Copy your hieradata to data/hieradata. Set your host pattern and hierarchy in conf/hieraexplorer.yaml
docker build -t hieraexplorer https://github.com/grimmsen/hieraexplorer.git
docker run -d -p 8080:8080 hieraexplorer
or
docker run -d -p 8080:8080 -v "$PWD/data:/data" -v $PWD/conf/hieraexplorer.yaml:/usr/src/app/conf/hieraexplorer.yaml hieraexplorer