Kubernetes administration 🔗

Components of the cluster 🔗

ETCD 🔗

a key-base database that is high available. Used to store the current state of the cluster

kube-apiserver 🔗

Central api that all components use to ask for change or query info. Also is the API that we use with kubectl

Scheduler 🔗

In charge to decide to wich node each pod has to go

Kube Controller Manager 🔗

Manager of diferent logics in the k8s cluster

Kubelet 🔗

is the captian in each worker nodes

kube-proxy 🔗

A components does action to allow different worked nodes talk to each other

Components of an application 🔗

POD 🔗

• minimum components
• it can have 1 or more container

Replicaset 🔗

• ensures that n amount of containers are up at all time

Deployment 🔗

• allow to change pod from one version to another
  • rollout etc…
• the yaml definition is quite similar to the replicaset

Services 🔗

enable connectivity between pods

• Types:
  • Node port -> opens a port on the worked node, and maps this port to the pod
  • cluster ip -> creates a (virtual ?) ip in the cluster, grouping the pods in the same service. You use the service to communicate
  • load balancer -> to use a cloud LB