An unofficial, unsupported and in no way connected to Microsoft container image for MS SQL Server
Resulting container images can be found at the Docker hub (MS SQL Developer Edition / MS SQL Express) Update: I was told by Microsoft that sharing the images on the Docker hub violates the EULA, so I had to remove them.
More background and instructions for usage in this blog post
I have forked this since my company want the image we use for builds and testing in Docker to be controlled by me. Nothing more than that, although it may get tweaked in future I suppose. I'll update here if that's the case!