Building AWS AMIs from scratch is the practice many security-focused organizations strictly follow.
I have been building custom AWS AMIs from scratch for my personal AWS environment for many years. Looking at my personal AMI collection, I have custom AMIs dating back to CentOS 5.
A few days ago I decided to do another refresh of my AWS environment and started with a new and improved build of CentOS 7.9. I rehashed my packer build merging in several improvements. OVA creation went flawless and AWS vmimport successfully finished. When I booted my new AMI to upgrade CentOS stock kernel to the latest kernel-lt 5.4, I noticed that DNS resolution is failing and that /etc/resolv.conf did not get updated correctly:
I had to troubleshooting and fix DHCP on my new image.
