Gladder is a very basic Go (aka Baduk, WeiQi) Ranking site that you can use with your friends or go club. It is currently incomplete -- you can add players and set their rank, and it can calculate a handicap, but after a match you must manually change the two players' rankings.
The source code is located here: https://github.com/asokoloski/gladder
Gladder is written in the Go programming language (what else?) and uses https://github.com/steveyen/gkvlite for persistence.
How to use this image
With an arbitary port
> docker run -name gladder -d -v /LOCAL/DATA/PATH:/data -P asokoloski/gladder > docker port gladder 80 0.0.0.0:49165
Then take the port printed by the second command (49165) and go to localhost:49165 in your browser.
With a specific local port (8080, in this case)
> docker run --name gladder -d -v /LOCAL/DATA/PATH:/data -p 8080:80 asokoloski/gladder
The user database will be stored in a file in /LOCAL/DATA/PATH.
Finally, go to localhost:8080 in your browser to use Gladder.