bin/57254: Enhancement to NetBSD /etc/rc.d/entropy

[lloyd%must-have-coffee.gen.nz@localhost]

>Number:         57254
>Category:       bin
>Synopsis:       Enhancement to NetBSD /etc/rc.d/entropy
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 02 20:05:00 +0000 2023
>Originator:     Lloyd Parkes
>Release:        10.0_BETA
>Organization:
Must Have Coffee
>Environment:
NetBSD ceph4.must-have-coffee.gen.nz 10.0_BETA NetBSD 10.0_BETA (GENERIC) #2: Wed Dec 21 12:02:20 NZDT 2022  lloyd%ceph4.must-have-coffee.gen.nz@localhost:/home/lloyd/NetBSD/objdir/sys/arch/amd64/compile/GENERIC amd64

>Description:
I like the work that has been done to the entropy system and I especially like usability improvements that have been made since I first saw the new entropy system. I can see one (rare) way that NetBSD users might find themselves without entropy and this minor enhancement to /etc/rc.d/entropy should catch it.

It would be good if this enhancement was applied to current and the 10 branch.

I have labelled this serious/medium because entropy makes some people angry and not because I think a lot of people will benefit from this enhancement directly.
>How-To-Repeat:
I have a habit of building new ways to build NetBSD images every few years and it occurred to me that people using custom images will bypass the entropy checks in the installer.

Someone installing an image that doesn't take care of the lack of entropy on older hardware will encounter unexpected application hangs, particularly in Python.
>Fix:
The patch at https://gist.github.com/lparkes/b082088e36c06c6dc0b27309431cf1bf alters to default behaviour of /etc/rc.d/entropy so that it complains loudly without interrupting multiuser boot.

The general behaviour of NetBSD is not changed, but now the sysadmin has messages in their logs telling them that something is wrong. /etc/rc.d/entropy with this patch will output an error message to the console and exit with status 1. This will cause /etc/rc.d/entropy to be listed as a failed service in /run/rc.log and on the console after the system has finished booting.

I don't know about other people who build images, but I always check the console and/or /run/rc.log when booting a new image.