Yesterday while re-purposing a server I was removing packages with apt-get and stumbled upon an interesting problem. After I removed the package and all of it's configurations, the subsequent installation did not re-deploy the configuration files.
After a bit of digging I found out that there are two methods for removing packages with apt-get. One of those method should be used if you want to remove binaries, and the other should be used if you want to remove both binaries and configuration files....
If you haven't seen it yet there is a new troubleshooting tool out called sysdig. It's been touted as strace meets tcpdump and well, it seems like it is living up to the hype. I would actually rather compare sysdig to SystemTap meets tcpdump, as it has the command line syntax of tcpdump but the power of SystemTap.
In this article I am going to cover some basic and cool examples for sysdig, for a more complete list you can look over the sysdig wiki....
One of my biggest pet peeves as a Linux sysadmin is when I see users, or even other sysadmins using kill -9 on the first attempt to terminate a process. The reason this bugs me so much is because it shows either a lack of understanding of the kill command or just plain laziness. Rather than going on a long rant about why this is bad, I wanted to write an article about the kill command and how signal works in Linux....
Lately if you have been paying attention to tech or even mainstream media you might have seen a few stories about data breaches. Sometimes these data breaches have allowed attackers to gather unencrypted passwords or credit card numbers. In the past these types of attacks still happened, but there was not as many attacks as today and when they happened they were kept secret. With more and more internet based services becoming part of peoples lives, there is even more targets for attackers who are looking to get sensitive data....
Ever run a shell script and get the following error?
# ./dosfile.sh : bad interpreter: No such file or directory The error may look like there is a problem with your scripts SHEBANG where you specify the interpreter, so you go look and the line contains #!/bin/bash which is correct. So then you start wondering if there is a problem with the /bin/bash binary, and all sorts of thoughts of what would happen if /bin/bash was missing or broken start racing through your head....