On 05/24/2016 02:20 PM, Chuck Lever wrote: >>> $ nfsidmap --txt >>> >> >>> >> could retrieve it and display it, >>> >> >>> >> # nfsidmap --txt -s >>> >> >>> >> could retrieve it and update idmapd.conf if >>> >> there was a TXT record retrieved, for example. >> > I see what you are trying to do here... instead >> > of rewriting idmapd.conf... we should probably >> > uses... the system that shall go nameless... systemd! ;-) >> > >> > systemd could run the nfsidmap --txt command that would >> > create a file under /run, which is managed by the >> > systemd-tmpfiles package. rpcbind does something similar >> > to manage its warmstart up files. >> > >> > Then we could point rpc.idmap and nfsidmap to that >> > runtime file via the libnfsidmap interfaces. > Or provide a setting in /etc/idmapd.conf which is > the pathname of the /run file. > > It's a little nicer if these settings were all in > one place instead of split between /etc/sysconfig, > systemd configuration, and idmapd.conf.hostnamectl I agree... but... we are dealing with systemd which limits your options when it comes to reading in configuration files. > > No Domain= setting means: > 1. use the contents of the /run file > 2. if no /run file exists, or it's empty, use the > current mechanism to determine the ID mapping > domain name Right... but changing the name of the /run file really does not have to changeable, IMHO... > > How does hostnamectl work? does it use /run files? Taking a quick look it appears not to... I see a lot of dbus code... It does not look too interesting to me. > > >> > The problem with this is how do we expire this cache? >> > We would have to store the TTL to know when its time >> > to ping DNS again... Is the TTL returned in the DNS >> > query? > I'm not aware of any required caching semantics > (again, no real standard here). > > I wouldn't expect this setting to change very > often. Perhaps once per boot, or once per system > wake-up, or whenever there is a network configuration > change, is good enough. My guess is you don't want > this changing arbitrarily with running users on > the system. So maybe once per boot is the right > answer. Fine... we can deal with expiring the cache if it becomes an issue... > > "nfsidmap --txt -s" could force a refresh by hand. True. > > (Also we need to figure out how to break a tie > on multi-homed systems where more than one TXT > record is found; maybe the only thing to do in > that case is use Domain= , but you'd kind of > prefer good behavior without needing a manual > setting). Does that even work? How can you have multiple domains on the same host? I would say we document the fact the first TXT record processed is the one we go with. All others are ignored. steved. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
