You want to get docker autocomplete in your terminal ? Here is what you can do
Tested Configuration:
MacOS: Sierra 10.12
Terminal: iTerm2 & Terminal

1. Open your terminal

Type sudo nano ~/.bash_profile
Write at the end of the file source ~/.docker-completion.bash
And save. (by hiting Ctrl + X then hit Y to confirm)

This part will automatically load the “docker autocompletion script” when your terminal starts.

2. Copy the script

Copy the content of this file (open the page and hit Ctrl + A, then Ctrl + C)
Type: sudo nano ~/.docker-completion.bash
Paste the content of the file inside ( Ctrl + V for instance)

Save like before

3. Restart your terminal

To quit Press Cmd + Q for instance (you must quit, not simply close) And open your terminal again !

Now you can write docker conta and press tab -> it will autocomplete into docker container and it will autocomplete with your container names etc…