Automation with Cron job on Centos 8

Adapted from digital ocean reference.

Introduction

Cron is a time-based job scheduling daemon found in Unix-like operating systems, including Linux distributions. Cron runs in the background and tasks scheduled with cron, referred to as “cron jobs,” are executed automatically, making cron useful for automating maintenance-related tasks.

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How to install and configure fail2ban on CentOS 7

Fail2ban is available through the EPEL project. So it needs to be installed first.

Install

sudo yum install epel-release
sudo yum install fail2ban
sudo systemctl enable fail2ban
sudo systemctl start fail2ban
sudo systemctl status fail2ban

Configure

Configuration files is located in the /etc/fail2ban directory. Leave the jail.conf as default and create your own config file called /etc/fail2ban/jail.d/jail.local. The values defined in jail.local will take precedent over jail.conf.

sudo touch /etc/fail2ban/jail.d/jail.local
sudo vim /etc/fail2ban/jail.d/jail.local

add the content to it as needed. below is a sample content

[DEFAULT]
# Ban hosts for one hour:
bantime = 3600

# Override /etc/fail2ban/jail.d/00-firewalld.conf:
banaction = iptables-multiport

[sshd]
enabled = true

[nginx-http-auth]
enabled = true
sudo systemctl restart fail2ban
sudo systemctl status fail2ban

Monitor

sudo fail2ban-client status
sudo fail2ban-client status jail_name
sudo tail -F /var/log/fail2ban.log

How to extend partition size in Centos7

I have a local OS repository that is used by my local machines to get the Centos updates from.

I realised it has stopped working and it turned out that the disk is full.

The machine is hosted on a VMWare ESXi 6.7 server. Below are the steps needed to go through to get the partition size extended.

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How to install and configure Asciidoctor PDF

What is AsciiDoc

From asciidoc.org

AsciiDoc is a text document format for writing notes, documentation, articles, books, ebooks, slideshows, web pages, man pages and blogs. AsciiDoc files can be translated to many formats including HTML, PDF, EPUB, man page.

AsciiDoc is highly configurable: both the AsciiDoc source file syntax and the backend output markups (which can be almost any type of SGML/XML markup) can be customized and extended by the user.

asciidoc.org
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