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The biggest issue I have with Kubernetes is it doesn't downscale. I have a lot of projects that don't need a cluster. A single node is enough. But Kubernetes ha

The biggest issue I have with Kubernetes is it doesn't downscale. I have a lot of projects that don't need a cluster. A single node is enough. But Kubernetes has too much CPU and RAM overhead in such a configuration. Because of this, I'm forced to either use another orchestrator (Docker Swarm is lightweight enough to work on a single node or a small cluster), or pay for machines I don't really need. What are is the current thinking on this issue at Rancher?

hauxir 8y ago
have you tried dokku? https://github.com/dokku/dokku https://github.com/dokku/dokku
- ngrilly 8y ago
  Apps are usually composed of several services working together, each service being in its own container. I'd like to be able to use something like docker-compose.yml to describe this. And it looks like Dokku doesn't do this.
falcolas 8y ago
Have you considered stepping back and wondering if you really need orchestration at this scale? Couldn't a simple unit file suffice? If you have many such projects, perhaps something like Saltstack or Ansible, both of which have support for Docker container management built in.
- ngrilly 8y ago
  Great question! I already use Ansible to setup machines and automate deployments. I used systemd unit files until I switched to Docker. I don't use them anymore since dockerd supervises the container itself. I use Docker Compose to describe the set of services composing my app and it's great. But in production, Docker Compose is unable to provide zero-downtime deployments, and this is why I'm looking at Docker Swarm or Kubernetes. systemd unit files are not very useful for Docker containers, and they don't solve the zero-downtime deployment issue.
snug 8y ago
Have you looked at using a managed kubernetes service like GKE, you still lose about 10% of your resources, but you're not paying for the master. You could even look at something like Google App Engine.
- ngrilly 8y ago
  No, I haven't because I thought the overhead was bigger. Are you saying that the overhead on the worker nodes is about 10 % for the kubelet, the containerd and the logging daemons? GKE documentation says 25 % of the first 4 GB are reserved for GKE: https://cloud.google.com/kubernetes-engine/docs/concepts/cluster-architecture#memory_cpu https://cloud.google.com/kubernetes-engine/docs/concepts/clu...

hauxir 8y ago

have you tried dokku? https://github.com/dokku/dokku https://github.com/dokku/dokku

ngrilly 8y ago
Apps are usually composed of several services working together, each service being in its own container. I'd like to be able to use something like docker-compose.yml to describe this. And it looks like Dokku doesn't do this.

falcolas 8y ago

Have you considered stepping back and wondering if you really need orchestration at this scale? Couldn't a simple unit file suffice? If you have many such projects, perhaps something like Saltstack or Ansible, both of which have support for Docker container management built in.

ngrilly 8y ago
Great question! I already use Ansible to setup machines and automate deployments. I used systemd unit files until I switched to Docker. I don't use them anymore since dockerd supervises the container itself. I use Docker Compose to describe the set of services composing my app and it's great. But in production, Docker Compose is unable to provide zero-downtime deployments, and this is why I'm looking at Docker Swarm or Kubernetes. systemd unit files are not very useful for Docker containers, and they don't solve the zero-downtime deployment issue.

snug 8y ago

Have you looked at using a managed kubernetes service like GKE, you still lose about 10% of your resources, but you're not paying for the master. You could even look at something like Google App Engine.

ngrilly 8y ago
No, I haven't because I thought the overhead was bigger. Are you saying that the overhead on the worker nodes is about 10 % for the kubelet, the containerd and the logging daemons? GKE documentation says 25 % of the first 4 GB are reserved for GKE: https://cloud.google.com/kubernetes-engine/docs/concepts/cluster-architecture#memory_cpu https://cloud.google.com/kubernetes-engine/docs/concepts/clu...