Re: [VOTE] CoreDNS Project Proposal

Solomon Hykes <solomon.hykes@...>


On Thu, Aug 25, 2016 at 2:37 AM, Jonathan Boulle via cncf-toc
<cncf-toc@...> wrote:
Fellow TOC members:

The CoreDNS team has iterated on their project proposal to a final version
after feedback and it's now time to vote.

Proposal is available here and also embedded below.

To kick things off, here's my +1.



Name of project: CoreDNS


CoreDNS is a fast, flexible and modern DNS server. Its performant and
flexible implementation allows CoreDNS to be easily extended to support
various data sources and to implement rich DNS service behaviors: for
example, response caching, query rewrite, load-balancing, zone transfer and
signing. CoreDNS is the successor of SkyDNS
(, a DNS server that uses etcd as
its datastore backend. SkyDNS is widely used in cloud deployments, but lacks
the flexibility we envision for CoreDNS.

Sponsor / Advisor from TOC: Jonathan Boulle

Unique Identifier: coredns

License: Apache License v2.0

Source control repositories:

Initial Committers:

Miek Gieben github: miekg

Michael Richmond github: mrichmon

github: splack

Felix Cantournet github: fcantournet

github: leelynne

Matt Layher github: mdlayher

Vasily Vailyev github: pixelbender

Infrastructure requirements (CI / CNCF Cluster): N/A

Issue tracker:


Release methodology and mechanics: As a young project, no method for
official releases has been established, and no official releases have been
made; the current rule is that the master branch is production-ready at all
times. A more formal release process is on its way, and may introduce
semantic versioning, but a final decision has not yet been made. Precompiled
binaries will be distributed by hooking into Caddy’s download website
(, where "DNS" will be a Server Type

Social media accounts: Twitter: @corednsio

Existing sponsorship: Infoblox contributing developer time to implement
CoreDNS→Kubernetes integration component.

Existing community: The community is small, but growing. Current number of
Twitter followers is 100+ (after a week of having the Twitter account). By
aligning ourselves with the Caddy community, we hope to leverage Caddy’s
popularity for CoreDNS. By positioning CoreDNS as a better SkyDNS, we hope
to entice existing users of SkyDNS to migrate to and embrace CoreDNS.

External Dependencies

CoreDNS depends on Caddy ( Caddy is a framework
that CoreDNS uses in two ways:

much of the CoreDNS code plugs into the framework to add DNS behavior.

CoreDNS provides a wrapper around the framework to provide a DNS-tuned
command-line interface.

Go dependencies:

Go package: mholt/caddy (ASLV2

Go package: beorn7/perks (MIT

Go package: coreos/etcd (ASLv2

Go package: flynn/go-shlex (ASLv2

Go package: fsnotify/fsnotify (BSD

Go package: golang/protobuf (BSD

Go package: hashicorp/go-syslog (MIT

Go package: matttproud/golang_protobuf_extensions

Go package: miekg/dns (BSD

Go package: patrickmn/go-cache (MIT

Go package: prometheus/client_golang

Go package: prometheus/client_model

Go package: prometheus/common (ASLv2

Go package: prometheus/procfs (ASLv2

Go package: ugorji/go (MIT

Go package: xenolf/lego (MIT

Go package: golang/x/crypto (BSD

Go package: golang/x/net (BSD

Go package: golang/x/sys (BSD

Go package: natefinch/lumberjack.v2 (MIT

Go package: square/go-jose.v1 (ASLv2

Kubernetes (for CoreDNS → Kubernetes integration)

Statement on alignment with CNCF mission:

CoreDNS is a focused, lightweight DNS server. A microservice philosophy
guides the internal design of CoreDNS. Individual DNS functions are provided
by discrete, composable plugins that are enabled via runtime configuration.
CoreDNS can be thought of as a DNS protocol head that can be configured to
front various backend data sources. A flexible DNS server is a necessary
component to provide “Naming and Discovery” services to containers running
in the CNCF distributed system services environment.

Comparison with KubeDNS:

The incumbent DNS service for Kubernetes, “kubedns”, consists of four
components: * etcd provides a DNS data cache, * kube2sky provides the
mechanism for updating the etcd data cache, * skydns provides the DNS
service based on the data cached in etcd, * exechealthz provides
health-check status.

Running CoreDNS with Kubernetes requires only the coredns component. CoreDNS
does not require a separate data cache or update service. CoreDNS includes
an optional health-check “middleware” component that can be used for service

CoreDNS provides a cleaner, more extensible codebase as compared to SkyDNS.
(Both SkyDNS and CoreDNS were authored primarily by Miek Gieben.)

CoreDNS is currently being extended to operate directly with Kubernetes to
access the service data. This “middleware” implementation for CoreDNS
provides the same client-facing behavior as KubeDNS. The pipeline-based
design of CoreDNS allows easy extension to use any container orchestrator as
a DNS data source.

With the Kubernetes middleware, CoreDNS can be considered as an alternative
to SkyDNS with lower runtime complexity. Performance testing to compare
against SkyDNS is pending.

cncf-toc mailing list

Join to automatically receive all group messages.