CoreDNS¶
Specific service annotation options¶
Groups¶
Groups can be used to group set of services together. The main use of this is to limit recursion,
i.e. don’t return all records, but only a subset. Let’s say we have a configuration like this:
---
apiVersion: v1
kind: Service
metadata:
name: a
annotations:
external-dns.alpha.kubernetes.io/hostname: a.domain.local
external-dns.alpha.kubernetes.io/coredns-group: "g1"
spec:
type: LoadBalancer
status:
loadBalancer:
ingress:
- ip: 127.0.0.1
---
apiVersion: v1
kind: Service
metadata:
name: b
annotations:
external-dns.alpha.kubernetes.io/hostname: b.domain.local
external-dns.alpha.kubernetes.io/coredns-group: "g1"
spec:
type: LoadBalancer
status:
loadBalancer:
ingress:
- ip: 127.0.0.2
---
apiVersion: v1
kind: Service
metadata:
name: c
annotations:
external-dns.alpha.kubernetes.io/hostname: c.subdom.domain.local
external-dns.alpha.kubernetes.io/coredns-group: "g2"
spec:
type: LoadBalancer
status:
loadBalancer:
ingress:
- ip: 127.0.0.3
---
apiVersion: v1
kind: Service
metadata:
name: d
annotations:
external-dns.alpha.kubernetes.io/hostname: d.subdom.domain.local
external-dns.alpha.kubernetes.io/coredns-group: "g2"
spec:
type: LoadBalancer
status:
loadBalancer:
ingress:
- ip: 127.0.0.4
And we want domain.local to return (127.0.0.1 and 127.0.0.2) and subdom.domain.local to return (127.0.0.3 and 127.0.0.4).
For this the two domains, need to be in different groups. What those groups are does not matter,
as long as a and b belong to the same group which is different from the group c and d belong to.
If a service is found without a group it is always included.