* Zbigniew Jędrzejewski-Szmek: > On Thu, Apr 16, 2020 at 12:53:48PM +0200, Florian Weimer wrote: >> * Lennart Poettering: >> >> > On Mi, 15.04.20 16:30, Lennart Poettering (mzerqung@xxxxxxxxxxx) wrote: >> > >> >> On Mi, 15.04.20 15:50, Florian Weimer (fweimer@xxxxxxxxxx) wrote: >> >> >> >> > * Lennart Poettering: >> >> > >> >> > > 1. If /etc/resolv.conf is a regular file, resolved will *consume* it >> >> > > for DNS configuration, and never change it or modify it or replace >> >> > > it. If this mode is selected arbitrary other programs that do DNS >> >> > > will talk directly to the provided DNS servers, and resolved is out >> >> > > of the loop. >> >> > >> >> > > In mode #1 resolved neither manages /etc/resolv.conf nor inserts >> >> > > itself into DNS resolution in any way. >> >> > >> >> > What will nss_resolve do in this case? Nothing? >> >> >> >> The nss_resolve module is just a wrapper around resolved's bus >> >> API. And the bus API uses resolved's own DNS resolution code. And >> >> resolved is smart enough to automatically become a *consumer* of >> >> /etc/nsswitch.conf (instead of a *manager* of it) if it is a regular >> >> file instead of a symlink to resolved's own files in /run. >> > >> > Meh. I mean /etc/resolv.conf here, of course, not /etc/nsswitch.conf. >> >> So if /etc/resolv.conf comes from somewhere else, then nss_resolve will >> still forward queries to the daemon, which contacts the upstream server >> on nss_resolve's behave (possibly with some caching), and eventually >> return the data to the application? > > nss-resolve is enabled/disabled through nsswitch.conf. It always talks to > systemd-resolved using local IPC. It doesn't care about /etc/resolv.conf > in any way. > > What Lennart wrote above applies to systemd-resolved and to things > which look at /etc/resolv.conf for some reason. If nss-resolve is enabled, > then only things which do not use nss at all would fall into this category. > >> Or does nss_resolve fail with UNAVAIL and expects nss_dns to fetch the >> data? > > nss_resolve fails with UNAVAIL when systemd-resolved is not running. > So yeah, we use want to use nss_dns as a fallback for that case. I'm not > sure if that is what you are asking about. Let me rephrase: If /etc/resolv.conf is a regular file, will systemd-resolved deactivate itself? Or use the name server configuration found there instead? Thanks, Florian _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
