Error in mon_candy

[dimanzt]

Hi,
I'm trying to use swarmprom with Openfaas (docker swarm). However I get the following error when trying to deploy it:

zadtoota@diman-z820:~/Desktop/Research/swarmprom$ docker stack deploy -c docker-compose.yml mon
Updating service mon_dockerd-exporter (id: 92o4qfucmjfu123fo266jhiaf)
Updating service mon_cadvisor (id: yplx9ugpe5kkl677q3l61g9q7)
Updating service mon_grafana (id: ibh1qawzpdzqqmdzizk5bwt5l)
Updating service mon_alertmanager (id: 97rdhg67u22iu0zqo0gz2owcl)
Updating service mon_unsee (id: gq8yi6wbd5942o1wwqps3cxtl)
Updating service mon_node-exporter (id: 9a148f1acoxtrk41htes3penx)
Updating service mon_prometheus (id: i7nopqesz5kpotedbl6m9muj5)
Creating service mon_caddy
failed to create service mon_caddy: Error response from daemon: rpc error: code = InvalidArgument desc = port '9090' is already in use by service 'func_prometheus' (1v22p2jvtv6t7beslcvl9366r) as an ingress port

Any idea how to solve this?