First, docker setup files have a long way to go for ease in setup. I mean writing the files, not using them.
Second, the support provided with docker is less than acceptable. There is no "everybody gets one" rule with them. You must pay for support, i get that, but they haven't even updated their app to work with docker (Kitematic, a GUI they made for docker)... if they can't update for their own apps, I can't trust them to update meaningfully in general.
Third, the number of exploits that are found in docker make it not usable for my own purposes, other than testing, so I can't recommend it to anyone else. https://www.cvedetails.com/vulnerability-list/vendor_id-13534/product_id-28125/Docker-Docker.html
Fourth, persistence. I am not sure what the docker devs were thinking when they made the docker image reset itself on reboot... This never actually happened to me but it happened to enough people to be seen as a serious problem. Not only that they have convinced users that it's supposed to be that way.
Of course no application is flawless the problem really is in support. If I have an issue I want to be able to tell myself it will actually get fixed in a reasonable amount of time. A level of implicit trust. This I don't feel with docker, not yet. I am sure in time things will be different. They do have backing from names like NVIDIA.
Why include the files if i feel this way?
Many people kept asking about it, so I ended up trying it.. Only to find out Kitematic wasn't updated. I wanted to support Docker and use it for myself. I sort of still do because of how easy it is to use.
But since my attempt at supplying docker in Shinobi a few users have noticed my lack of knowledge when it comes to making these files. They have taken the liberty to either modify or entirely replace portions of the Docker files I included. Thus leaving Shinobi Developers with less knowledge as to how it works than previously.
I will keep docker under consideration because I still use docker myself for testing. It is remarkably easy to use (given the repo owner made a good image). When the Docker team moves things along i'll extend my hand in their favor.
What to do if you still want Docker
You have three options.
You can head on over to the community chat and see if anyone there knows a thing or two :) As the Docker files are now mostly a community effort.
You can use the the kitematic tag. It says that it is old but it updates to the latest master of the Pro repository on start.
Install an Ubuntu image from Dockerhub then follow the manual installation method. Please note that your installation may not operate as expected when the Ubuntu docker image restarts.