On Thu, Apr 16, 2020, at 9:26 AM, Florian Weimer wrote: > * 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 (mzerq...@0pointer.de) wrote: > >> > > >> >> On Mi, 15.04.20 15:50, Florian Weimer (fwei...@redhat.com) 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? >
Based on earlier replies in the thread, resolved will use the nameservers from the file. There's no mention of it disabling itself. V/r, James Cassell _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org 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@lists.fedoraproject.org
