Kubernetes is k8s
node is a machine
cluster is a set of nodes grouped together
multiple nodes helps in sharing the loads as well
who is the responsible for managing the cluster - master
how are the nodes are monitored?
master node is a another node with kubernetes installed in it and its configured as a master
master node watches over the nodes in the cluster
master node is the responsible for orchestration container on the worker nodes
components of k8s
1. API Server
2.etcd
3.schedulers
4.controllers
5.container runtime (docker)
6.kubelet
API server - front of the Kubernetes
What is etcd? etcd is an open source distributed key-value store used to hold and manage the critical information that distributed systems need to keep running
etcd used to manage the cluster
schedulers - the scheduler is responsible for distributing the work or containers across the nodes
newly created a containers and assigns them to the nodes
controllers - they are responsible for noticing & responding when nodes, containers or endpoints goes down
controllers are make decisions to bring up the new containers
kubelet is the agent that runs on each node in the cluster
the agents are responsible for making sure that
the containers are running on the nodes as expected
2 types of server master and workers nodes
and set of components that makes up Kubernetes
how are these components are distributed across different types of server?
in the other words, how does one server become a master and other the slave?
MASTER SERVER - kube-apiserver
WORKER SERVER - kubelet agent is responsible for interacting with master to provide the health information
etcd - key value store
master has etcd , controller, scheduler
kubectl run hello-minikube
kubectl cluster-info
kubectl get nodes