Bug 250081

Summary:	no motd displayed after reboot when update_motd="NO"
Product:	Base System	Reporter:	guyyur
Component:	bin	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	New ---
Severity:	Affects Some People	CC:	emaste, grahamperrin, imp, nomoo, yvesguerin
Priority:	---	Keywords:	patch
Version:	CURRENT
Hardware:	Any
OS:	Any
URL:	https://reviews.freebsd.org/D26654

Description guyyur 2020-10-03 19:32:01 UTC

r350184 changed login(1) to read /var/run/motd.

As been noted in
https://lists.freebsd.org/pipermail/svn-src-head/2019-July/126776.html
there is a need to support displaying an immutable motd with specific exact text at login.

To keep motd immutable and prevent it being prepended with uname output,
update_motd needs to be set to "NO" in rc.conf to not generate /var/run/motd.
An immutable motd file can then can be created in /var/run
but if it is a tmpfs, the file will not survive a reboot.

https://reviews.freebsd.org/D26654
Phabricator review to change login(1) back to reading /etc/motd.
This allows using /etc/motd as a regular file when update_motd="NO".
update_motd="YES" causes /etc/motd to be created as a symbolic link to /var/run/motd so login(1) will still read it.

Comment 1 guyyur 2021-04-05 08:54:50 UTC

The problem also affects update_motd="NO" when not using tmpfs for /var/run.

cleanvar_enable="YES" by default and cleanvar scripts removes files under /var/run so if motd is created there manually it will be deleted after reboot.

Comment 2 yvesguerin 2022-02-19 17:39:59 UTC

login(1) must honor the variable from /etc/login.conf: welcome=FOLDER_TO/motd

/etc/rc.d/motd needs to update motd with kernel info if update_motd="YES" so /etc/rc.d/motd needs to read the /etc/login.conf and find the motd file and update it.  If the filesystem where the motd file is read-only, display a message to inform the user/sysadmin.