Configuring ExternalDNS to use Gateway API Route Sources¶
This describes how to configure ExternalDNS to use Gateway API Route sources.
It is meant to supplement the other provider-specific setup tutorials.
Supported API Versions¶
As the Gateway API is still in an experimental phase, ExternalDNS makes no backwards
compatibilty guarantees regarding its support. However, it currently supports a mixture of
v1alpha2, v1beta1, v1 APIs. Gateways and HTTPRoutes are supported using the v1 and v1beta1 API (which is converted to v1 when using the latest CRDs).
GRPCRoutes, TLSRoutes, TCPRoutes, and UDPRoutes are supported using the v1alpha2 API.
Hostnames¶
HTTPRoute and TLSRoute specs, along with their associated Gateway Listeners, contain hostnames that
will be used by ExternalDNS. However, no such hostnames may be specified in TCPRoute or UDPRoute
specs. For TCPRoutes and UDPRoutes, the external-dns.alpha.kubernetes.io/hostname annotation
is the recommended way to provide their hostnames to ExternalDNS. This annotation is also supported
for HTTPRoutes and TLSRoutes by ExternalDNS, but it’s strongly recommended that they use their
specs to provide all intended hostnames, since the Gateway that ultimately routes their
requests/connections won’t recognize additional hostnames from the annotation.
Manifest with RBAC¶
apiVersion: v1
kind: ServiceAccount
metadata:
name: external-dns
namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: external-dns
rules:
- apiGroups: [""]
resources: ["namespaces"]
verbs: ["get","watch","list"]
- apiGroups: ["gateway.networking.k8s.io"]
resources: ["gateways","httproutes","grpcroutes","tlsroutes","tcproutes","udproutes"]
verbs: ["get","watch","list"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: external-dns
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: external-dns
subjects:
- kind: ServiceAccount
name: external-dns
namespace: default
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
namespace: default
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:v0.14.1
args:
# Add desired Gateway API Route sources.
- --source=gateway-httproute
- --source=gateway-grpcroute
- --source=gateway-tlsroute
- --source=gateway-tcproute
- --source=gateway-udproute
# Optionally, limit Routes to those in the given namespace.
- --namespace=my-route-namespace
# Optionally, limit Routes to those matching the given label selector.
- --label-filter=my-route-label==my-route-value
# Optionally, limit Route endpoints to those Gateways in the given namespace.
- --gateway-namespace=my-gateway-namespace
# Optionally, limit Route endpoints to those Gateways matching the given label selector.
- --gateway-label-filter=my-gateway-label==my-gateway-value
# Add provider-specific flags...
- --domain-filter=external-dns-test.my-org.com
- --provider=google
- --registry=txt
- --txt-owner-id=my-identifier