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Containers are just tar.gz files, you know? The whole layers thing it’s just an optimization. You can actually very simply run those tar.gz files without docke

Containers are just tar.gz files, you know? The whole layers thing it’s just an optimization. You can actually very simply run those tar.gz files without docker involved, just cgroups. But then you’ll have to write some daemon scripts to start, stop, restart, etc Follow this path and soon you’ll have a (worst) custom docker. Try to create a network out of those containers and soon a (worst) SDN network appears. Try to expand that to optimal node usage and soon a (worst) Kubernetes appears. My point here is: it’s just software packaged with their dependencies. The rest seems inconsequential, but it’s actually the hard part.

lamontcg 5y ago
"worst" might not really be all that bad. K8s may be the "worst" orchestrator for you, and you may not actually need all or any of that complexity/functionality. But starting with containers viewed as an RPM/tarball with some extra sauce (union filesystem and cgroups/jail) is a way better mental model than the whole "immutable infrastructure" meme to me.
z3t4 5y ago
You can do a lot with just SystemD today. Would not get surprised if SystemD would eat up Docker too.
- Art9681 5y ago
  I'm personally interested in Unikernels. That tech seems to be a good contender for replacing K8s. Every app an appliance running in a hypervisor.
  - dolmen 5y ago
    I even imagine a GOOS runtime for compiling a Go program that would talk directly to the hypervisor... Many services I write use only network resources, no disk.
treesknees 5y ago
This is essentially what fly.io does, they unpack the container image into a micro-VM and execute it directly. Calling it worse is subjective, you certainly need to account for things you would never worry about by using traditional Docker. But for some companies it ends up working much better than Docker. https://fly.io/blog/docker-without-docker/ https://fly.io/blog/docker-without-docker/
dolmen 5y ago
Images are just tar.gz. A container is a set of processes running from that image.

lamontcg 5y ago

"worst" might not really be all that bad. K8s may be the "worst" orchestrator for you, and you may not actually need all or any of that complexity/functionality. But starting with containers viewed as an RPM/tarball with some extra sauce (union filesystem and cgroups/jail) is a way better mental model than the whole "immutable infrastructure" meme to me.

z3t4 5y ago

You can do a lot with just SystemD today. Would not get surprised if SystemD would eat up Docker too.

Art9681 5y ago
I'm personally interested in Unikernels. That tech seems to be a good contender for replacing K8s. Every app an appliance running in a hypervisor.
- dolmen 5y ago
  I even imagine a GOOS runtime for compiling a Go program that would talk directly to the hypervisor... Many services I write use only network resources, no disk.

treesknees 5y ago

This is essentially what fly.io does, they unpack the container image into a micro-VM and execute it directly. Calling it worse is subjective, you certainly need to account for things you would never worry about by using traditional Docker. But for some companies it ends up working much better than Docker. https://fly.io/blog/docker-without-docker/ https://fly.io/blog/docker-without-docker/

dolmen 5y ago

Images are just tar.gz. A container is a set of processes running from that image.