The haveged service file in Debian Buster specifies that haveged should
start after systemd-random-seed starts (this was removed in Bullseye
after systemd changes caused a bootloop). This is a bit
counterproductive, since haveged is meant to be used in environments
with minimal sources of entropy, but one of the checks that
systemd-random-seed does is to verify that entropy is present.
Therefore, override the default .service file for haveged that moves
systemd-random-seed to the Before list, allowing it to start before
systemd-random-seed checks the system entropy level. (systemd doesn't
allow removing items from dependency/ordering entries such as After= and
Before=, so the entire .service file has to be overwritten.)
Note that despite this, haveged takes up to two seconds to actually
start working, so systemd-random-seed may still block for about two
seconds. However, this still allows other work (such as running
rc.local) to proceed a bit sooner.
Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>
