we're trying to get Let's Encrypt up and running inside kubernetes with kube-cert-manager.

When running kube-cert-managerthis function is called to monitor the dns propagation which checks if the ACME challenge is found inside the dns TXT record.
When this gets called this error gets logged.

 2016/09/05 12:52:47 monitorDNSProgragation error: lookup foo.bar.de on 10.71.240.10:53: no such host

10.71.240.10 is the DNS server used everywhere inside our kubernetes cluster. I can resolve foo.bar.de in every container (pod) inside the cluster using dig. This is also possible in the kube-cert-manger container.
It's just not possible with the kube-cert-manager binary.

kube-cert-manager uses github.com/miekg/dns. I've replaced the function linked above with stdlib net.LookupTXT(c.domain) which returns the same error.

Is this some Go bug?
Some known configuration error in google-container-engine?

If you need more information just ask.

Thanks.