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+---
+kep-number: 10
+title: Graduate CoreDNS to GA
+authors:
+  - "@johnbelamaric"
+  - "@rajansandeep"
+owning-sig: sig-network
+participating-sigs:
+  - sig-cluster-lifecycle
+reviewers:
+  - "@bowei"
+  - "@thockin"
+approvers:
+  - "@thockin"
+editor: "@rajansandeep"
+creation-date: 2018-03-21
+last-updated: 2018-05-18
+status: provisional
+see-also: https://github.com/kubernetes/community/pull/2167
+---
+ 
+# Graduate CoreDNS to GA
+
+## Table of Contents
+
+* [Summary](#summary)
+* [Motivation](#motivation)
+    * [Goals](#goals)
+    * [Non-Goals](#non-goals)
+* [Proposal](#proposal)
+    * [User Cases](#use-cases)
+* [Graduation Criteria](#graduation-criteria)
+* [Implementation History](#implementation-history)
+
+## Summary
+
+CoreDNS is sister CNCF project and is the successor to SkyDNS, on which kube-dns is based. It is a flexible, extensible
+authoritative DNS server and directly integrates with the Kubernetes API. It can serve as cluster DNS,
+complying with the [dns spec](https://git.k8s.io/dns/docs/specification.md). As an independent project,
+it is more actively developed than kube-dns and offers performance and functionality beyond what kube-dns has. For more details, see the [introductory presentation](https://docs.google.com/presentation/d/1v6Coq1JRlqZ8rQ6bv0Tg0usSictmnN9U80g8WKxiOjQ/edit#slide=id.g249092e088_0_181), or [coredns.io](https://coredns.io), or the [CNCF webinar](https://youtu.be/dz9S7R8r5gw).
+
+Currently, we are following the road-map defined [here](https://github.com/kubernetes/features/issues/427). CoreDNS is Beta in Kubernetes v1.10, which can be installed as an alternate to kube-dns.
+The purpose of this proposal is to graduate CoreDNS to GA.
+
+## Motivation
+
+* CoreDNS is more flexible and extensible than kube-dns. 
+* CoreDNS is easily extensible and maintainable using a plugin architecture.
+* CoreDNS has fewer moving parts than kube-dns, taking advantage of the plugin architecture, making it a single executable and single process.
+* It is written in Go, making it memory-safe (kube-dns includes dnsmasq which is not). 
+* CoreDNS has [better performance](https://github.com/kubernetes/community/pull/1100#issuecomment-337747482) than [kube-dns](https://github.com/kubernetes/community/pull/1100#issuecomment-338329100) in terms of greater QPS, lower latency, and lower memory consumption. 
+
+### Goals
+
+* Bump up CoreDNS to be GA.
+* Make CoreDNS available as an image in a Kubernetes repository (To Be Defined) and ensure a workflow/process to update the CoreDNS versions in the future.
+  May be deferred to [next KEP](https://github.com/kubernetes/community/pull/2167) if goal not achieved in time.
+* Provide a kube-dns to CoreDNS upgrade path with configuration translation in `kubeadm`.
+* Provide a CoreDNS to CoreDNS upgrade path in `kubeadm`.
+
+### Non-Goals
+
+* Translation of CoreDNS ConfigMap back to kube-dns (i.e., downgrade).
+* Translation configuration of kube-dns to equivalent CoreDNS that is defined outside of the kube-dns ConfigMap. For example, modifications to the manifest or `dnsmasq` configuration.
+* Fate of kube-dns in future releases, i.e. deprecation path.
+* Making [CoreDNS the default](https://github.com/kubernetes/community/pull/2167) in every installer.
+
+## Proposal
+
+The proposed solution is to enable the selection of CoreDNS as a GA cluster service discovery DNS for Kubernetes.
+Some of the most used deployment tools have been upgraded by the CoreDNS team, in cooperation of the owners of these tools, to be able to deploy CoreDNS:
+* kubeadm
+* kube-up
+* minikube
+* kops
+
+For other tools, each maintainer would have to add the upgrade to CoreDNS.
