Monitoring the Apache web server with Cfengine 3

During the last weeks I received a lot of positive feedback on my blog posts and the Cfengine 3 code snippets so I started to post them on Twitter. Especially my little article about monitoring the CPU load with Cfengine 3 gained some attention there, that is why I am very motivated to dive in […]... Read More

Setting ACLs with the community version of Cfengine 3

As you might already know the community version of Cfengine 3 is not able to set ACLs the “Cfengine 3 way”. So when you are using the community edition of Cfengine 3 you have to find another way of doing it.. such as running shell commands out of the Cfengine 3 scripts. I hope the […]... Read More

Deleting old files with Cfengine 3

Cfengine 3 can be used to tidy your systems up on regular basis. Depending on the time, day of the week of the file extensions you are able to define how Cfengine 3 shall delete old and obsolete files. In today’s example a code snippet is shown which deletes all .gz files in /var/log which […]... Read More

Monitoring the CPU load with Cfengine 3

The creators of Cfengine 3 claim that their configuration management tool is able to perform a basic monitoring of important states, such as the CPU load. And indeed, with the help of Cfengine 3 you possibly get rid of some monitoring checks and therefore relive your monitoring system. This is doable because cf-monitord runs in […]... Read More

Using environment variables in Cfengine 3

Every Cfengine 2 script of my company contains environment variables. They are essential for configuring most of the services running on the different servers. For porting those scripts to Cfengine 3 one day I wanted to know how to make use of environment variables in the latest version of the configuration management tool. Well, the […]... Read More

Simple reporting with Cfengine 3

Keeping yourself up to date about what is happening on your Linux systems can be quite time-consuming. Many sys admins therefore use a little trick: Since the most important logs contain all the informative stuff, many admins install logcheck which reports unusual happenings every 60 minutes via mail. In this way, the admins stay informed […]... Read More
sdiff example output in less

Tools for Linux sysadmins #3: sdiff

Many Linux sysadmins have in common that working with configuration and other text files is part of their daily work. In my case, I often migrate older Linux boxes to our own Ubuntu fork. Therefore it is required to also use old configurations where it makes sense. When configuring and testing the applications on the […]... Read More

Cfengine3: Check for running services

In the last post about Cfengine 3 we talked about a simple script which creates a file and writes something into it. Today, we will create a simple example script which checks if two specified services are running. Writing the script Connect to your Linux box and create the following file: /var/lib/cfengine3/inputs/example2.cf body common control […]... Read More