[root@hdss7-200 volume]# vim /data/k8s-yaml/base_resource/volume/emptydir.yaml 
apiVersion: v1
kind: Pod
metadata: 
  name: pod-emptydir
  namespace: app
  labels:
    tier: volume
    role: empty-dir
spec:
  containers:
  - name: main-container
    image: harbor.od.com/public/busybox:v1.31.1
    volumeMounts:
    - name: web-root
      mountPath: /tmp
    command:
    - httpd
    args:
    - -f
    - -h 
    - "/tmp/"
  - name: sidecar-container
    image: harbor.od.com/public/centos:7
    volumeMounts:
    - name: web-root
      mountPath: /tmp
    command:
    - /bin/bash
    args:
    - -c
    - "while :;do date +'%F %T' > /tmp/index.html;sleep 1;done"
  volumes:
  - name: web-root
    emptyDir: {}

[root@hdss7-21 ~]# kubectl apply -f http://k8s-yaml.od.com/base_resource/volume/emptydir.yaml
[root@hdss7-21 ~]# kubectl get pod pod-emptydir -n app -o wide
NAME           READY   STATUS    RESTARTS   AGE   IP            NODE                NOMINATED NODE   READINESS GATES
pod-emptydir   2/2     Running   0          71s   172.7.22.11   hdss7-22.host.com   <none>           <none>
[root@hdss7-21 ~]# kubectl describe pod pod-emptydir -n app
Name:         pod-emptydir
Namespace:    app
...
Containers:
  main-container:
...
    Mounts:
      /tmp from web-root (rw)
...
  sidecar-container:
...
    Mounts:
      /tmp from web-root (rw)
...
Volumes:
  web-root:
    Type:       EmptyDir (a temporary directory that shares a pod's lifetime)
    Medium:     
    SizeLimit:  <unset>
[root@hdss7-21 ~]# while :;do curl -s 172.7.22.11;sleep 1;done
2020-01-26 12:31:09
2020-01-26 12:31:10
2020-01-26 12:31:11
2020-01-26 12:31:12