Re: [PATCH v2 07/10] conf: Don't exit if sourced default route has no gateway

On Mon, 22 May 2023 18:48:39 +1000
David Gibson <david(a)gibson.dropbear.id.au> wrote:

...
  On Mon, May 22, 2023 at 01:42:21AM +0200, Stefano
Brivio wrote:
  If we use a template interface without a gateway
on the default
 route, we can still offer almost complete functionality, except that,
 of course, we can't map the gateway address to the outer namespace or
 host, and that we have no obvious server address or identifier for
 use in DHCP's siaddr and option 54 (Server identifier, mandatory).
 
 Continue, if we have a default route but no default gateway, and
 imply --no-map-gw and --no-dhcp in that case. NDP responder and
 DHCPv6 should be able to work as usual because we require a
 link-local address to be present, and we'll fall back to that.   
 
 Implying (rather than requiring) --no-map-gw and --no-dhcp does worry
 me a bit.  I feel like it might violate the principle of least
 surprise. 
Well, yes, but on the other hand it risks to be a lot of typing (and
changes to the Podman integration) for a relatively common setup. And
we might even figure out there's a way and a benefit to re-enable DHCP
support in this case.

I'm not fond of that either, but I still prefer it to the alternative.

-- 
Stefano