Configuring ExternalDNS to use Cluster Nodes as Source¶
This tutorial describes how to configure ExternalDNS to use the cluster nodes as source.
Using nodes (--source=node
) as source is possible to synchronize a DNS zone with the nodes of a cluster.
The node source adds an A
record per each node externalIP
(if not found, any IPv4 internalIP
is used instead).
It also adds an AAAA
record per each node IPv6 internalIP
.
The TTL of the records can be set with the external-dns.alpha.kubernetes.io/ttl
node annotation.
Manifest (for cluster without RBAC enabled)¶
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
spec:
strategy:
type: Recreate
selector:
matchLabels:
app: external-dns
template:
metadata:
labels:
app: external-dns
spec:
serviceAccountName: external-dns
containers:
- name: external-dns
image: registry.k8s.io/external-dns/external-dns:v0.14.2
args:
- --source=node # will use nodes as source
- --provider=aws
- --zone-name-filter=external-dns-test.my-org.com # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
- --domain-filter=external-dns-test.my-org.com
- --aws-zone-type=public
- --registry=txt
- --fqdn-template={{.Name}}.external-dns-test.my-org.com
- --txt-owner-id=my-identifier
- --policy=sync
- --log-level=debug
Manifest (for cluster with RBAC enabled)¶
apiVersion: v1
kind: ServiceAccount
metadata:
name: external-dns
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: external-dns
rules:
- apiGroups: ["route.openshift.io"]
resources: ["routes"]
verbs: ["get", "watch", "list"]
- apiGroups: [""]
resources: ["services","endpoints","pods"]
verbs: ["get","watch","list"]
- apiGroups: ["extensions","networking.k8s.io"]
resources: ["ingresses"]
verbs: ["get","watch","list"]
- apiGroups: [""]
resources: ["nodes"]
verbs: ["get", "watch", "list"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: external-dns-viewer
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: external-dns
subjects:
- kind: ServiceAccount
name: external-dns
namespace: external-dns
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
spec:
strategy:
type: Recreate
selector:
matchLabels:
app: external-dns
template:
metadata:
labels:
app: external-dns
spec:
serviceAccountName: external-dns
containers:
- name: external-dns
image: registry.k8s.io/external-dns/external-dns:v0.14.2
args:
- --source=node # will use nodes as source
- --provider=aws
- --zone-name-filter=external-dns-test.my-org.com # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
- --domain-filter=external-dns-test.my-org.com
- --aws-zone-type=public
- --registry=txt
- --fqdn-template={{.Name}}.external-dns-test.my-org.com
- --txt-owner-id=my-identifier
- --policy=sync
- --log-level=debug