How To Clear All iptables Rules

Author: , March 20th, 2024

How To Diff Two Files In Vim

Author: , February 5th, 2024

shell> vim file1 file2 Create a vertical split window: Control-w v Enable visual diff on the left side: :diffthis Move the cursor to the right side buffer: Control-w Right-arrow Enable visual diff on the left side: :diffthis You should now see the differences highlighted on both sides.

How To Display All Virtual Hosts Defined for Apache 2

Author: , January 29th, 2024

How To Fix perl: symbol lookup error: undefined symbol: Perl_xs_handshake

Author: , November 9th, 2023

This was caused by having the PERL5LIB environment variable set.

How To Secure Self-Hosted Bamboo and Crucible with Let’s Encrypt SSL Certificates

Author: , September 14th, 2023

Summary In this blog we explore how to use certificates from Let’s Encrypt to secure self-hosted Bamboo and Crucible. Process To Follow Install Certbot Ensure that external DNS resolves to the correct IP addressping Ensure that Port 80 is open from the outside to that IP address so that Let’s Encrypt can validate the […]

How to add and delete security group rules in AWS via the CLI (and list them too!)

Author: , September 13th, 2023

Add inbound rule(s) for a security group ID:

## Delete inbound rule(s) for a security group ID

## List security groups by security group ID

## List inbound rules for a specific security group ID

Thanks to:

How To Use SSL With sysbench To Test MySQL Server

Author: , September 7th, 2023

SUMMARY If sysbench is started with the “–mysql-ssl=on” option, it looks in the current directory for the following files:

PROCEDURE Locate the current MySQL database certificates, usually in /var/lib/mysql, and make sure that the OS user running sysbench is able to read the following 3 files:

Next, cd to the OS user’s home […]

How To Upgrade MySQL to 8.0 on CentOS/AWS Linux

Author: , August 31st, 2023

START: Server version: 5.7.43-log MySQL Community Server (GPL) FINISH: Server version: 8.0.34-log MySQL Community Server (GPL) Check and veify your my.cnf ssl entries if you see the following error in the /var/log/mysqld.log file at startup:

How To Save iptables To Disk On Amazon Linux 2

Author: , July 21st, 2023

I wanted to save the iptables list to disk, but got an error when I tried: # service iptables save The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl. The solution was to install the iptables-services package: # yum install iptables-services […]

How To Fix Error “Wrong Fs Type, Bad Option, Bad Superblock” When Mounting a Filesystem

Author: , June 23rd, 2023

When trying to mount can XFS filestsen on an AWS instance, I got the error “mount: wrong fs type, bad option, bad superblock on /dev/sdh” Examine the volume’s UUID with the xfs_db command: shell> sudo xfs_db -c uuid /dev/nvme2n1 To fix the problem, you have two options… Temporary Solution Add nouuid mount option to temporarily […]