Hah, I wrote something very, very similar to this recently. The problem I eventually had with it was that lsof wasn't always installed on the hosts I was working with. So, it turned into a script to parse through /proc and other nonsense.
systemd-analyze(1) supports dot(1) output to plot dependencies between units:
Quoting from the man page:
EXAMPLES FOR DOT
Example 1. Plots all dependencies of any unit whose name starts with "avahi-daemon"
$ systemd-analyze dot 'avahi-daemon.*' | dot -Tsvg > avahi.svg
$ eog avahi.svg
Example 2. Plots the dependencies between all known target units
systemd-analyze dot --to-pattern='*.target' --from-pattern='*.target' | dot -Tsvg > targets.svg
$ eog targets.svg
I might be missing something here, but shouldn't the graph be directed (processes opening fifos in read-only mode, or even unidirectional pipes like on Linux)? Or is it something impossible to query with lsof?
It otherwise is a very neat graphical overview of the state of a system!
Slide 12 here[1] shows that lsof distinguishes the read and write ends of FIFOs at least. For TCP I suppose I makes sense to check which end uses ephemeral port.