(disclaimer: new to AWS, a developer trying to pivot into DevOps)
During one interview/screening, I took a take-home challenge, which asked me to provision a complex piece of infrastructure, using their own script, which relied on Terraform, and created a little cosmos of intertwined AWS resources. Unfortunatelly, I manually (yuck!) deleted the S3 bucket used by Terraform to keep track of the state of things - so destroying them automatically is no longer possible, so I need to clean it all up manually.
Most of the things are cleared now. But there's a Security Group that's left over. Deleting it fails due to it being connected to something called Network Interface. Looking at that Network Interface I found out that "Delete" button is greyed out, but "Detach" is active - alas, it said I can't "Detach" it, because I "lack permissions". Given the fact that I'm logged into console as a root of my AWS account, I don't buy it.
Does anyone know what these beasts are, and what are the possible problems killing them? I suppose it's kinda like a connection between A and B, and if either end of a connection is plugged in, you can't "kill" it - but what should I look for?