This helps large deployments which need to open up thousands of ports
(matrix_coturn_turn_udp_min_port, matrix_coturn_turn_udp_min_port)
On a test VM, opening 1k ports takes 17 seconds for Docker to "publish"
all of these ports (setting up forwarding rules with the firewall, etc),
so service startup and shutdown take a long amount of time.
If host-networking is used, there's no need to open any ports at all
and startup/shutdown can be quick.
- forego removing Docker images - it's not effective anyway, because it
only removes the last version.. which is a drop in the bucket, usually
- do not reload systemd - it's none of our business. `--tags=start`,
etc., handle this
- combine all uninstall tasks under a single block, which only runs if
we detect traces (a leftover systemd .service file) of the component.
If no such .service is detected, we skip them all. This may lead to
incorect cleanup in rare cases, but is good enough for the most part.
Slavi Pantaleev