Follow these simple steps to resize a Virtual machine disk (vmdk) and then extend the volume using LVM. Make sure that you have/make a backup before carrying out these steps. First go ahead and extend the vmdk from ESXi/vCenter. I increased the disk size from...
When trying to get the custom time range for PNP4Nagios graphs, it might result in an error "application/models/data.php [664]:". It can easily resolved by editing "system.php" in PNP4Nagios controllers folder. To start with first make a backup of the file. # cp -a...
It's now possible to install both Puppet Master and Agent on the same host with different certs for each, to avoid future conflicts when managing master server with puppet. You need to have 2 seperate entries on puppet.conf, one in [master] and one in [agent] so that...
Its now possible to install the latest version of Nagios NRPE v 3.0.1 (source install) on RaspberryPi (incl. Pixel OS). Just follow this simple article and you will be up and running with NRPE on Nagios clients as well as on the Nagios server which needs to...
The process of replacing the default SSL certificates on ESXi 6.x/6.5 is a simple process involving around 5-10 steps. We would need a seperate linux host to generate the openssl self-signed certificate (NOTE: we are not using any CA). Host needs to be in Host...
This article shows you how to Automate iptables for the whole infrastructure (linux/unix) and maintain the state during the lifecycle of a host. We would need to install 2 modules from PuppetLabs so that we can assign Rules based on the requirements, whether its from...
To generate a SHA256 certficate in linux all you need to do is run this openssl command and you will be ready with a PCI compliant cert. This is a standard requirement nowadays in any PCI compliant environment. This is implemented with Apache backend. Run the below...
To make Nagios CORE security compliant with a SHA2/SHA256 cert, follow these steps using Openssl and you will be ready in no time with a PCI compliant cert. This is a standard requirement nowadays in any PCI compliant environment. This is implemented with Apache...
In Raspberry Pi from version Jessie onwards the "root" login for SSH sessions (via Putty Login) has been disabled by default. It can be enabled by just editing "sshd_config" file and then restarting "ssh" service. To start with login to raspi via ssh using the default...
When adding multiple users in IDM/freeIPA its a pain inputting each user and its time consuming. This script/one liner allows you to enter multiple users at one go and it includes non-interactively specifying a password. The following script allows creating multipe...
This script is to monitor a failure when Nagios daemons fails to start or sometimes Nagios stops sending alerts. When you check the logs at "/usr/local/nagios/var/log/nagios.log" you might come across messages like "Caught SIGSEGV, shutting down". These messages need...
This article covers the setup and configuration of PuppetDB and Puppetmaster on separate nodes/hosts. I have used PostgreSQL as PuppetDB backend instead of HSQLDB as it's much easier to query and troubleshoot any issues you comes across especially when using Puppet...