posts

UFW Firewall- Comprehensive Guide: install & configuration

FreeIPA - I’ve been running FreeIPA for quite some time now on a Rocky Linux 8.9 server. Never had any major issues with it so far. That until last night when I’ve performed a full packages upgrade on server (ipa included, all packages). After upgrade, all IPA packages were version 4.9.12-11.module+el8.9.0+1652+4ee71f6a.

Boost 1.60 - RPM packages for CentOS 7.x linux distro. Packages have been built from a source package downloaded from Springdale Institute for Advanced Study repository.

glibc-debug - While trying to figure out a specific challange to ctflearn website, I had to run gdb on a binary file to try to get some debug info from there. My CentOS 8.x said I need to install the glibc-debug package in order to get access to all the available debug info generated by gdb.

CentOS 8 Stream - You have probably heard the news that CentOS era is gone. CentOS 8 will continue though as a CentOS Stream version you should upgrade to before the end of 2021.

fd-find - is a simple, fast and friendly alternative to the classic linux find comand. Please take into consideration that this tool is a not a find replacement and it might be missing some of the features linux find has but it’s pretty close to it so it provides around 80% of the default find options and features

Magento2 Varnish CWP template - One of my projects from freelancer.com involved the configuration of a linux server, with a hosting panel (preferrably an open source or free one) for an online store built using Magento2. Mandatory requirement: Varnish as a caching mechanism since the website speed was an important factor.

Bash scripting is fun and can help you automate a lot of things on your linux servers.

Pimcore - An award-winning software, which delivers significant business value by breaking up data silos that exist in many enterprises. Or so they say. True or not, I don’t really care.

USB passthrough to a KVM guest instance - Main server running: CentOS 7.7 x64 latest version. KVM guest machine running RHEL-7.4 (Maipo) but it can be any linux flavor.

Iptables is a user-space utility program that allows a system administrator to configure the IP packet filter rules of the Linux kernel firewall, implemented as different Netfilter modules.

ZeroMQ - a software library that lets you quickly design and implement a fast message-based application!

CentOS 5.x is old and EOL. But there are still lots of servers running this version.

If you want to monitor services running on yourlinux machine you have multiple options. But if you don’t want to install any additional software or applications, you can do it with a very simple perl script. (you need MIME::Lite module to be installed though).

Incron is a daemon which monitors filesystem events and executes commands defined in system and user tables. It can be installed on all major linux distributions using each distribution’s default package manager.

Dropbox - It was never on my favourite list because I’ve always used Google Drive. But since I didn’t want to use my Google Drive to store some specific files I’ve decided to give Dropbox a try on my CentOS 7 server.

Nagios - Plugin to check CPU temperature! I like to monitor every aspect of my linux servers and one of these aspects is the CPU temperature. Most common way to find out your CPU temperature for pretty much any linux distribution is to use the package lm_sensors. It’s quite simple to install it:

Jasmin SMS Gateway - We use ELK as a centralized logging solution. That means we have an ElasticSearch cluster, a LogStash Cluster, Kibana and Grafana.

MacOS Sierra and MacOS High Sierra has some DNS issues when connected to my work VPN using a “Cisco IPSEC VPN“ connection, the DNS resolver is not working as expected.

LXC - I was recently trying to resize a lxc container from my proxmox server (I’m running the latest proxmox version). Even though I have increased the disk space assigned to that container, for some reason I was not able to actually see the new size of the disk inside the container.

CentOS 7 - If you forgot root password the first thing that might cross your mind would be to boot in single user mode and reset the root password from there. That was working just fine in CentOS 5.x or CentOS 6.x but in 7.0 the things are a little bit different.

mod_pagespeed - Easy install of mod_pagespeed on a cPanel/WHM server with EasyApache4 (please note that with EasyApache3 you could have just added a custom mode to EasyApache and recompile apache with the new mode).

Wordpress is one of the most use CMS platforms for blogs and websites. It’s fast, highly customizable and pretty easy to use. You can use it for your personal blog, you can build a personal or business website, an online store and basically, it can be used to build any type of website.

I am using BackupPC as a backup solution for my linux box and recently modifying some settings I got a huge backup instead of the regular one. So I have deleted only those files that were extra… But the space was still occupied on my hard disk even if the files have been deleted.

Spamassassin - Best free open source software for email server in order to fight spam. A simple yet very powerfull perl script which generates spamassasin spam filte rules. These rules can be used to block certain types of emails based on “email body content.

Postfix - one of the most used open source mail server software. Let’s create a simple spam filter running on your linux box using SpamAssassin and Postfix. It basically works on any linux distribution which has these 2 packages installed.

mod_evasive - Adds an extra protection layer to the Apache web server.

Apache: No space left on device: Couldn’t create accept lock - an interesting error. I can’t really remember if I did or modified anything to my apache web server configuration but for some reason I got a notification stating that my web server is down.

mod_ruid2 - a suexec apache module which takes the advantage of POSIX. If you want to manually install the module for the apache web server on a linux centos server:

Zabbix-2.4.5 installation problem. I have recently tried to install Zabbix 2.4.5 on my linux CentOS 6.6 x64, from the official RPM packages from official zabbix website. Everything went smooth until I tried to setup the web interface.

mod_lsapi - apache module based on litespeed technologies API for PHP. How to install and use it without running CloudLinux kernel.