There is an open bug in systemd [0] that creates a bad experience for LFS
users that do not create a static /etc/resolv.conf .  This bug prevented me
from using “wget” to download many BLFS packages. Here is a proposed
workaround for inclusion in the next LFS version.

When following LFS’ network configuration instructions [1], the user leaves
a blank /etc/resolv.conf .  systemd-resolved later makes this a symlink to
a file containing a “nameserver 127.0.0.53” entry, and runs a “stub
resolver” service listening at this local address. Programs that resolve
their own names (instead of using the getent or systemd-resolve utilities)
like “wget” or “dig”, then send requests to this stub nameserver.  However
the stub server has a bug, where its resolutions do not follow CNAMEs
through to A records (oddly “systemd-resolve” does not share this bug).

One workaround could be to instruct all LFS users to create a static
/etc/resolv.conf, which avoids use of the stub resolver . However then the
nameserver list is not automatically updated by DHCP. My suggested
workaround for users that want to use DHCP, is a change to the systemd
setup instructions [2].  Instead of pointing /etc/resolv.conf at the
“../lib/systemd/resolv.conf” file, later after first-boot do:

ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

There is more information on this in the  “/ETC/RESOLV.CONF” section of
“man systemd-resolved.service”. There is one downside I see to this
approach from the manpage - “it does not know a concept of per-interface
DNS servers and hence only contains system-wide DNS server definitions”
 (including all those discovered through DHCP).  However this seems better
for many LFS users than having many of their DNS resolution requests fail.

Regards,

-Eric S. Stone

[0] https://github.com/systemd/systemd/issues/3826

[1]
http://linuxfromscratch.org/lfs/view/stable-systemd/chapter07/network.html

[2]
http://linuxfromscratch.org/lfs/view/stable-systemd/chapter06/systemd.html
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