[Swan-dev] test domain interface changes
andrew.cagney at gmail.com
Sun Sep 6 02:23:39 UTC 2020
There are two, related proposals. Lets go through each carefully.
First there's <swandefault>:
On Sat, 5 Sep 2020 at 19:47, Paul Wouters <paul at nohats.ca> wrote:
> On Fri, 4 Sep 2020, Andrew Cagney wrote:
> >>> this makes getting to the real domain and host much exier (OpenBSD
> >>> is already using swandefault when NFS mounting /testing)
> >> But then eth0 is never used in tests ?
> > OpenBSD is using its dedicated <swandefault> interface to directly NFS
> > mount /testing. It doesn't need nic. We think it will work when
> > there are multiple instances of obsde et.al.
> > I don't see why we shouldn't make this pervasive, and use <interface>0
> > so it is memorable.
> We removed the extra unused interfaces a few years ago that were in
> 126.96.36.199/24. Those were eth2 and could be used but never were. Except
> on nic where it can hook up to the real internet.
(Hm, what's 188.8.131.52/24? Perhaps you ment 184.108.40.206/24 which seems unused?
Based on the XML, OpenBSD's west has:
while linux's west has:
If we really are going to shoot for the holy grail where generic tests
work with arbitrary OSs on east/west then I think well be better off
having linux and bsd sharing a single machine definition. If nothing
else it would fix what looks like a bug in the above, but would mean
<swandefault> is present on linux systems.
This leads to the second reason for adding <swandefault>. Currently,
for east et.al. to get access to the real world it needs to go through
hoops. NIC needs to be up and re-configured; east's routing tables
need to be fixed, ... All secret sauce that no one can quite remember
how to get working. Having direct access to <swandefault> NAT should
simplify all that.
> >> But we want east and west with eth0 in the same network and with eth1 not on the same network ?
> > So don't enable the network. It's one thing to have the network
> > wired, another to have it enabled.
> I don't see the gain of breaking 700 test cases and their output just
> for using a different interface in openbsd. Just let openbsd use a
> new named interface ?
What we're talking about here is a _natted_ bridge that multiple
instances of obsde, say, can use to simultaneously access the host.
This means the VMs do not, and cannot, have pre-assigned ethernet / ip
addresses. And this is what <swandefault> provides.
> > east 192_0_2 192_1_2
> > nic 192_1_2 192_1_3 swandefault
> > north 192_0_3 192_1_3
> > openbsde 192_1_2 192_0_2 swandefault
> > openbsdw 192_1_2 192_0_1 swandefault
> > road 192_1_3
> > west 192_0_1 192_1_2
(this is the first time I've been able to reliably see how the
interfaces are laid out)
> > we could at least have east, west, and nic use the same interface for
> > 192_1_2, for instance:
> > 0: swandefault
> > 1: 192_1_2
> > 2: the other interface
> > 3: and more random interfaces
> But almost no test would use eth0. I'd rather stick to eth0 for machines
> with "one real" interface, like road and north, and eth0 and eth1 for
> west and east that have to have "two real" interfaces.
Now we get to renumbering/renaming. If you really think eth0 should
be a real interface, then <swandefault> can go last - knowing the last
interface is always the NAT is almost as easy as knowing it is the
(speaking of which, why do east and west - our most common test
exchange talk through the counter intuitive eth1 and not eth0?)
Two things to keep in mind:
- shuffling interfaces is incremental
one domain at a time (and personally I don't tend to push changes
affecting all test output without updating the output first)
- updating is transparent:
gmake kvm-clean kvm-install kvm-test
rebuilds all the test VMs and their interfaces already
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