Entrypoint/exec fix suggested by @csmith, and some more metadata

Dockerfile

 
 # metadata
 LABEL maintainer="daniel@danieloaks.net"
+LABEL description="Oragono is a modern, experimental IRC server written in Go"
 
 # install latest updates and configure alpine
 RUN apk update
 COPY --from=build-env /go/src/github.com/oragono/oragono/oragono.motd /ircd/oragono.motd
 
 # launch
-CMD /ircd-bin/run.sh
+ENTRYPOINT ["/ircd-bin/run.sh"]
 
 # # uncomment to debug
 # RUN apk add --no-cache bash

run.sh

 fi
 
 # run!
-/ircd-bin/oragono run
+exec /ircd-bin/oragono run