This problem occurred when I was trying to create my own dockerfile ready to execute build

Error response from daemon: failed to parse mydockerfile-centos: ENV must have two arguments

The question is shown in the figure. This question means  

  At this time, we found that our env must require two parameters. Let’s take a look at our screenshot

As shown in the figure, there is only one parameter in my env. At this time, I found that I forgot the space

Make the following modifications

Obviously, I changed the env parameter to two parameters

  In the newly built dockerfile we created ourselves

It’s a success!