Posted on June 19, 2017

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By John Belamaric  Email  Twitter  GitHub

On June 14, 2017, CoreDNS-008 released!

CoreDNS is a DNS server that chains middleware, where each middleware implements a DNS feature.

Release v008 has a lot of content, with new middleware and major features added to existing middleware.

Please note there is an incompatible change to the log directive – it now only logs to stdout and so only allows stdout as the file name (which of course may be omitted).

Core

• -log flag was changed into a boolean as all logging will be written to standard output.

Middleware

New

• hosts allows CoreDNS to read a /etc/hosts styled file and generate responses from that.
• debug can disable the panic/recover that is enabled by default. Mostly useful for testing/non-prod use cases to generate stack traces.

Updates

• chaos now returns the correct version.bind TXT record.
• kubernetes
  • Now returns a proper NS record for the cluster domain
  • Supports ExternalName services, which was an oversight in the 1.0.0 version of the Kubernetes dns spec
  • Now supports federation records
  • Has had some other bug fixes.
• file
  • Now supports DNAME RFC 6672
  • Refuse to load a zone without a SOA record.
• file, auto don’t reload a zone when the SOA’s serial hasn’t changed.
• secondary now behaves properly if queried before the zone has been transferred
• log, errors output everything to stdout and let journald or docker (or whatever) that care of further handling. This is backwards incompatible change wrt to the Corefile: log query.log will return an error.
• cache got a new cache implementation to be more scalable and a new prefetchoption for fetching records before the TTL expires.
• proxy does not use singleinflight anymore, removing a potential bottleneck on the single mutex in that implementation; it now forwards all queries it get to the upstream nameserver.

Contributors

The following people helped with getting this release done:

Chris Aniszczyk, Chris O’Haver, cricketliu, Eric Yan, John Belamaric, Jonas Östanbäck, Manuel Alejandro de Brito Fontes, Miek Gieben, Pat Moroney, Yong Tang

If you want to help, please check out one of the issues and start coding!

Community

You find CoreDNS’s community in the following places:

• Mailing list/group: coredns-discuss@googlegroups.com
• Slack: #coredns on https://slack.cncf.io
• Twitter: @corednsio
• Github: https://github.com/coredns/coredns

Originally posted on CoreDNS blog