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* chore(release): updates kustomize & docs with v0.17.0 Signed-off-by: Michel Loiseleur <michel.loiseleur@traefik.io> * add optional workflow dispatch for doc * review --------- Signed-off-by: Michel Loiseleur <michel.loiseleur@traefik.io>
148 lines
4.9 KiB
Markdown
148 lines
4.9 KiB
Markdown
# Cluster Nodes as Source
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This tutorial describes how to configure ExternalDNS to use the cluster nodes as source.
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Using nodes (`--source=node`) as source is possible to synchronize a DNS zone with the nodes of a cluster.
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The node source adds an `A` record per each node `externalIP` (if not found, any IPv4 `internalIP` is used instead).
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It also adds an `AAAA` record per each node IPv6 `internalIP`. Refer to the [IPv6 Behavior](#ipv6-behavior) section for more details.
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The TTL of the records can be set with the `external-dns.alpha.kubernetes.io/ttl` node annotation.
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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.
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As such, no DNS records are created for Unhealthy, NotReady or SchedulingDisabled (cordon) nodes (and existing ones are removed).
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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.
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## IPv6 Behavior
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By default, ExternalDNS exposes the IPv6 `InternalIP` of the nodes. To prevent this, you can use the `--no-expose-internal-ipv6` flag.
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**The default behavior will change in the next minor release.** ExternalDNS will no longer expose the IPv6 `InternalIP` addresses by default.
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You can still explicitly expose the internal ipv6 addresses by using the `--expose-internal-ipv6` flag, if needed.
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### Example spec (without exposing IPv6 `InternalIP` addresses)
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```yaml
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spec:
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serviceAccountName: external-dns
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containers:
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- name: external-dns
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image: registry.k8s.io/external-dns/external-dns:v0.17.0 # update this to the desired external-dns version
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args:
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- --source=node # will use nodes as source
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- --provider=aws
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- --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
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- --domain-filter=external-dns-test.my-org.com
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- --aws-zone-type=public
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- --registry=txt
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- --fqdn-template={{.Name}}.external-dns-test.my-org.com
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- --txt-owner-id=my-identifier
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- --policy=sync
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- --log-level=debug
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- --no-expose-internal-ipv6
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```
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## Manifest (for cluster without RBAC enabled)
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```yaml
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---
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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name: external-dns
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spec:
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strategy:
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type: Recreate
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selector:
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matchLabels:
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app: external-dns
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template:
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metadata:
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labels:
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app: external-dns
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spec:
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serviceAccountName: external-dns
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containers:
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- name: external-dns
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image: registry.k8s.io/external-dns/external-dns:v0.17.0
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args:
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- --source=node # will use nodes as source
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- --provider=aws
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- --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
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- --domain-filter=external-dns-test.my-org.com
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- --aws-zone-type=public
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- --registry=txt
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- --fqdn-template={{.Name}}.external-dns-test.my-org.com
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- --txt-owner-id=my-identifier
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- --policy=sync
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- --log-level=debug
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```
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## Manifest (for cluster with RBAC enabled)
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```yaml
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apiVersion: v1
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kind: ServiceAccount
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metadata:
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name: external-dns
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---
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apiVersion: rbac.authorization.k8s.io/v1
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kind: ClusterRole
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metadata:
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name: external-dns
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rules:
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- apiGroups: ["route.openshift.io"]
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resources: ["routes"]
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verbs: ["get", "watch", "list"]
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- apiGroups: [""]
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resources: ["services","endpoints","pods"]
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verbs: ["get","watch","list"]
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- apiGroups: ["extensions","networking.k8s.io"]
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resources: ["ingresses"]
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verbs: ["get","watch","list"]
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- apiGroups: [""]
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resources: ["nodes"]
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verbs: ["get", "watch", "list"]
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---
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apiVersion: rbac.authorization.k8s.io/v1
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kind: ClusterRoleBinding
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metadata:
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name: external-dns-viewer
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roleRef:
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apiGroup: rbac.authorization.k8s.io
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kind: ClusterRole
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name: external-dns
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subjects:
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- kind: ServiceAccount
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name: external-dns
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namespace: external-dns
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---
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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name: external-dns
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spec:
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strategy:
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type: Recreate
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selector:
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matchLabels:
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app: external-dns
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template:
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metadata:
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labels:
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app: external-dns
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spec:
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serviceAccountName: external-dns
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containers:
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- name: external-dns
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image: registry.k8s.io/external-dns/external-dns:v0.17.0
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args:
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- --source=node # will use nodes as source
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- --provider=aws
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- --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
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- --domain-filter=external-dns-test.my-org.com
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- --aws-zone-type=public
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- --registry=txt
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- --fqdn-template={{.Name}}.external-dns-test.my-org.com
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- --txt-owner-id=my-identifier
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- --policy=sync
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- --log-level=debug
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```
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