The quotes around "host" for both `--pid` and `--net` were
causing trouble for me:
> docker: --pid: invalid PID mode.
and:
> docker: Error response from daemon: network "host" not found.
I've also changed the `-v` call to `--mount` for consistency with the
rest of the playbook.
Basic system stats, to show stuff the synapse metrics
can't show such as resource usage by bridges, etc
Seems to work fine as well.
This too has only been tested on debian amd64 so far
