Docker Haveged is a container as an entropy gathering service. Based on alpine linux instead of other bloated distros.
In case you need an entropy gathering service on your docker host but don't want to / can't install locally an entropy gathering service.
The service makes more sense on Cloud servers and more specifically on CoreOS servers where you cannot install locally services.
The purpose of the service is to make sure you have available entropy on your host. To check if you are running low:
cat /proc/sys/kernel/random/entropy_avail
If the number is below 1000 then it is probably depleted.
To run the container:
docker run --privileged -d hortonworks/haveged:1.1.0