Kubernetes ---- pod configuration container start command

One 、 Start command

1.1 Writing configuration files

establish pod_command.yaml file , And write the following , That is, after the container starts , towards 、opt/text.txt File write timestamp , Execute commands mainly through command Field in , The type is in list format

apiVersion: v1
kind: Namespace
metadata:
  name: dev

---

apiVersion: v1
kind: Pod
metadata:
  name: pod-command
  namespace: dev
  labels:
    user: redrose2100
spec:
  containers:
  - name: busybox
    image: busybox:1.30
    command: ["/bin/sh","-c","touch /tmp/hello.txt;while true;do /bin/echo $(date +%T) >> /tmp/hello.txt;sleep 3;done;"]

1.2 Create resources

Use the following command to create namespace and pod resources

[[email protected] pod]# kubectl apply -f pod_command.yaml
namespace/dev created
pod/pod-command created
[[email protected] pod]#

1.3 Enter the container to check the data

as follows , Enter the container , And look at /tmp/hello.txt The contents of the document , as follows , Indicates that the command has been executed successfully

[[email protected] pod]# kubectl get pod -n dev
NAME          READY   STATUS    RESTARTS   AGE
pod-command   1/1     Running   0          6s
[[email protected] pod]# kubectl exec pod-command -n dev -it -c busybox /bin/sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # tail -n 5 /tmp/hello.txt
15:13:58
15:14:01
15:14:04
15:14:07
15:14:10
/ #

1.4 About kubernetes in command and args Parameter description of ：

• If command and args Didn't write , Then use dockerfile Configuration in
• If command Yes , however args Not written , that dockerfile The default configuration is ignored , Execute the input command
• If command Not written , however args Yes , that dockerfile Configured in ENTRYPOINT Your orders will be executed , With the current args Parameters of
• If command and args It's all written , that dockerfile The configuration of is ignored , perform command On the additional args Parameters

1.5 Delete resources

Use the following command to delete the resource

[[email protected] pod]# kubectl delete -f pod_command.yaml
namespace "dev" deleted
pod "pod-command" deleted
[[email protected] pod]#