go: net: go 1.11 DNS client incompatible with SRV records from kube-dns

What version of Go are you using (`go version`)?

go1.11

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (`go env`)?

linux amd64

What did you do?

Running the following application in Kubernetes exits with an error:

https://play.golang.org/p/EW5NVeHJMrV

What did you expect to see?

Expected to get SRV records back

What did you see instead?

When running in Kubernetes with kube-dns 1.14.10 the application exits with error: “cannot unmarshal DNS message” (underlying error is “Target: compressed name in SRV resource data”)

https://play.golang.org/p/EW5NVeHJMrV

A pcap of the DNS request: https://github.com/jnewmano/kube-dns/blob/master/dns_111_2.pcap

When built with Go1.10, it behaves as expected.

Golang-nuts discussion https://groups.google.com/forum/#!searchin/golang-nuts/dns|sort:date/golang-nuts/vAbjprJNPV0/HSh9635hBQAJ

About this issue

Original URL
State: closed
Created 6 years ago
Reactions: 3
Comments: 16 (9 by maintainers)

Most upvoted comments

I also think behavioral difference with dig should be taken into account

strk on Sep 24, 2019

For what it’s worth, the reason I requested to file this issue is that I guess this could be a roadblock for operating DNS-SD in near future. Nowadays DNS-SD is becoming important not only for consumer plug-and-pray-or-play use but for label distribution over unicast DNS with k8s-like scheduler stuff. As described in RFC 8222, we still don’t see the end of the label handling conflict between classical/conventional unicast DNS, and latest unicast and/or multicast DNS and DNS-SD, but need to find out a comprimise for both use cases.

One easy option would be just adding a control knob to net.Resolver and x/net/dnsmessge package without changing the current defaut, classical/conventional unicast DNS, behavior in the net package of standard library (see also #24870).

mikioh on Sep 20, 2018