Logspout.
docker build -t tldr/prometheus .
docker run -d --name prometheus -h prometheus --dns 172.17.0.1 -p 9090:9090 tldr/prometheus
Test run, dumps the content of the rendered file to standard output:
docker run -it --rm --name prometheus -h prometheus --dns 172.17.0.1 -p 9090:9090 tldr/prometheus -dry