如何清理docker目錄

docker 目錄已經占滿系統盤，又不好遷移，問下有沒有快捷的解決方案，答案是有的。以下是我整理的經典案列，適合生產以及測試使用。編寫清理docker 日志腳本如下：

[root@www ~]# cat clean_docker_log_space.log 
#!/bin/bash
docker_log_files=$(find /var/lib/docker/containers/ -name '*-json.log')
docker_logs_size=$(find /var/lib/docker/containers/ -name '*-json.log' | xargs du -sc | tail -1 |awk '{print $1,"K"}')
free -h &&  sync && echo 1 > /proc/sys/vm/drop_caches   #釋放系統緩存

echo -e "\033[32mThe docker log total size is $docker_logs_size\033[0m"

for log in $docker_log_files
    do
    	echo "Now is cleaning docker log,docker core logs:$log"
        cat /dev/null > $log
        systemctl reload docker  #加載docker服務，不影響已經docker
    done 

free -h

運行結果如下：

[root@www ~]# ./clean_docker_log_space.log 
              total        used        free      shared  buff/cache   available
Mem:           976M        598M        112M        6.8M        264M        157M
Swap:          511M         66M        445M
The docker log total size is 80 K
Now is cleaning docker log,docker core logs:/var/lib/docker/containers/7538f077348e3c9722fb90ed4b0a5c3d60d72112e989526767c63d55f5a76f3e/7538f077348e3c9722fb90ed4b0a5c3d60d72112e989526767c63d55f5a76f3e-json.log
Now is cleaning docker log,docker core logs:/var/lib/docker/containers/235d20190027e757a203f1b4d4093335fb92ba515f7a501448c36c1332c622a2/235d20190027e757a203f1b4d4093335fb92ba515f7a501448c36c1332c622a2-json.log
Now is cleaning docker log,docker core logs:/var/lib/docker/containers/685a7af447ce884de1e9bbeb5d4ca0ca99860096f71c33b4f9a4d15a427c5e00/685a7af447ce884de1e9bbeb5d4ca0ca99860096f71c33b4f9a4d15a427c5e00-json.log
              total        used        free      shared  buff/cache   available
Mem:           976M        599M        176M        6.8M        200M        168M
Swap:          511M         66M        445M



[root@www ~]# find /var/lib/docker/containers/ -name '*-json.log' | xargs du -sc | tail -1 |awk '{print $1,"K"}'
0 K

建議把腳本加Linux 定時任務里面每周清理一次，這個就可以保證docker 不產生而外的日志文件。

生產環境如下所示

 df -TH    docker 使用系統磁盤的93% 

執行腳本 clean_docker_log_space.log ，執行清理腳本之后df -TH，docker 使用系統磁盤的43%  

docker部署建議

 最后建議大家在部署docker 的應用建議在docker自定義配置目錄 

#首先，掛載容量的磁盤，掛載目錄選擇/data
[root@www ~]# mkdir -p /data
#停止docker
[root@www ~]# systemctl stop docker

#將數據移到新目錄
[root@www ~]# mv  /var/lib/docker /data
#修改配置,增加 --graph /data
[root@www ~]# vim /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --graph /data 


[root@www ~]# systemctl daemon-reload
[root@www ~]# systemctl start docker 
[root@www ~]# systemctl enable docker.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.