Category: Scripting

Reviewing boot logs on Debian

Recently, I installed a debian system as a server from the netinst CD. From the debian website:

A network install or netinst CD is a single CD which enables you to install the entire operating system. This single CD contains just the minimal amount of software to start the installation and fetch the remaining packages over the Internet.

The install was straight forward and i only opted to install standard utilities and nothing else. Everything installed successfully and the system booted without a single problem.
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Using EncFS for safefly storing data

Just wanted to share what i think is a nice solution to encrypting your data. If you have confidential data that you would like to store securely, then have a look at EncFS. According to the man page, EncFS creates a virtual file system which stores encrypted data in one directory (they call this directory the rootdir) and makes it available unencrypted in another directory (mountPoint). The user must supply a password that would be used to encrypt the user’s files and file names. EncFs relies on the underlying file system. Therefore if there are any limitations on the underlying file system, they will be inherited by EncFS.

One of the blogs that i follow (HowtoForge.com)has a nice write-up on using EncFS that I encourage you to check out. Below, I will provide a summary of the key commands that you will need to get up and running. Read more

PingTunnel

monitor

Tunnel your tcp traffic through ICMP echo/ reply packets or UDP 53(DNS) packets

So you are at a local coffee shop with your laptop and see an open access point that you want to connect to. You connect to the AP and open up your favorite webrowser, only to find that you are presented with a page that asks for a code for you to proceed with your internet cravings. WTF !! Many places such as coffee shops provide you with wireless internet connectiviy at a small cost (usually more than the coffee you purchased). You recieve a code when you purchase the coupon for wireless access and then you go onto your webrowser, enter that in and the you’re good to go. Well for almost everything digital, there is most likely a walkaround to do things and in this case there is. Enter the world of protocol tunneling. The basic idea behind this is to transfer data from one protocol or port number, using another protocol (or port number). Read more

Helpful log parsing tips

tux_awk1Most programs and services produce logs. When a user visits an apache web server, the service will most likely keep a log of that request, along with the date and requester’s ip address. Other details might be logged as well. Here us an example of some entries in a logfile:

192.168.1.20 - - [21/Sep/2011:11:04:40 +1000] "GET / HTTP/1.0" 200 468
192.168.1.20 - - [21/Sep/2011:11:07:48 +1000] "GET /login.php HTTP/1.0" 200 6433

Log files would usually contain hundreds of such entries, most, if not all of which are important to us. If there is an issue with a service, perhaps there is an entry in the logfile that can tell us why. Another scenario is where management require some statistical information. For example, how many unique IP addresses visited their website in the past hour and what pages did they visit. Or which web pages are the most frequently visited. Read more