Service

apiVersion: v1
kind: Service
metadata:
  name: clusterip1
spec:
  selector:
    svc: clusterip
  ports:
  - port: 80
    targetPort: 8080

apiVersion: v1
kind: Pod
metadata:
  name: pod1
  labels:
    svc: clusterip
spec:
  containers:
  - name: container
    image: kubetm/app

apiVersion: v1
kind: Pod
metadata:
  name: request-pod
spec:
  containers:
  - name: container
    image: kubetm/init

kubectl exec request-pod -it /bin/bash

nslookup clusterip1
nslookup clusterip1.default.svc.cluster.local

curl clusterip1/hostname
curl clusterip1.default.svc.cluster.local/hostname

apiVersion: v1
kind: Service
metadata:
  name: headless1
spec:
  selector:
    svc: headless
  ports:
    - port: 80
      targetPort: 8080    
  clusterIP: None

apiVersion: v1
kind: Pod
metadata:
  name: pod4
  labels:
    svc: headless
spec:
  hostname: pod-a
  subdomain: headless1
  containers:
  - name: container
    image: kubetm/app

nslookup headless1
nslookup pod-a.headless1
nslookup pod-b.headless1

curl pod-a.headless1:8080/hostname
curl pod-b.headless1:8080/hostname

apiVersion: v1
kind: Service
metadata:
  name: endpoint1
spec:
  selector:
    svc: endpoint
  ports:
  - port: 8080

apiVersion: v1
kind: Pod
metadata:
  name: pod7
  labels:
    svc: endpoint
spec:
  containers:
  - name: container
    image: kubetm/app

kubectl describe endpoints endpoint1

apiVersion: v1
kind: Service
metadata:
  name: endpoint2
spec:
  ports:
  - port: 8080

apiVersion: v1
kind: Pod
metadata:
  name: pod9
spec:
  containers:
  - name: container
    image: kubetm/app

apiVersion: v1
kind: Endpoints
metadata:
  name: endpoint2
subsets:
 - addresses:
   - ip: 20.109.5.12
   ports:
   - port: 8080

curl endpoint2:8080/hostname

apiVersion: v1
kind: Service
metadata:
  name: endpoint3
spec:
  ports:
  - port: 80

nslookup https://www.github.com
curl -O 185.199.110.153:80/kubetm/kubetm.github.io/blob/master/documents/intermediate/Service-Headless_ExternalName.pdf

apiVersion: v1
kind: Endpoints
metadata:
  name: endpoint3
subsets:
 - addresses:
   - ip: 185.199.110.153
   ports:
   - port: 80

curl -O endpoint3/kubetm/kubetm.github.io/blob/master/documents/intermediate/Service-Headless_ExternalName.pdf

apiVersion: v1
kind: Service
metadata:
 name: externalname1
spec:
 type: ExternalName
 externalName: github.github.io

curl -O externalname1/kubetm/kubetm.github.io/blob/master/documents/intermediate/Service-Headless_ExternalName.pdf

apiVersion: v1
kind: Service
metadata:
  name: headless1
spec:
  selector:             # 생략시 Endpoints 직접 생성해서 사용
    svc: headless
  ports:
    - port: 80
      targetPort: 8080    
  clusterIP: None       # headless 서비스  
  type: ExternalName    # ExternalName Service 설정시 사용
  externalName: github.github.io  # ExternalName사용시 연결 Domain지정

apiVersion: v1
kind: Endpoints
metadata:
  name: headless1       # Service의 이름과 동일하게 지정
subsets:
 - addresses:
   - ip: 20.109.5.12    # Pod의 ClusterIp
   ports:
   - port: 8080         # Pod의 Container Port

apiVersion: v1
kind: Pod
metadata:
  name: pod4
  labels:
    svc: headless
spec:
  hostname: pod-a       # 호스트네임 설정, 생략시 Pod Name이 적용됨
  subdomain: headless1  # headless 서비스 사용시 Service의 이름으로 지정
  containers:
  - name: container
    image: kubetm/app

# Pod이름이 request-pod인 Container로 들어가기 (나올땐 exit)
kubectl exec request-pod -it /bin/bash

# Endpoints 상세보기
kubectl describe endpoints endpoint1