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Re: armv7 vs buster sudo complains about hostname or something



On Friday 05 July 2019 08:27:50 Greg Wooledge wrote:

> On Fri, Jul 05, 2019 at 06:15:02AM -0400, Gene Heskett wrote:
> > 127.0.0.1	localhost
> > 192.168.71.1	router.coyote.den	router
> > 192.168.71.3    	coyote.coyote.den	coyote
> > 192.168.71.4	shop.coyote.den		shop
> > 192.168.71.5	lathe.coyote.den	lathe
> > 192.168.71.6	lappy.coyote.den	lappy
> > 192.168.71.7	sheldon.coyote.den	sheldon
> > 192.168.71.10	GO704.coyote.den	GO704
> > 192.168.71.12	picnic.coyote.den	picnc
> > 192.168.71.21	MFC.coyote.den		printer	scanner
> > 192.168.71.30	vna.coyote.den		vna
> >
> > ::1		localhost ip6-localhost ip6-loopback
> >
> > ff02::1		ip6-allnodes
> > ff02::2		ip6-allrouters
> >
> > #127.0.1.1	raspberrypi
>
> I don't know which machine this /etc/hosts is from, but see how the
> last line is commented out, and has the name "raspberrypi", which
> does not appear on any other line?
>
> If "raspberrypi" is supposed to be your machine's local hostname, then
> you should uncomment that line.  Or, if you prefer, add a line with
> the machine's proper IPv4 LAN address plus its local hostname.
>
It is in fact picnc. picnc.coyote.den TBE.

> The purpose of having your local hostname in /etc/hosts (with *any*
> valid address for it, even a loopback one like 127.0.1.1) is so that
> processes which try to look up the local hostname before DNS is
> working will get a valid response, and not freak out.
>
> Debian uses 127.0.1.1 for this by default, but encourages you to
> override this with a static LAN address, if your host has one.  If
> you don't have a static LAN address, then the default will work.
>
> Since you commented out the default (again, assuming this machine's
> local hostname is "raspberrypi"), any process that tries to look up
> your hostname in the absence of DNS will throw a fit, and I wouldn't
> care to predict the exact symptoms you'll see.  Among them may be
> processes dying immediately upon startup, processes hanging, processes
> assuming things about your local network numbering scheme, processes
> spewing error messages, and so on.
>
> sudo does a hostname lookup because, for some reason incomprehensible
> to mortal women and men, it has a "host" field on every configuration
> line. It seems that the intent is you'll write one gigantic-ass
> sudoers file with lines for every host on your network all mixed
> together, and drop a copy in /etc on every host; then, the "host"
> field on each line will tell each machine which lines to ignore.
>
> I don't know *anyone* who does it that way, and the documentation does
> not give any rationale for why sudoers has a "host" field, or what the
> intended use of this field is... so that's just my guess.

Its just as big a puzzle to me, but that rational does explain it.

> So anyway, because of this "feature" that absolutely nobody uses, sudo
> tries to look up your hostname, with multiple paths to failure if your
> hostname is not properly defined.


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>


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