K8s pod cluster of several access mode

k8s access pod and service are the following ways

host network

hostPort

NodePort

LoadBalancer

Ingress

hostNetwork host network mode corresponds docker run --net = host 

Example shows 

apiVersion: v1
kind: Pod
metadata:
  name: nginx-host
spec:
  hostNetwork: true
  containers:
    - name: nginx-host
      image: nginx

 kubectl create -f hostNetwork.yaml

See the pod is ip ip Node node, select such a network scheduling mode pod, pod vary depending on the selected nodes Node ip, port port, with the port needs to remain on the host port conflict.

hostport mode 

hostPort port is directly routed to a port on the container scheduled node, so that users can add Pod access by the host IP

Example shows

apiVersion: v1
kind: Pod
metadata:
  name: nginx-port
spec:
  hostNetwork: true
  containers:
    - name: nginx-host
      image: nginx
      ports: 
        - containerPort: 80
          hostPort: 80

kubectl create -f hostPort.yaml

curl 192.168.222.250:80/index.html

pod different nodes are scheduled, ip will change, you need to maintain a correspondence between the pod and the host

NodePort mode

NodePort default mode k8s service using cluster IP way, this service will produce a Cluster IP model, the cluster ip default can only be accessed within the cluster, you want direct access to the service outside, the type of service type needs to be modified to nodePort mode, nodePort value, the range 30000-32767

Examples are as follows

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    name: nginx
spec:
  containers:
    - name: nginx
      image: nginx
      ports:
        - containerPort: 80
---
kind: Service
apiVersion: v1
metadata:
  name: nginx
spec:
  type: NodePort
  ports: 
    - port: 80
      nodePort: 30008  #  nodePort值，范围是30000-32767
  selector:
    name: nginx

kubectl apply  -f Node_pod.yaml

Three ways to access the pod

Cluster internal access

pod ip  ：curl 10.244.1.245

ClusterIP ：curl 10.1.250.193

External Access cluster

NodePort： master：

http://192.168.222.240:30008  # NodePort mode will use to open a port on the master node and nodes, using multiple modes NodePort need to maintain a good correspondence between the port, the port to prevent conflict

LoadBalancer required to support the load balancer, the general cloud service providers have provided