diff --git a/proposals/coredns.adoc b/proposals/coredns.adoc index 843ba5a..8048af3 100644 --- a/proposals/coredns.adoc +++ b/proposals/coredns.adoc @@ -4,8 +4,8 @@ *Description* -CoreDNS is a fast, flexible DNS server that is designed to be performant with a flexible implementation. This flexibility 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. SkyDNS is a DNS server that has etcd as the datastore backend. It is widely +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 (https://github.com/skynetservices/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 @@ -32,23 +32,22 @@ used in cloud deployments, but lacks the flexibility we envision for CoreDNS. *Website*: https://coredns.io -*Release methodology and mechanics*: github master. As as young project no method for official releases has been -established. The current rule is: the master branch is production ready at all times. A more formal release -process is on its way, the choice to use semver versioning has not yet been made. Precompiled binaries will be -created by hooking into Caddy's website: https://caddyservers.com where "DNS" will be a download option. +*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 (https://caddyserver.com/download), where "DNS" will be a Server Type option. *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 following 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 user of SkyDNS to embrace -CoreDNS. +*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: +CoreDNS depends on Caddy (https://caddyserver.com/). Caddy is a framework that CoreDNS uses in two ways: 1. much of the CoreDNS code plugs into the framework to add DNS behavior. 2. CoreDNS provides a wrapper around the framework to provide a DNS-tuned command-line interface. @@ -76,25 +75,25 @@ Go dependencies: * Go package: golang/x/sys (BSD https://github.com/golang/sys/blob/master/LICENSE) * Go package: natefinch/lumberjack.v2 (MIT https://github.com/natefinch/lumberjack/blob/v2.0/LICENSE) * Go package: square/go-jose.v1 (ASLv2 https://github.com/square/go-jose/blob/master/LICENSE) -* Kubernetes (for CoreDNS -> kubernetes integration) (ASLv2 https://github.com/kubernetes/kubernetes/blob/master/LICENSE) +* Kubernetes (for CoreDNS -> Kubernetes integration) (ASLv2 https://github.com/kubernetes/kubernetes/blob/master/LICENSE) *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 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: +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 only requires 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 monitoring. +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 monitoring. -CoreDNS provides a cleaner, more extensible codebase as compared to SkyDNS. (Both SkyDNS and CoreDNS were authored by Miek Gieben.) +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. +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. +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.