mirror of
https://github.com/kubernetes-sigs/external-dns.git
synced 2025-08-06 01:26:59 +02:00
149 lines
4.7 KiB
Markdown
149 lines
4.7 KiB
Markdown
# 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`. Refer to the [IPv6 Behavior](#ipv6-behavior) section for more details.
|
|
The TTL of the records can be set with the `external-dns.alpha.kubernetes.io/ttl` node annotation.
|
|
|
|
Nodes marked as **Unschedulable** as per [core/v1/NodeSpec](https://pkg.go.dev/k8s.io/api@v0.31.1/core/v1#NodeSpec) are excluded by default.
|
|
As such, no DNS records are created for Unhealthy, NotReady or SchedulingDisabled (cordon) nodes (and existing ones are removed).
|
|
In case you want to override the default, for example if you manage per-host DNS records via ExternalDNS, you can specify `--no-exclude-unschedulable` to always expose nodes no matter their status.
|
|
|
|
## IPv6 Behavior
|
|
|
|
By default, ExternalDNS exposes the IPv6 `ExternalIP` of the nodes.
|
|
If needed, one can still explicitly expose the internal ipv6 addresses by using the `--expose-internal-ipv6` flag.
|
|
|
|
### Example spec
|
|
|
|
```yaml
|
|
spec:
|
|
serviceAccountName: external-dns
|
|
containers:
|
|
- name: external-dns
|
|
image: registry.k8s.io/external-dns/external-dns:v0.18.0 # update this to the desired external-dns version
|
|
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 without RBAC enabled)
|
|
|
|
```yaml
|
|
---
|
|
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:v0.18.0
|
|
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)
|
|
|
|
```yaml
|
|
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","pods"]
|
|
verbs: ["get","watch","list"]
|
|
- apiGroups: ["discovery.k8s.io"]
|
|
resources: ["endpointslices"]
|
|
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:v0.18.0
|
|
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
|
|
```
|