问题：“dock日志提示下载成功，dock列表无该镜像，系统日志提示下载失败”

群晖系统中有一个名为DOCK的套件深受大家喜欢，大家在使用dock套件是常常会遇到“下载超时”、“下载失败”等问题。针对这个问题，网上已经有了很多的解决方案。

这里就dock日志提示添加成功，dock列表无该镜像，系统日志提示下载失败
在这里插入图片描述

的问题，为大家提供一个解决思路。

原因分析

这里猜测是群晖的doker套件内置组件出现了问题，后面解决方案应该是绕过了这个下载的bug，成功的下回了镜像。（不太懂哈，轻喷）

1. 使用Xshell进入群晖终端环境（linux）进行下载

首先下载一个xshell软件，版本xshell5或xshell6都可以，最好是xshell6。有的人使用putty，也是可以操作的。

开启SSH登录 ：打开群晖系统，进入“控制面板”→终端机和SNMP→打勾SSH，设置端口号，默认为22；这里我设置成
新建SSH会话 ：打开Xshell软件，新建会话属性，点击“连接”，输入主机(即群晖局域网ip：192.168.1.XXX)、端口号，点击“用户身份验证”，输入群晖管理员登录账号和密码；
登录群晖终端环境 ：点击会话下方“连接”按钮进入命令窗口，也可以点击“确认”保存到左侧，下次双击直接登录；登陆后提示提示如下


Connecting to <span class="token number">192.168</span><span class="token number">.1</span><span class="token punctuation">.</span><span class="token constant">XXX</span><span class="token punctuation">:</span>端口号<span class="token operator">...</span> Connection established<span class="token punctuation">.</span> To escape to local shell<span class="token punctuation">,</span> press <span class="token string">'Ctrl+Alt+]'</span><span class="token punctuation">.</span> admin@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span>$ 
Connecting to <span class="token number">192.168</span><span class="token number">.1</span><span class="token punctuation">.</span><span class="token constant">XXX</span><span class="token punctuation">:</span>端口号<span class="token operator">...</span> Connection established<span class="token punctuation">.</span> To escape to local shell<span class="token punctuation">,</span> press <span class="token string">'Ctrl+Alt+]'</span><span class="token punctuation">.</span> admin@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span>$ 
Connecting to 192.168.1.XXX:端口号... Connection established. To escape to local shell, press 'Ctrl+Alt+]'. admin@DiskStation:~$

获取高级权限 ：命令窗口中输入


 sudo <span class="token operator">-</span>i 
 sudo <span class="token operator">-</span>i 
 sudo -i

再次输入群晖管理员密码，


Password<span class="token punctuation">:</span> 
Password<span class="token punctuation">:</span> 
Password:

输入的密码不会显示出来，输完直接回车，输错了也直接回车，再输入“sudo -i”重新输入一遍；

查看已有镜像：这里介绍几个要用到的命令
docker images # 查看docker本地的镜像 docker search mysql # 搜索一个镜像，这里以搜索mysql为例 time docker pull nginx # 测试下载速度 docker pull mysql:5.7 # 下载mysql:5.7镜像 docker rmi XXXX # 删除镜像XXXX，这里XXX为镜像ID，输入docker images可查看已下载的镜像和对应的ID docker rmi $(docker images -q) # 删除全部镜像 synoservice --restart pkgctl-Docker # 重启docker
测试下载速度：这里我先使用了time docker pull nginx测试下载速度


root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># time docker pull nginx Using <span class="token keyword">default</span> tag<span class="token punctuation">:</span> latest latest<span class="token punctuation">:</span> Pulling <span class="token keyword">from</span> library<span class="token operator">/</span>nginx Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span><span class="token number">2539</span>d4344dd18e1df02be842ffc435f8e1f699cfc55516e2cf2cb16b7a9aea0b Status<span class="token punctuation">:</span> Image is up to date <span class="token keyword">for</span> nginx<span class="token punctuation">:</span>latest real <span class="token number">0</span>m6<span class="token punctuation">.</span><span class="token number">655</span>s user <span class="token number">0</span>m0<span class="token punctuation">.</span><span class="token number">061</span>s sys <span class="token number">0</span>m0<span class="token punctuation">.</span><span class="token number">011</span>s 
root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># time docker pull nginx Using <span class="token keyword">default</span> tag<span class="token punctuation">:</span> latest latest<span class="token punctuation">:</span> Pulling <span class="token keyword">from</span> library<span class="token operator">/</span>nginx Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span><span class="token number">2539</span>d4344dd18e1df02be842ffc435f8e1f699cfc55516e2cf2cb16b7a9aea0b Status<span class="token punctuation">:</span> Image is up to date <span class="token keyword">for</span> nginx<span class="token punctuation">:</span>latest real <span class="token number">0</span>m6<span class="token punctuation">.</span><span class="token number">655</span>s user <span class="token number">0</span>m0<span class="token punctuation">.</span><span class="token number">061</span>s sys <span class="token number">0</span>m0<span class="token punctuation">.</span><span class="token number">011</span>s 
root@DiskStation:~# time docker pull nginx Using default tag: latest latest: Pulling from library/nginx Digest: sha256:2539d4344dd18e1df02be842ffc435f8e1f699cfc55516e2cf2cb16b7a9aea0b Status: Image is up to date for nginx:latest real 0m6.655s user 0m0.061s sys 0m0.011s

