Brian Kernighan on the origins of Unix

I personally found that Docker Swarm actually did reasonably well for the middle. The user experience was pretty good and it was really easy to set-up. Together with docker-compose for the configuration you could get fairly complicated set-ups working pretty quickly with sensible defaults.

Its main problem was that the implementation was plagued with bugs that made it really annoying to run in production. When its internal state got corrupted (which was often in the beginning) the only fix was to blow away the entire cluster. Which is really annoying when you've got a hundreds of containers spread over dozens of nodes. Bringing everything up at once was a guaranteed way to get more corrupted state.

It's better now, and it's has been pretty stable for a while, but the mind share has all gone to k8s. Swarm is good for smaller set-ups, but if you want to build another layer of automation on top of it, Swarm is a real pain while k8s does this easily. Silly things like secrets that can't be updated are just nails in the coffin.

I've wondered about how the world would have turned out if the Swarm UI could have been merged with a k8s reliable backend. I see there is something called Kompose, but I've never tried it.