我之前-一段时间之前-从Docker提取图像，但是现在看来情况已经改变。
以https://hub.docker.com/r/datagrip为例。文档指出安装如下
docker pull sath89/oracle-xe-11g
这不再适用于当前的Docker集线器。我可以尝试最新的
[myuser:~] $ docker pull sath89/oracle-xe-11g
Using default tag: latest
Error response from daemon: pull access denied for sath89/oracle-xe-11g, repository does not exist or may require 'docker login'
或标记11.2
[myuser:~] 1 $ docker pull sath89/oracle-xe-11g:11.2
Error response from daemon: pull access denied for sath89/oracle-xe-11g, repository does not exist or may require 'docker login'
我当然可以尝试登录-登录成功，但是提取图像仍然无法正常工作。
[myuser:~] 1 $ docker login
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: mydockerhubuser
Password:
WARNING! Your password will be stored unencrypted in /home/myuser/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store
Login Succeeded
[myuser:~] $ docker pull sath89/oracle-xe-11g:11.2
Error response from daemon: pull access denied for sath89/oracle-xe-11g, repository does not exist or may require 'docker login'
[myuser:~] 1 $
如今从Docker集线器中提取映像的秘密是什么？曾经如此简单。太容易了。