docker system df 

镜像占用了超过3.718GB磁盘空间。

docker system df  -v

• 1.images的SIZE是磁盘大小，SHARED SIZE，是共享大小，CONTAINERS是启动容器的个数，如果是0就代表是没有使用的镜像。

• 2.Containers的size是修改层大小。

• 3.volume 的SIZE是所占空间大小，像"Mounts": bind这种挂载空间是没有计算在内的

[root@node172 ~]# docker system df  --verbose
#镜像空间使用情况
Images space usage:

REPOSITORY                                           TAG                       IMAGE ID       CREATED         SIZE      SHARED SIZE   UNIQUE SIZE   CONTAINERS
registry.cn-shenzhen.aliyuncs.com/lolos/loloss       flask-demon               f4a0d136e2c6   3 weeks ago     120.3MB   5.613MB       114.7MB       3
ghcr.io/linkerd/controller                           edge-21.2.1               e1cdfb82032f   4 weeks ago     44MB      0B            44MB          0
ghcr.io/linkerd/proxy                                edge-21.2.1               49ce29cf9e64   4 weeks ago     114.6MB   69.24MB       45.34MB       0
registry.cn-shenzhen.aliyuncs.com/jbjb/alpine        simple-v01                652ba0e5f116   4 weeks ago     24.53MB   5.613MB       18.92MB       0
registry.cn-shenzhen.aliyuncs.com/jbjb/demons-d      productcatalogue8         ef9e688776d8   5 weeks ago     285.4MB   267.7MB       17.62MB       0
registry.cn-shenzhen.aliyuncs.com/jbjb/demons-d      stockmanager1             fc9138052165   5 weeks ago     311MB     267.7MB       43.31MB       0
registry.cn-shenzhen.aliyuncs.com/jbjb/demons-d      shopfront1                93b876a3b2d8   5 weeks ago     313.8MB   267.7MB       46.09MB       0
registry.cn-shenzhen.aliyuncs.com/jbjb/demons-d      productcatalogue7         0fca3532f297   5 weeks ago     285.4MB   267.7MB       17.62MB       0
feiyu563/prometheus-alert                            latest                    72af7e46fae0   6 weeks ago     38.24MB   5.577MB       32.66MB       0
grafana/grafana                                      latest                    13afb861111c   7 weeks ago     187.3MB   5.577MB       181.7MB       0

#容器空间使用情况
Containers space usage:

CONTAINER ID   IMAGE                                               COMMAND                  LOCAL VOLUMES   SIZE      CREATED          STATUS                        NAMES
9c5c77704f14   629df02b47c8                                        "/docker-entrypoint.…"   0               1.12kB    50 minutes ago   Up 50 minutes                 k8s_nginx_nginx-6b69f5bc8b-s7c6n_default_ff2d472b-19b8-4da2-a886-c37f1e816494_0
6f1a7b49bf7a   629df02b47c8                                        "/docker-entrypoint.…"   0               420MB     50 minutes ago   Up 50 minutes                 k8s_nginx_nginx-6b69f5bc8b-52rn8_default_6b3c4d0d-0aaa-4b1d-8c79-4ffb610f7985_0
f73844563277   629df02b47c8                                        "/docker-entrypoint.…"   0               1.12kB    50 minutes ago   Up 50 minutes                 k8s_nginx_nginx-6b69f5bc8b-8ps4l_default_8fddf18a-928a-4435-9bbc-bd8ef584446d_0
066e8e715441   629df02b47c8                                        "/docker-entrypoint.…"   0               1.12kB    50 minutes ago   Up 50 minutes                 k8s_nginx_nginx-6b69f5bc8b-kpgcj_default_
#本地卷使用情况
Local Volumes space usage:

VOLUME NAME   LINKS     SIZE

Build cache usage: 0B

CACHE ID   CACHE TYPE   SIZE      CREATED   LAST USED   USAGE     SHARED

查看完我们可以通过以下命令进行删除

1. 可以通过 Docker 内置的 CLI 指令docker system prune来进行自动空间清理

[root@c169 ~]# docker system prune --help

Usage:  docker system prune [OPTIONS]

