# VCluster ## Virtual K8S Clusters > "látszólagos fürt" > a rezsicsökkentett fölhő 2022. Október - Papp Lajos --- 0. What does it mean? 1. Use-cases 2. How does it work ? 3. 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  --- ## 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](https://lisa-2019-10.container.training/tutorial.yml.html#27) ---  --- ## 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 - http://hwsw.lalyo.sh/