zoneregistry

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 e2e test for standalone deployment
• Add primary/secondary role for peers
• Add prometheus metrics integration
• Add CI + automated testing
• Add support for multiple zoneregistry masters
• 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 {
    debug
    metrics
    interval 60
    timeout 10
    ttl 300

    peer riv-prod1.service.pinax.network {
        role primary
        labels cluster-env=prod
        IPv4 172.100.0.101
        IPv6 2001:db8:172:100::101
        protocol http
        path /health
        port 8080
    }
    peer riv-prod2.service.pinax.network {
        role primary
        labels cluster-env=prod
        IPv4 172.100.0.102
        IPv6 2001:db8:172:100::102
        protocol http
        path /health
        port 8080
    }
    peer mar-dev1.service.pinax.network {
        role secondary
        labels cluster-env=dev
        IPv4 172.100.0.1043
        IPv6 2001:db8:172:100::103
        protocol http
        path /health
        port 8080
    }
  }
}