VCluster

Virtual K8S Clusters

"látszólagos fürt"
a rezsicsökkentett fölhő

  1. Október - Papp Lajos
  1. What does it mean?
  2. Use-cases
  3. How does it work ?
  4. Under the hood

lalyos

  • mar az ovodaban in balna volt a jelem
  • Cofounder of SequenceIQ (docker + bigdata + felho)
  • BanzaiCloud in early times
  • long time dev (java/golang) (since 1998)
  • trainer/consultant (hire me!)

VCluster

A virtual k8s cluster which runs
in a namespace of a hosting cluster

Issues with k8s?

Issues with k8s?

  • [dev] You got restricted acces

Issues with k8s?

  • [dev] You got restricted acces
  • [dev] Don't want to chage existing apps

Issues with k8s?

  • [dev] You got restricted acces
  • [dev] Don't want to chage existing apps
  • [ops] Want less clusters to maintain

Real clusters

Moves

moves-4b

Virtual Clusters

Issues with k8s?

  • [dev] You got restricted acces
  • [dev] Don't want to chage existing apps
  • [ops] Want less clusters to maintain
  • [ops] Want Restrict acces by namspace

Issues with k8s?

  • [dev] You got restricted acces
  • [dev] Don't want to chage existing apps
  • [ops] Want less clusters to maintain
  • [ops] Want Restrict acces by namspace
  • [ops] Parallely run different versoins of …

Issues with k8s?

  • [dev] You got restricted acces
  • [dev] Don't want to chage existing apps
  • [ops] Want less clusters to maintain
  • [ops] Want Restrict acces by namspace
  • [ops] Parallely run different versoins of …
  • … more …
  • cloud provider APIServer customization ???
  • Stop under-utilized clusters
  • save costs (megvedjuk a magyar …)
  • Everybody gets a cluster

Usage

  • vcluster cli
  • collect CIDR addr
  • generate KUBECONFIG
  • helm

RBAC: be able to start a pod

Exposing

  • internal only
  • NodePort
  • Loadbalancer
  • Ingress

Accessing a VCluster

$ > vcluster connect my-vcluster

generates KUBECONFIG yaml

How?

Vcluster has its own ctrl-plane

  • APIServer
  • Controller mgr
  • Storage (etcd/kine)
  • Scheduler ???

How k8s works normally:

training slides - thanks jpetazzo

KINE

Part/Subproject of K3S.io

Kine Is Not Etcd

Run Kubernetes on MySQL, Postgres, sqlite, dqlite, not etcd.

sqlite + litestream + s3 => dirt cheap,

Scheduler

By default you delegate it to the host cluster. But…

  • Labeling nodes inside has no effect
  • Draining or tainting nodes inside
  • You cannot use custom schedulers inside

vcluster supports running a scheduler inside

DNS - Network

service mapping is configurable

Nodes

supports multiple sync modes:

  • Fake Nodes (def)
  • Real Nodes
  • Real Nodes All
  • Real Nodes Label Selector

daemonsets?

Synched Resources

pods, services, configmaps, secrets, events (other way), PVCs, Ingresses

configurable

sdk for custom resource syncers plugins (depl,sts,ns)

Extra Features

  • Pausing & Resuming
  • High Availability
  • Distro choise: k3s/k0s/vanillia k8s
  • Backup & Restore (Velero)

DinD / KinK

Keep in touch

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