Localkube should vendor kube-dns instead of the current kube2sky solution

[luxas]

Ref: kubernetes/kubernetes#23930

[luxas]

kubernetes/kubernetes#23930 was merged :)
Let's update Godeps and write a new DNSServer

[dlorenc]

FYI I started updating godeps, but got blocked on a k8s.io/kubernetes appc/spec incompatibility. We'll need this PR to get merged before we can continue: appc/spec#607

[luxas]

Yes, I also started updating to head, and hit the same error.

[luxas]

I started to think if it's easier to deploy DNS as an addon instead of built-in in the binary...
That way we would be much more compatible with "real" solutions. Also, the new DNS solution uses dnsmasq for caching (I think), and it might be easier to just deploy them together as a Pod.

@dlorenc WDYT? Our localkube code would also get cleaner...

[dlorenc]

@luxas I'm concerned about the size of the image that people would have to pull. Any idea how large it is?

[luxas]

~50MB. That's quite much.
But anyway, I'm concerned about the dnsmasq dep... (Although it might be a soft dep)

[dlorenc]

I'm going to move this out of the milestone. We should come up with a plan here soon. Running as a pod might be the right approach.

[luxas]

I'm leaning against going with the "official" kube-dns solution.
Then we won't have any compability problems.

I've already added a flag, --enable-dns which you may just set to false when adding the manifest

[philips]

It would be nice to make the kube-dns container smaller or something. The problem I see with not using the normal add-on is it makes the minikube cluster "more special".

For example this debugging guide doesn't work: https://coreos.com/kubernetes/docs/latest/network-troubleshooting.html#first-stop-dns-debugging

[philips]

Thoughts @ethernetdan ?

[dlorenc]

+1 on switching to the standard DNS addon model.

[philips]

@dlorenc another datapoint is today during my k8s workshop at LinuxCon EU someone asked about how to replace the DNS implementation and I was using minikube so I had to say "On a normal k8s cluster you can do that, minikube is special"

[ethernetdan]

+1 for add-on - minikube should mirror best practices where possible

I was able to get the kube-dns executable down to 28mb from 42mb by omitting symbol and debug info with make kube-dns GOLDFLAGS="--s -w"