+
+### Use Cases
+
+* CoreDNS supports all functionality of kube-dns and also addresses [several use-cases kube-dns lacks](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/network/coredns.md#use-cases). Some of the Use Cases are as follows: 
+    * Supporting [Autopath](https://coredns.io/plugins/autopath/), which reduces the high query load caused by the long DNS search path in Kubernetes.
+    * Making an alias for an external name [#39792](https://github.com/kubernetes/kubernetes/issues/39792)
+    
+* By default, the user experience would be unchanged. For more advanced uses, existing users would need to modify the ConfigMap that contains the CoreDNS configuration file.
+* Since CoreDNS has more supporting features than kube-dns, there will be no path to retain the CoreDNS configuration in case a user wants to switch to kube-dns.
+
+#### Configuring CoreDNS
+
+The CoreDNS configuration file is called a `Corefile` and syntactically is the same as a [Caddyfile](https://caddyserver.com/docs/caddyfile). The file consists of multiple stanzas called _server blocks_.
+Each of these represents a set of zones for which that server block should respond, along with the list of plugins to apply to a given request. More details on this can be found in the 
+[Corefile Explained](https://coredns.io/2017/07/23/corefile-explained/) and [How Queries Are Processed](https://coredns.io/2017/06/08/how-queries-are-processed-in-coredns/) blog entries.
+
+The following can be expected when CoreDNS is graduated to GA.
+
+#### Kubeadm
+
+* The CoreDNS feature-gates flag will be marked as GA.
+* As Kubeadm maintainers chose to deploy CoreDNS as the default Cluster DNS for Kubernetes 1.11:
+    * CoreDNS will be installed by default in a fresh install of Kubernetes via kubeadm.
+    * For users upgrading Kubernetes via kubeadm, it will install CoreDNS by default whether the user had kube-dns or CoreDNS in a previous kubernetes version.
+    * In case a user wants to install kube-dns instead of CoreDNS, they have to set the feature-gate of CoreDNS to false. `--feature-gates=CoreDNS=false`
+* When choosing to install CoreDNS, the configmap of a previously installed kube-dns will be automatically translated to the equivalent CoreDNS configmap.
+
+#### Kube-up
+
+* CoreDNS will be installed when the environment variable `CLUSTER_DNS_CORE_DNS` is set to `true`. The default value is `false`.
+
+#### Minikube
+
+* CoreDNS to be an option in the add-on manager, with CoreDNS disabled by default.
+
+## Graduation Criteria
+
+* Verify that all e2e conformance and DNS related tests (xxx-kubernetes-e2e-gce, ci-kubernetes-e2e-gce-gci-ci-master and filtered by `--ginkgo.skip=\\[Slow\\]|\\[Serial\\]|\\[Disruptive\\]|\\[Flaky\\]|\\[Feature:.+\\]`) run successfully for CoreDNS.
+  None of the tests successful with Kube-DNS should be failing with CoreDNS.
+* Add CoreDNS as part of the e2e Kubernetes scale runs and ensure tests are not failing.
+* Extend [perf-tests](https://github.com/kubernetes/perf-tests/tree/master/dns) for CoreDNS.
+* Add a dedicated DNS related tests in e2e scalability test [Feature:performance].
+
+## Implementation History
+
+* 20170912 - [Feature proposal](https://github.com/kubernetes/features/issues/427) for CoreDNS to be implemented as the default DNS in Kubernetes.
+* 20171108 - Successfully released [CoreDNS as an Alpha feature-gate in Kubernetes v1.9](https://github.com/kubernetes/kubernetes/pull/52501).
+* 20180226 - CoreDNS graduation to Incubation in CNCF.
+* 20180305 - Support for Kube-dns configmap translation and move up [CoreDNS to Beta](https://github.com/kubernetes/kubernetes/pull/58828) for Kubernetes v1.10.