k8s of Service Introduction and presentation

When we use the pod, the pod can ping each other before, the machine itself can ping another pod and pod machine, if it is a serivce, we pass the port number, you can access the service. Source: https://github.com/limingios/docker/tree/master/No.10

Do not direct the use and management Pods, Why?

• When we do use ReplicaSet or ReplicationController horizontal expansion of scale, Pods may be ending.
• When we use the Deployment of us to update Docker Image Version, old Pods will be over, and then create a new Pods, Ip address has changed.

Service

• kubectl expoese command will give us the pod to create a Service, for external access.
• Service There are three main types:

1. ClsterIP
2. NodePort
3. LoadBalancer

• Alternatively, you can use DNS, but requires a DNS add-on

Service demo

• Create a service.

 

get pod
kubectl get pod -o wide
kubectl expose pods nginx
#查看到已经创建的service
kubectl get  svc

• Access service

 

ping 10.254.233.245

• Creating deployment

 

 cd deployk8s-master/
 cd labs/
 cd deployment/
more deployment_nginx.yml

 

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.12.2
        ports:
        - containerPort: 80

 

kubectl create -f deployment_nginx.yml
kubectl get pods -o wide 

We enter the node node to access these deployment

• Creating deploy the corresponding service

 

kubectl get deployment
expose deployment nginx-deployment
kubectl get svc

Modify the deployment of internal service

 

kubectl edit deployment nginx-deployment

PS: According to modify the contents of your file, it will automatically update, but did not change ip, this is the service of the powerful. But in its current form direct change deloyment files, not recommended because he is not a rollover, the next time that the next rollover.