k8s service资源

#service：负载均衡，服务的自动发现   service帮助pod暴露端口
#创建一个service
cd k8s_yaml/
mkdir svc
vim k8s_svc.yaml
apiVersion: v1
kind: Service   #简称svc
metadata:
  name: myweb
spec:
  type: NodePort  #默认ClusterIP
  ports:
    - port: 80          #clusterIP
      nodePort: 30000   #node port
      targetPort: 80    #pod port
  selector:
    app: myweb2

kubectl create -f k8s_svc.yaml 
kubectl edit svc myweb
  selector:
    app: myweb
改为myweb
kubectl edit rc nginx
spec:
  replicas: 2
数量改为2
#检测
[root@k8s-master ~]# kubectl describe svc myweb
Name:            myweb
Namespace:        default
Labels:            <none>
Selector:        app=myweb
Type:            NodePort
IP:            10.254.16.176
Port:            <unset> 80/TCP
NodePort:        <unset> 30000/TCP
Endpoints:        172.18.35.2:80,172.18.35.3:80
Session Affinity:    None
No events.

kubectl exec -it nginx-ls85f /bin/bash
echo 'web01'>/usr/share/nginx/html/index.html 
kubectl exec -it nginx-mvq25 /bin/bash
echo 'web02'>/usr/share/nginx/html/index.html 
curl -I 10.0.0.13:30000
curl -I 10.0.0.12:30000
[root@k8s-master ~]# curl  10.0.0.12:30000
web02
[root@k8s-master ~]# curl  10.0.0.12:30000
web01

kubectl scale rc nginx --replicas=2   #调整rc的副本书
kubectl  exec  -it   pod_name  /bin/bash   #进入pod容器
#修改nodePort范围
vim  /etc/kubernetes/apiserver
KUBE_API_ARGS="--service-node-port-range=3000-60000"
#命令行创建service资源
kubectl expose rc nginx --type=NodePort --port=80
service默认使用iptables来实现负载均衡, k8s 1.8新版本中推荐使用lvs(四层负载均衡 传输层tcp,udp)