The actual PaaS relies pretty heavily on AWS Cloud Formation - it predates swarm, mesosphere, kube, etc. So when we deploy a new version of a service, it's really "deploy an auto scaling group of EC2 instances across several AZs fronted by an ELB, then there's an automatic DNS change made which makes the new stack of EC2 instances live once the new stack is validated as working". The upside of the one service per EC2 image approach is no multi-tenancy interference - downsides are cost and it takes a bit longer to deploy. There's a project underway to switch compute to being Kube-based though, so that's promising.
All this is apples and oranges though - solns for big companies don't make sense for a 1-person shop. I still have side projects being deployed via ansible and git pull instead of Docker, because it hasn't been worth the ROI to upgrade to the latter.
Re asparck - yeah, it was my personal site but I struggled to find the time to work on it. In the end I decided it was better to have it offline than terribly out of date, but hopefully I'll resurrect it some day.
Asking because is one of the conceptual things I've been trying to figure out.
Still currently using non Docker deployment of production stuff for our public services. Have looked at Docker a few times, but for deployment to the public internet where being accessible to clients on both IPv4 and IPv6 is mandatory, it just doesn't seem to suit.
Docker (swarm) doesn't seem to do IPv6 at all, and the general networking approach in non-swarm docker seems insecure as hell for public services + it also seems to change arbitrarily between versions. For a (currently) 1 man setup, it seems like a bad use of time to have to keep on top of. ;)
Maybe using Nginx on the public services, reverse proxying to not-publicly-accessible docker container hosts would be the right approach instead?
Btw - asparck.com (as per your profile info) doesn't seem to be online?