Kubernetes

Introduction

Components

Control plane

• etcd(cluster parallel)
• kube-apiserver(parallel loadbalance)
• kube-controller-manager(single instance)
• kube-scheduler(single instance)

Data plane

• kubelet
• kube-proxy
• container-runtime(docker, containerd, rkt, ...)
• kube-dns

Options components

• kube-dashboard
• ingress-nginx
• metrics-server
• cni

Resources

Pods

# Pod template
apiVersion: V1
kind: Pod
metadata:
  annotations: {}
  labels: {}
  name: xxx
  namespace: xxx
spec:
  affnity:
    nodeAntiAffinity: {}
    podAntiAffinity: {}

  # Containers
  containers:
    # Args and Command
  - args: []
    command: []
    # Environment variables
    env: []
    envFrom: []
    # Image
    image: xxx:tag
    imagePullPolicy: IfNotPresent
    # Lifecycle
    lifecycle:
	  postStart: {}
	  preStop: {}
    # Name and Ports
    name: xxx
    ports: []
    # Health probes
    livenessProbe: {}
    readinessProbe: {}
    # Resources
    resources:
      limits: {}
      requests: {}
	# Volume mounts
	volumeMounts: []
  
  # imagePullSecrets
  imagePullSecrets: []
  
  # initContainers
  initContainers: []

  # others
  dnsPolicy: ClusterFirst
  restartPolicy: Always
  serviceAccount: xxx
  serviceAccountName: xxx
  tolerations: {}

  # Volume
  volumes: {}

Apps

Deployments -> ReplicaSets StatefulSets DaemonSets Jobs CronJobs

Service Discovery

Ingress: Service Endpoints LoadBalancer NodePort

LimitRange ResourceQuota HozizontalPodAutoscaler

Configmaps Secrets

PersistentVolumeClaim PersistentVolume StorageClass

Deploy

kubeadm

kubespray

Reference:

1. Official Website
2. Repository
3. Kustomize