This tutorial describes how to setup ExternalDNS for usage within a kubernetes cluster that makes use of RDNS and nginx ingress controller.
You need to:
- install RDNS with etcd enabled
- install external-dns with rdns as a provider
git clone https://github.com/rancher/rdns-server.git
cd rdns-server
docker-compose -f deploy/etcdv3/etcd-compose.yaml up -d
ETCD was successfully deployed on
http://172.31.35.77:2379
export ETCD_ENDPOINTS="http://172.31.35.77:2379"
export DOMAIN="lb.rancher.cloud"
./scripts/start etcdv3
RDNS was successfully deployed on
172.31.35.77
ETCD_URLS is configured to etcd client service address. RDNS_ROOT_DOMAIN is configured to the same with RDNS DOMAIN environment. e.g. lb.rancher.cloud.
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
namespace: kube-system
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:v0.13.2
args:
- --source=ingress
- --provider=rdns
- --log-level=debug # debug only
env:
- name: ETCD_URLS
value: http://172.31.35.77:2379
- name: RDNS_ROOT_DOMAIN
value: lb.rancher.cloud
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: external-dns
rules:
- apiGroups: [""]
resources: ["services","endpoints","pods"]
verbs: ["get","watch","list"]
- apiGroups: ["extensions","networking.k8s.io"]
resources: ["ingresses"]
verbs: ["get","watch","list"]
- apiGroups: [""]
resources: ["nodes"]
verbs: ["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: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: external-dns
namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
namespace: kube-system
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:v0.13.2
args:
- --source=ingress
- --provider=rdns
- --log-level=debug # debug only
env:
- name: ETCD_URLS
value: http://172.31.35.77:2379
- name: RDNS_ROOT_DOMAIN
value: lb.rancher.cloud
$ cat ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:
- host: nginx.lb.rancher.cloud
http:
paths:
- backend:
serviceName: nginx
servicePort: 80
$ kubectl apply -f ingress.yaml
ingress.extensions "nginx" created
Wait a moment until DNS has the ingress IP. The RDNS IP in this example is "172.31.35.77".
$ kubectl get ingress
NAME HOSTS ADDRESS PORTS AGE
nginx nginx.lb.rancher.cloud 172.31.42.211 80 2m
$ kubectl run -it --rm --restart=Never --image=infoblox/dnstools:latest dnstools
If you don't see a command prompt, try pressing enter.
dnstools# dig @172.31.35.77 nginx.lb.rancher.cloud +short
172.31.42.211
dnstools#