make weavedns the name resolver for containers by default

[rade]

Right now, containers started with weave run only use weavedns for name resolution when the --with-dns option has been specified. We did that because weavedns used to lack some key features required to act as a nameserver in a fair few cases. That has changed now, and hence that choice should be inverted, i.e. we should have a --without-dns option, though, arguably, only after #382.

NB: we'd want to avoid an ordering dependency here; i.e. it should be possible to start containers with dns pointing at weavedns even when weave/weavedns isn't running.

[squaremo]

NB: we'd want to avoid an ordering dependency here; i.e. it should be possible to start containers with dns pointing at weavedns even when weave/weavedns isn't running.

One way to do that is to check whether it's running, and run it if not. Are there other ways?

[rade]

One way to do that is to check whether it's running, and run it if not.

We don't do that for weave.

Are there other ways?

I want to preserve what is possible now; there is nothing stopping you from weave run --with-dnsing a container when neither weave or weavedns are running.

[peterbourgon]

+1

[rade]

it should be possible to start containers with dns pointing at weavedns even when weave/weavedns isn't running.

While that is possible currently, doing so by default strikes me as dangerous; seems way to easy to accidentally start containers pointing at a non-existing (and never-to-exist) weavedns server.

So, how about the default behaviour is to point at weavedns if it is running. And have --with-dns and --without-dns options to override that choice.

The proxy's behaviour should be changed to match.

[inercia]

Should this issue be solved after #382? If so, I guess #382 should have the same milestone...

[rade]

Should this issue be solved after #382?

No.