and one by one we ruled out all the logical possibilities. That last possibility is that it is artificial. It could be a Dyson Sphere. A Dyson sphere is built by civilization that can play with stars that envelop the entire star with a shell absorbing all the star light “Dr Michio Kaku, Theoretical Physicist.

Indeed, a good job of the Kepler Space exploration team. Of course if this is going to be a remarkable claim, a remarkable proof of the century is waiting us ahead. 


HTTP 2.0 & Web development – LUGM Meetup

The Linux User Group of Mauritius – LUGM carried out a meetup on Saturday the 24th of October 2015 at the University of Mauritius on HTTP 2.0 and Web Development by Loganaden Velvindron on HTTP 2.0 & Web Development. Based on SPDY – “just say speedy”, the HTTP 2.0 was developed by the IETF – Internet Engineering Task Force, to improve user experience, latencies, CDN and various technologies. Logan, start with  the presentation on the shortcomings of HTTP 1.1 and lead the audience to a better understanding of the evolution of HTTP 2.0

I do not own copyright to this picture - All rights reserved to Akamai.com
I do not own copyright to this picture – All righ reserved to Akamai.com

You can view the Video here:

The following points were briefly elaborated:

  • Shortcomings of HTTP 1.1
  • HTTP 2.0 Client support
  • HTTP 2.0 Server side
  • SPDY Highlights
  • Binary Framing
  • Multiplexing
  • Stream Priorities
  • Header Compression
  • Server Push technology and a demo using NodeJS


Move your /home to a new LVM partition

To have better control and security over your Linux OS, you might want to move your say /home  or /var to another LVM partition. The advantage is that you can easily increase / decrease the size at a future stage.

On this article, i will take an example of the /home directory and we will move it to a fresh disk on Virtual Box. Here is an example of a df -h on my virtual Machine.

We will now add a new disk [sdc] by creating another VG.

Screenshot from 2015-10-21 19:22:05

Start with the following steps:

  • pvcreate /dev/sdc
  • vgcreate vghome /dev/sdc
  • lvcreate -l 100%FREE vghome
  • lvrename /dev/vghome/lvol0 /dev/vghome/lvhome 

Screenshot from 2015-10-21 19:27:38

Once you have succesfully created the lvhome, you will need to edit your /etc/fstab before mounting the partition so that each time you reboot your machine, it will render the same configuration.

 

I have inserted the following parameters:

  • /dev/mapper/vghome-lvhome /home ext4 defaults,noatime 1 2 

Screenshot from 2015-10-21 19:32:28

 

You will also need to format the partition before mounting the disk with this command :

  • mkfs.ext4 /dev/mapper/vghome-lvhome
Screenshot from 2015-10-21 19:35:49
  • You now need to mount the partition by using the following command mount /home
  • Here is now the results from a df -h
Screenshot from 2015-10-21 19:39:55
Tips:
  • You can also format your partition with ext3 when your /etc/fstab has been specified with the ext4 format as ext4 support ext3
  • You can also specify the name of the lv directly whilst creating it by using the command lvcreate -l 100%FREE -n lvhome vghome so that you don’t need to rename anew the lv. By default on Vbox and Vmware it use lvol0
  • More articles i have posted on LVM are :

Add and extend disk on Virtual Box through LVM

Managing LVM with Pvmove – Part 1

Managing LVM with Pvmove – Part 2


ZeNmap – The classic way of Nmap

Nmap is a free and open source utility for network exploration and security auditing whilst ZeNmap is a multi-platform graphical Nmap frontend and results viewer. It was originally derived from Umit which was created as part of the Nmap/Google Summer of Code program. ZeNmap is compatible with almost all types of Operating system. I have tested ZeNmap on Ubuntu and FreeBSD and it works pretty fine.

Some basic ‘nmapping’ funs from my Kali Linux Box

Look for visible IP in your network –  nmap -sP 192.168.1.0/24

Check number of ports opened – nmap -Ss 192.168.1.0/24

Find the operating systems being used in the same network – nmap -O 192.168.1.0/24

You can even check the ACK bit during the TCP handshake authentication – nmap -sA 192.168.1.0/24

Screenshot from 2015-10-19 19:02:35
Tested with instances of several OS running on Vbox

Of course the world of Nmap is so vast that you will need to go through the Manual to design your own way of exploring the Nmap command. There are many features and capabilities such as Hosts identification, Port scanning, Interrogation of network services, OS detection etc.. How does Nmap works? Since every hosts or deivces is connected to a network and has some network ports open and is consequently waiting for connections, the Nmap tool initiate connection to the 1000 most used ports whether it is open responding to an incoming connection, closed and has no service running but can respond to probes, filtered; i.e protected by a Firewall, unfiltered; post can be accessed but no chance to determine if its opened or not and the last one is the open / close filtered.

What is more interesting is the ZeNmap tool where you can scan network using GUI. At this level, parameters are defined like Paranoid, Sneaky, Polite, Normal, Agressive and Insane.

Screenshot from 2015-10-17 11:37:21
A paranoid scan performed here

 ZeNmap can also be used for firewall evasion techniques, source address and port spoofing, setting flag values on both IP and transport level. Results are also shown through a Map.

Screenshot from 2015-10-20 05:54:29