切换了几个节点才开始下载：参考加速镜像节点链接如下

https://registry.docker-cn.com
http://hub-mirror.c.163.com
https://3laho3y3.mirror.aliyuncs.com
http://f1361db2.m.daocloud.io
https://mirror.ccs.tencentyun.com
如果下载速度很慢，切换上述几个地址，分别测试一下，哪个下载快，就用哪个下载。修改镜像加速的方法可参考简书.


 这里对于某些镜像选择`lastet版本`还是其他版本我暂时还不知道怎么弄，有知道的小伙伴可以在下方给我留言哦。 
 这里对于某些镜像选择`lastet版本`还是其他版本我暂时还不知道怎么弄，有知道的小伙伴可以在下方给我留言哦。 
 这里对于某些镜像选择`lastet版本`还是其他版本我暂时还不知道怎么弄，有知道的小伙伴可以在下方给我留言哦。

下载镜像 :这里以下载docker注册表中的oldiy/docker-webssh2为例


root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># docker pull oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 Using <span class="token keyword">default</span> tag<span class="token punctuation">:</span> latest latest<span class="token punctuation">:</span> Pulling <span class="token keyword">from</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 <span class="token number">88286</span>f41530e<span class="token punctuation">:</span> Pull complete d0e8a23136b3<span class="token punctuation">:</span> Pull complete <span class="token number">5</span>ad5b12a980e<span class="token punctuation">:</span> Pull complete <span class="token number">81</span>a43fd8c11b<span class="token punctuation">:</span> Pull complete Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span>f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status<span class="token punctuation">:</span> Downloaded newer image <span class="token keyword">for</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2<span class="token punctuation">:</span>latest 
root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># docker pull oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 Using <span class="token keyword">default</span> tag<span class="token punctuation">:</span> latest latest<span class="token punctuation">:</span> Pulling <span class="token keyword">from</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 <span class="token number">88286</span>f41530e<span class="token punctuation">:</span> Pull complete d0e8a23136b3<span class="token punctuation">:</span> Pull complete <span class="token number">5</span>ad5b12a980e<span class="token punctuation">:</span> Pull complete <span class="token number">81</span>a43fd8c11b<span class="token punctuation">:</span> Pull complete Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span>f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status<span class="token punctuation">:</span> Downloaded newer image <span class="token keyword">for</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2<span class="token punctuation">:</span>latest 
root@DiskStation:~# docker pull oldiy/docker-webssh2 Using default tag: latest latest: Pulling from oldiy/docker-webssh2 88286f41530e: Pull complete d0e8a23136b3: Pull complete 5ad5b12a980e: Pull complete 81a43fd8c11b: Pull complete Digest: sha256:f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status: Downloaded newer image for oldiy/docker-webssh2:latest

会有四个进度条同时下载，下载结束后会出现


Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span>f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status<span class="token punctuation">:</span> Downloaded newer image <span class="token keyword">for</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2<span class="token punctuation">:</span>latest 
Digest<span class="token punctuation">:</span> sha256<span class="token punctuation">:</span>f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status<span class="token punctuation">:</span> Downloaded newer image <span class="token keyword">for</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2<span class="token punctuation">:</span>latest 
Digest: sha256:f14e68f727fd9942f4fdbc02832c1910ee179ba20a99fc132a28e86583cc0e36 Status: Downloaded newer image for oldiy/docker-webssh2:latest

查看下载镜像 这样就下载完成了，再在命令行中输入docker images


root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># docker images <span class="token constant">REPOSITORY</span> <span class="token constant">TAG</span> <span class="token constant">IMAGE</span> <span class="token constant">ID</span> <span class="token constant">CREATED</span> <span class="token constant">SIZE</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 latest fd4b4b08d165 <span class="token number">12</span> months ago <span class="token number">127</span>MB 
root@DiskStation<span class="token punctuation">:</span><span class="token operator">~</span># docker images <span class="token constant">REPOSITORY</span> <span class="token constant">TAG</span> <span class="token constant">IMAGE</span> <span class="token constant">ID</span> <span class="token constant">CREATED</span> <span class="token constant">SIZE</span> oldiy<span class="token operator">/</span>docker<span class="token operator">-</span>webssh2 latest fd4b4b08d165 <span class="token number">12</span> months ago <span class="token number">127</span>MB 
root@DiskStation:~# docker images REPOSITORY TAG IMAGE ID CREATED SIZE oldiy/docker-webssh2 latest fd4b4b08d165 12 months ago 127MB