k8s volume storage volumes

Pod storage volume is a volume that can be shared directory access a plurality of containers, the volume Kubernetes concept, use and purpose of the docker volume relatively similar, but not both equivalent, firstly, the volume is defined Kubernetes on Pod, then a plurality of containers in the Pod hanging on to a specific file directory; Secondly, in the same volume and Pod kubenetes life cycle, but not with the life cycle of the container, when the container is terminated or restarted, the data volume of will not be lost, and finally Volume supports multiple data types, such as: GlusterFS, Ceph, etc. absorbed into the distributed file system

volume of use is relatively simple, in most cases, we first Volume in a Pod life, and then reference the Volume and mount it to a directory on the container in the container, for example, we define two in a Pod in container, a container run Nginx, a container run busybox, then we define a shared storage volume on the Pod, the contents inside the container should be able to see two, topology is as follows:

 

 

The following standard red to note that the name of the shared volume to be consistent

[root@master ~]# cat test.yaml 
apiVersion: v1
kind: Service
metadata:
  name: serivce-mynginx
  namespace: default
spec:
  type: NodePort
  selector:
    app: mynginx
  ports:
  - name: nginx
    port: 80
    targetPort: 80
    nodePort: 30080
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: deploy
  namespace: default
spec:
  replicas: 1
  selector: 
    matchLabels:
      app: mynginx
  template:
    metadata:
      labels:
        app: mynginx
    spec:
      containers:
      - name: mynginx
        image: lizhaoqwe/nginx:v1
        volumeMounts:
        - mountPath: /usr/share/nginx/html/
          name: share
        ports:
        - name: nginx
          containerPort: 80
      - name: busybox
        image: busybox
        command:
        - "/bin/sh"
        - "-c"
        - "sleep 4444"
        volumeMounts:
        - mountPath: /data/
          name: share
      volumes:
      - name: share
        emptyDir: {}

 

Create a Pod

[root@master ~]# kubectl create -f test.yaml

View Pod

[root@master ~]# kubectl get pods
NAME                      READY   STATUS    RESTARTS   AGE
deploy-5cd657dd46-sx287   2/2     Running   0          2m1s

View service

[root@master ~]# kubectl get svc
NAME              TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes        ClusterIP   10.96.0.1      <none>        443/TCP        6d10h
serivce-mynginx   NodePort    10.99.110.43   <none>        80:30080/TCP   2m27s

We busybox container into which create an index.html

[root@master ~]# kubectl exec -it deploy-5cd657dd46-sx287 -c busybox -- /bin/sh

容器内部：
/data # cd /data
/data # echo "fengzi" > index.html

Open a browser to test

 

 

Nginx seen to container if there is an index.html file

[root@master ~]# kubectl exec -it deploy-5cd657dd46-sx287 -c nginx -- /bin/sh  
容器内部：     
# cd /usr/share/nginx/html
# ls -ltr
total 4
-rw-r--r-- 1 root root 7 Sep  9 17:06 index.html

ok, our documentation is written in the busybox in nginx to read!