添加sidecar容器并输出日志

news2024/11/18 13:43:23

添加一个sidecar容器(使用busybox 镜像)到已有的pod
11-factor-app中,确保sidecar容器能够输出/var/log/11-factor-app.log的信息,使用volume挂载/var/log目录,确保sidecar能访问11-factor-app.log
文件

# 准备工作 创建一个 pod 11-factor-app

apiVersion: v1
kind: Pod
metadata:
  name: 11-factor-app
spec:
  containers:
  - name: count
    image: busybox
    args: 
    - /bin/sh
    - -c
    - >
      i=0;
      while true;
      do
        echo "$i: $(date)" >> /var/log/11-factor-app.log;
      done      
    volumeMounts:
    - name: varlog
      mountPath: /var/log  
  volumes:
  - name: varlog
    emptyDir: {}

controlplane ~ ➜  kubectl apply -f 11-factor-app.yml 
pod/11-factor-app created
# 查看容器输出

controlplane ~ ➜  kubectl exec 11-factor-app -it -- tail -n 5 /var/log/11-factor-app.log
0: Sun Jul 28 14:33:01 UTC 2024
0: Sun Jul 28 14:33:01 UTC 2024
0: Sun Jul 28 14:33:01 UTC 2024
0: Sun Jul 28 14:33:01 UTC 2024
0: Sun Jul 28 14:33:01 UTC 2024

# 添加sidecar
apiVersion: v1
kind: Pod
metadata:
  name: 11-factor-app
spec:
  containers:
  - name: count
    image: busybox
    args: 
    - /bin/sh
    - -c
    - >
      i=0;
      while true;
      do
        echo "$i: $(date)" >> /var/log/11-factor-app.log;
      done      
    volumeMounts:
    - name: varlog
      mountPath: /var/log  
  - name: sidecar
    image: busybox
    args:
    - /bin/sh
    - -c
    - "tail -n+1 -f /var/log/11-factor-app.log"
    volumeMounts:
    - name: varlog
      mountPath: /var/log            
  volumes:
  - name: varlog
    emptyDir: {}

controlplane ~ ➜  kubectl replace -f 11-factor-app-sidecar.yml --force
pod "11-factor-app" deleted
pod/11-factor-app replaced

#查看sidecar是否能读取到日志 打印最近五条信息
controlplane ~ ➜  kubectl logs 11-factor-app sidecar --tail=5
0: Sun Jul 28 14:37:48 UTC 2024
0: Sun Jul 28 14:37:48 UTC 2024
0: Sun Jul 28 14:37:48 UTC 2024
0: Sun Jul 28 14:37:48 UTC 2024
0: Sun Jul 28 14:37:48 UTC 2024