Support IPv6

[duylong]

Hi,

I tried a deployment, everything is going well but I have the message "Nothing to show". I activated debug mode and I notice this behavior on the weave scope agents:

<probe> DEBU: 2020/03/23 13:46:20.521538 background /proc reader: full pass took 5.764523576s
<probe> DEBU: 2020/03/23 13:46:20.521590 background /proc reader: new rate limit period 500ms
<probe> DEBU: 2020/03/23 13:46:20.870727 DNSSnooper: caught DNS lookup: XXX -> map[192.168.X.X:{}]
<probe> DEBU: 2020/03/23 13:46:20.870811 DNSSnooper: caught DNS lookup: XXX -> map[192.168.X.X:{}]
<probe> DEBU: 2020/03/23 13:46:20.870832 DNSSnooper: caught DNS lookup: XXX -> map[192.168.X.X:{}]
<probe> DEBU: 2020/03/23 13:46:21.054612 DNSSnooper: caught DNS lookup: weave-scope-app.weave.svc.cluster.local -> map[]
<probe> DEBU: 2020/03/23 13:46:21.054704 DNSSnooper: caught DNS lookup: weave-scope-app.weave.svc.cluster.local -> map[]
<probe> DEBU: 2020/03/23 13:46:21.054737 DNSSnooper: caught DNS lookup: weave-scope-app.weave.svc.cluster.local -> map[]

In a container,

host weave-scope-app.weave.svc.cluster.local
weave-scope-app.weave.svc.cluster.local has IPv6 address fd00:10:96::XX

Does Weave Scope work with a Kubernetes cluster in IPv6?

[bboreham]

I'm pretty sure it needs some work to handle IPv6. The code that interprets network connections is hard-coded for IPv4 in places, e.g. https://github.com/weaveworks/scope/blob/7c838affaaa0ca12f8510c2d28f1e1853fa85d2e/probe/endpoint/four_tuple.go#L14