Simple CMDB import using Icinga Director

In my last article I focussed on Icinga 2 and the new configuration utility Icinga Director. I mentioned that Icinga Director can be used to link Icinga to pre-existing  Configuration Management Database (CMDB) systems to simplify data import. In this article we will create a little “dummy CMDB” with MySQL and automatically import and deploy host information. Using Icinga
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Install Icinga2, Icinga Web 2 and Icinga Director under EL7

Icinga2 is a very powerful monitoring system that can be used optionally with the new user interface Icinga Web 2. In comparison with Icinga 1.x, those tools have been developed completely from scratch – they have nothing in common with the legacy software stack. This year, a configuration utility named Icinga Director has been released.
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Integrate source code patches into RPM packages

Rcently I packaged the software scponly for Enteprise Linux using rpmbuild and stumbled upon an error message: $ cd ~/rpmbuild/SPECS $ rpmbuild -ba scponly.spec checking for libgiertz… … /usr/bin/install -c -o 0 -g 0 scponly /home/cstan/rpmbuild/BUILDROOT/scponly-4.8-1.el7.centos.x86_64/usr/bin/scponly /usr/bin/install: cannot change ownership of ‘/home/cstan/rpmbuild/BUILDROOT/scponly-4.8-1.el7.centos.x86_64/usr/bin/scponly’: Operation not permitted make: *** [install] Error 1 error: Bad exit status from
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Short tip: sudo and vi(m)

System administrators know requirements like this – a dedicated server needs to be deployed for a new application. In order to enable owners to maintain their application they need permissions to modify relevant configuration files. In this scenario, sudo rules are often configured in a way to enable file modifications and also utilities to reload the application
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Spoiled for choice: new HDDs for my NAS

2016 seems to be the year of big hardware renewals for me – after completely overhauling my virtual infrastructure, I also needed new hard drives for my NAS after nearly 4 years. NAS, DAS, what? For many years, I have been using D.I.Y. NAS servers for collecting my data and media library on a single host. After I was
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Short tip: Enterprise Linux 7 and annoying prompts in GNU Screen titles

If you want to combine multiple terminal sessions on one window, multiplexers such as tmux or GNU Screen are useful tools. I have been using screen for 10 years with the following configuration: $ cat ~/.screenrc #F7+F8 for tab switching bindkey -k k7 prev bindkey -k k8 next #disable welcome startup_message off #screen line with
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Monitoring OMD sites with check_omd

Using OMD it is possible to setup a working monitoring for checking infrastructure setups just within minutes. But – what monitored OMD-relevant processes? Usually, a OMD site consists of multiple pre-configured services such as: Icinga or Nagios Apache web server Cron service rrdcached (for RRD graphs) npcd (performance data) For checking the functionality of a
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Monitor systemd units with Nagios/Icinga

Recently I stumbled upon an interesting blog post about monitoring systemd units with Nagios or Icinga. But in my opinion the post’s screenshot is misleading. I looks like the linked Python scripts automatically discovers and configures systemd units within Nagios/Icinga – which is not the case. The script named pynagsystemd utilizes the systemctl command to check the state of all
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Create SELinux module for NRPE and check_fail2ban

If you need to protect a Linux host against unauthorized access, fail2ban is a very handy service. The application scans log files of various services, automatically detects failed logins and blocks attacker’s IP addresses. Especially on public hosts, it is essential to implement a protection like this on prominent services like SSH. For monitoring bans, the
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