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 […]

How To Fix Error “Cannot open access to console, the root account is locked”

Author: , June 23rd, 2023

When trying to access the serial console on AWS, I got the following error: Cannot open access to console, the root account is locked Since I had edited /etc/fstab, the host would not boot. The only way to fix this problem is to unmount the root volume from the affected instance, mount it on another […]

How To Fix Mouse Scrolls the Command Line History Instead of the Window Buffer in Terminal

Author: , May 23rd, 2023

In the macOS Terminal, my mouse scroll wheel would magically start scrolling the command line history instead of the window buffer scroll bar on the right to show window history. This happened when an SSH session was disconnected or timed out. The fix is to run the reset command.

How To Enable SSH Login From OS X Yosemite 10.10.5 to macOS Ventura 13.3.1

Author: , May 19th, 2023

I was unable to login from my old iMac running Yosemite to my new iMac running Ventura using RSA keys. It turns out that RSA key support was disabled in Ventura. To correct the problem, I added the following two lines to the bottom of /etc/ssh/sshd_config:

How To Fix SSH Permission Denied From macOS Ventura To Amazon Linux

Author: , May 9th, 2023

I have been using RSA SSH keys forever to login to my various AWS EC2 instances. With macOS Ventura 13.3.1 ssh failed with the “Permission Denied” error. Using ssh -vvv, I saw that the RSA key was now being rejected. After much research, I decided to implement new keys on the client (Ventura) side using […]