Thanks! I really like those articles too. With this topic, I found many posts online just stated information about containers almost like they are trying to rewrite the documentation, which didn't seem like a good use of writing an article. This experimental process is what I went through to learn the content and I felt as though it would be helpful for others to go through it too.
The official documentation used that as an example, and because I wanted to steal their image, I did that too. Of course, please don't use Ubuntu 15.04 for containers you care about.