Remove unused data

Options:
  -a, --all             Remove all unused images not just dangling ones
      --filter filter   Provide filter values (e.g. 'label=<key>=<value>')
  -f, --force           Do not prompt for confirmation
      --volumes         Prune volumes

2. docker system prune 自动清理说明：

该指令默认会清除所有如下资源：

• 已停止的容器（container）
• 未被任何容器所使用的卷（volume）
• 未被任何容器所关联的网络（network）
• 所有悬空镜像（image）。
• 该指令默认只会清除悬空镜像，未被使用的镜像不会被删除。添加-a 或 --all参数后，可以一并清除所有未使用的镜像和悬空镜像。
• 可以添加-f 或 --force参数用以忽略相关告警确认信息

• (温馨提示如果文件太多太大这条命令会卡住，建议做pod驱逐到其他节点再执行，或者使用脚本找到镜像规律逐个删除)

[root@dockercon ~]# docker system prune --all
WARNING! This will remove:
        - all stopped containers
        - all networks not used by at least one container
        - all images without at least one container associated to them
        - all build cache
Are you sure you want to continue? [y/N] y
Deleted Containers:
f095899e7343e160d5b32d0688a6561a1a7f6af91c42ffe966649240b58ca23f

Deleted Images:
untagged: busybox:latest
untagged: busybox@sha256:e3789c406237e25d6139035a17981be5f1ccdae9c392d1623a02d31621a12bcc
deleted: sha256:6ad733544a6317992a6fac4eb19fe1df577d4dec7529efec28a5bd0edad0fd30
deleted: sha256:0271b8eebde3fa9a6126b1f2335e170f902731ab4942f9f1914e77016540c7bb
untagged: kalilinux/kali-linux-docker:latest
untagged: kalilinux/kali-linux-docker@sha256:28ff9e4bf40f7399e0570394a2d3d388a7b60c748be1b0a180c14c87afad1968
deleted: sha256:c927a54ec8a46164d7046b2a6dc09b2fce52b3066317d50cf73d14fa9778ca48
deleted: sha256:244c1920ef0442167cdbd095e5d29813cb5be0b70cc116faf8d7e50074f6c446

3 可以另外打开一个终端，查看实时事件（例如容器创建，删除等均会实时显示）

[root@node172 ~]# docker system events
2021-03-06T18:00:19.843255544+08:00 image untag sha256:f1a77cb119f480351fb7bdfcfeca2bcff57334a5205d9c770a7d5bc396287742 (name=sha256:f1a77cb119f480351fb7bdfcfeca2bcff57334a5205d9c770a7d5bc396287742)
2021-03-06T18:00:21.506665154+08:00 image delete sha256:f1a77cb119f480351fb7bdfcfeca2bcff57334a5205d9c770a7d5bc396287742 (name=sha256:f1a77cb119f480351fb7bdfcfeca2bcff57334a5205d9c770a7d5bc396287742)

脚本删除方式如下

cat <<END> delel-image
#!/bin/bash
#删除过期镜像，保留最新5个版本

CDATE=`date '+%Y-%m-%d_%H:%M:%S'`

#######比如经常发版的关键字是"rabbitmq"
for service in `docker images | grep 'rabbitmq' | awk '{print $1}' |sort -u`
do
        for i in `docker images | grep $service | awk '{print $2}' | awk -F"-"  '{print $1}' | sort  -u`
        do
                banben=`docker images | grep $service | awk '{print $2}'`
                mem=`docker images | grep $service | awk '{print $2}'  |wc -l`
        done
        #echo $banben
        #echo $mem 
        if [[ $mem -gt 3 ]];then
                arr=(${banben// /})
                #保留同样类型的5个镜像
                for(( j=3;j<${#arr[@]};j++)) do
                        docker rmi $service:${arr[j]}
                        #echo $service:${arr[j]}
                        echo "docker rmi $service:${arr[j]}   执行时间:$CDATE" >> /home/log_delete_images.log
                done
        fi
done
END

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