zoneregistry

README

zoneregistry

A CoreDNS plugin to handle service discovery across distributed kubernetes clusters

TODOs

• Return A/AAAA instead of CNAMEs from the registry
• Loadbalance the peers records
• Add concurrency safety on the peers map
• Add CI + automated testing
• Add support for multiple zoneregistry masters
• Add e2e test for standalone deployment
• Add e2e test for k8s deployment
• Update README

Configure

Configuration options can be used to customize the behaviour of a plugin:

{
zoneregistry ZONE
    peers [PEERS...]
    interval INTERVAL
    ttl TTL
    fallthrough [ZONES...]
}

• peers the subzones to run healthchecks against.
• interval can be used to override the default INTERVAL value of 60 seconds.
• ttl can be used to override the default TTL value of 300 seconds.
• fallthrough if zone matches and no record can be generated, pass request to the next plugin. If [ZONES...] is omitted, then fallthrough happens for all zones for which the plugin is authoritative. If specific zones are listed (for example in-addr.arpa and ip6.arpa), then only queries for those zones will be subject to fallthrough.

Example

Configuring the zone registry to perform healthchecks on 3 k8s clusters

. {
  zoneregistry service.pinax.network {
    peers riv-prod1. riv-prod2. mar-prod3.
    interval 60
    ttl 300
  }
}

riv-prod1. {
  forward . 172.21.0.1:53
}

riv-prod2. {
  forward . 172.21.0.2:53
}

mar-prod3. {
  forward . 172.19.0.1:53
}

Documentation

Index

• type ZoneRegistry
  • func (zr *ZoneRegistry) HealthCheck()
  • func (zr *ZoneRegistry) Name() string
  • func (zr *ZoneRegistry) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)

Types

type ZoneRegistry

type ZoneRegistry struct {
	Next  plugin.Handler
	Zones []string
	Peers map[string]bool

	Fall fall.F
	// contains filtered or unexported fields
}

func (*ZoneRegistry) HealthCheck

func (zr *ZoneRegistry) HealthCheck()

func (*ZoneRegistry) Name

func (zr *ZoneRegistry) Name() string

func (*ZoneRegistry) ServeDNS

func (zr *ZoneRegistry) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)

ServeDNS implements the plugin.Handler interface.