How To Copy Key Pairs To Another AWS Region Using The ssh-keygen Command

Author: , August 4th, 2021

I wanted to use the same SSH keys for multiple AWS regions. As it turns out, AWS simply stores the public key when you download the private key as a .pem file. The solution is to simply generate the public key locally from the existing .pem, then import the public key using the same name […]

How To Fix Email Service Unavailable Delivery Issues with IPv6 on Amazon Linux

Author: , July 16th, 2021

PROBLEM: Email delivery to Google was failing with a “Service Unavailable” error:

Note that the network address for the destination is shown as IPv6! That is the root cause of the issue: 1. Sendmail is sending mail from the IPv6 address instead of the IPv4 address 2. Google rejects IPv6 senders without proper reverse […]

How To Search the APT Sources for Available Packages

Author: , June 10th, 2021

Search for a string:

List all packages:

How To Convert from AWS Instance Family t2 to t3 with Enhanced Networking on Amazon Linux 1

Author: , June 10th, 2021

I wanted to change instance type from t2 to t3, but got an error when i went to start the instance:

I found this AWS docs page: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking-ena.html Below are the steps I need to follow on AWS Linux 1. Summary Steps Pre-flight tests on t2 modinfo ena -> see “ERROR: modinfo: could not […]

How To Expand an NVMe EBS Volumes After a Disk Resize on Amazon Linux

Author: , February 19th, 2021

First, use lsblk to see the raw partitions:

Note how the partition at 259:1 is only 20GB, while the entire disk at 259:0 is 40GB. A partition resize is required in this case.

For an EXT4 filesystem, use the resize2fs command instead:

For more information, please visit the AMW Docs: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/recognize-expanded-volume-linux.html

How To Fix “IOError: [Errno 10] No child processes” When Running the aws CLI Command from Perl WWW-REST-Apid

Author: , December 3rd, 2020

Problem While running the aws cli command from a Perl async command inside apid, I go the following error:

Solution The issue turned out to be a bug in Python2.7, so I upgraded to Python3.4, then uninstalled and re-installed the aws cli software so that it used the proper Python34 version. Procedure

https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2-linux.html […]

How To Install MySQL 8.0 on AWS Linux 2

Author: , November 18th, 2020

How To Upgrade Certbot, Python and PIP on AWS Linux 1

Author: , May 6th, 2020

I ran letsencrypt-auto renew and got the following error:

The solution in this article gave me the answer:

Turns out Python was old at version 2.7, so did the following also:

Also had to change the cron job script to call certbot directly instead of letsencrypt-auto : vi /root/letsencrypt-cron.sh

How To Downgrade PIP After Upgrade on Amazon Linux

Author: , March 25th, 2020

I tried upgrading pip when prompted to do so: sudo pip install –upgrade pip This worked, but removed the system install in /usr/bin/pip and replaced it with /usr/local/bin/pip – NOT GOOD! The solution is as follows:

How To Show the Origin in Git

Author: , January 30th, 2020

Recently, I wanted to see the “origin” of the git repository I was working in. The command is: git remote -v For example: