Annotations¶
ExternalDNS sources support a number of annotations on the Kubernetes resources that they examine.
The following table documents which sources support which annotations:
| Source | controller | hostname | internal-hostname | target | ttl | (provider-specific) |
|---|---|---|---|---|---|---|
| Ambassador | Yes | Yes | Yes | |||
| Connector | ||||||
| Contour | Yes | Yes1 | Yes | Yes | Yes | |
| CloudFoundry | ||||||
| CRD | ||||||
| F5 | Yes | Yes | ||||
| Gateway | Yes | Yes1 | Yes4 | Yes | Yes | |
| Gloo | Yes | Yes5 | Yes5 | |||
| Ingress | Yes | Yes1 | Yes | Yes | Yes | |
| Istio | Yes | Yes1 | Yes | Yes | Yes | |
| Kong | Yes1 | Yes | Yes | Yes | ||
| Node | Yes | Yes | Yes | |||
| OpenShift | Yes | Yes1 | Yes | Yes | Yes | |
| Pod | Yes | Yes | Yes | |||
| Service | Yes | Yes1 | Yes12 | Yes3 | Yes | Yes |
| Skipper | Yes | Yes1 | Yes | Yes | Yes | |
| Traefik | Yes1 | Yes | Yes | Yes |
external-dns.alpha.kubernetes.io/access¶
Specifies which set of node IP addresses to use for a Service of type NodePort.
If the value is public, use the Nodes’ addresses of type ExternalIP, plus IPv6 addresses of type InternalIP.
If the value is private, use the Nodes’ addresses of type InternalIP.
If the annotation is not present and there is at least one address of type ExternalIP,
behave as if the value were public, otherwise behave as if the value were private.
external-dns.alpha.kubernetes.io/controller¶
If this annotation exists and has a value other than dns-controller then the source ignores the resource.
external-dns.alpha.kubernetes.io/endpoints-type¶
Specifies which set of addresses to use for a headless Service.
If the value is NodeExternalIP, use each relevant Pod’s Node’s address of type ExternalIP
plus each IPv6 address of type InternalIP.
Otherwise, if the value is HostIP or the --publish-host-ip flag is specified, use
each relevant Pod’s Status.HostIP.
Otherwise, use the IP of each of the Service’s Endpoints’s Addresses.
external-dns.alpha.kubernetes.io/hostname¶
Specifies the domain for the resource’s DNS records.
external-dns.alpha.kubernetes.io/ingress-hostname-source¶
Specifies where to get the domain for an Ingress resource.
If the value is defined-hosts-only, use only the domains from the Ingress spec.
If the value is annotation-only, use only the domains from the Ingress annotations.
If the annotation is not present, use the domains from both the spec and annotations.
external-dns.alpha.kubernetes.io/internal-hostname¶
Specifies the domain for the resource’s DNS records that are for use from internal networks.
For Services of type LoadBalancer, uses the Service’s ClusterIP.
For Pods, uses the Pod’s Status.PodIP.
external-dns.alpha.kubernetes.io/target¶
Specifies a comma-separated list of values to override the resource’s DNS record targets (RDATA).
Targets that parse as IPv4 addresses are published as A records and
targets that parse as IPv6 addresses are published as AAAA records. All other targets
are published as CNAME records.
external-dns.alpha.kubernetes.io/ttl¶
Specifies the TTL (time to live) for the resource’s DNS records.
The value may be specified as either a duration or an integer number of seconds.
It must be between 1 and 2,147,483,647 seconds.
Provider-specific annotations¶
Some providers define their own annotations. Cloud-specific annotations have keys prefixed as follows:
| Cloud | Annotation prefix |
|---|---|
| AWS | external-dns.alpha.kubernetes.io/aws- |
| CloudFlare | external-dns.alpha.kubernetes.io/cloudflare- |
| IBM Cloud | external-dns.alpha.kubernetes.io/ibmcloud- |
| Scaleway | external-dns.alpha.kubernetes.io/scw- |
Additional annotations that are currently implemented only by AWS are:
external-dns.alpha.kubernetes.io/alias¶
If the value of this annotation is true, specifies that CNAME records generated by the
resource should instead be alias records.
This annotation is only relevant if the --aws-prefer-cname flag is specified.
external-dns.alpha.kubernetes.io/set-identifier¶
Specifies the set identifier for DNS records generated by the resource.
A set identifier differentiates among multiple DNS record sets that have the same combination of domain and type.
Which record set or sets are returned to queries is then determined by the configured routing policy.