Expose Kubernetes Service with External DNS and Route53

There are 3 ways you can expose your service on kubernetes for external accessing

1. LoadBalancer

2. NodePort the service address would be your worker node with node port assigned <NodeIP>:<NodePort>

3. Ingress (Note. there is a pre-requisite for AWS ALB Ingress Controller https://docs.aws.amazon.com/eks/latest/userguide/alb-ingress.html)

We can use External DNS to sync the exposed service and ingress with AWS Route53

To know more about Kubernetes external DNS https://github.com/kubernetes-sigs/external-dns

External DNS

If EKS version > 1.13, you can use an IAM service account directly as below

1. Create Hosted Zone on AWS Route53

aws route53 create-hosted-zone --name "external-dns-test.my-org.com." --caller-reference "external-dns-test-$(date +%s)"

2. Create IAM policy

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "route53:ChangeResourceRecordSets"
      ],
      "Resource": [
        "arn:aws:route53:::hostedzone/*"
      ]
    },
    {
      "Effect": "Allow",
      "Action": [
        "route53:ListHostedZones",
        "route53:ListResourceRecordSets"
      ],
      "Resource": [
        "*"
      ]
    }
  ]
}

3. Create IAM role for service account

eksctl create iamserviceaccount \
 — name external-dns \
 — namespace kube-system \
 — cluster YOUR_CLUSTER_NAME \
 — attach-policy-arn YOUR_IAM_POLICY_ARN \
 — approve

4. Check service account IAM role

kubectl describe sa external-dns -n kube-system

5. Deploy External DNS

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: external-dns
rules:
- apiGroups: [""]
  resources: ["services","endpoints","pods"]
  verbs: ["get","watch","list"]
- apiGroups: ["extensions"]
  resources: ["ingresses"]
  verbs: ["get","watch","list"]
- apiGroups: [""]
  resources: ["nodes"]
  verbs: ["list","watch"]
---
apiVersion: rbac.authorization.k8s.io/v1beta1
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: 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.opensource.zalan.do/teapot/external-dns:latest
        args:
        - --source=service
        - --source=ingress
        - --domain-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
        - --provider=aws
        - --policy=upsert-only # would prevent ExternalDNS from deleting any records, omit to enable full synchronization
        - --aws-zone-type=public # only look at public hosted zones (valid values are public, private or no value for both)
        - --registry=txt
        - --txt-owner-id=my-hostedzone-identifier
      securityContext:
        fsGroup: 65534 # For ExternalDNS to be able to read Kubernetes and AWS token filesLoadBalancer 

LoadBalancer

To use LoadBalancer, change your service yaml file type:LoadBalancer and add annotation for your external DNS hostname external-dns.alpha.kubernetes.io/hostname

apiVersion: v1
kind: Service
metadata:
  name: test
  annotations:
    external-dns.alpha.kubernetes.io/hostname: yourservice.external-dns-test.my-org.com 
spec:
  type: LoadBalancer
  ports:
  - port: 80
    name: http
    targetPort: 80
  selector:
    app: test

NodePort

To use NodePort, change your service yaml file type: Nodeportand add annotation for your external DNS hostname

apiVersion: v1
kind: Service
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: yourservice.external-dns-test.my-org.com
  name: test
spec:
  externalIPs:
  - 1.2.3.4
  - 4.5.6.7
  externalTrafficPolicy: Cluster
  ports:
  - nodePort: 30001 #will give you a random 3XXXX port
    port: 5000
    protocol: TCP
    targetPort: 5000
  selector:
    app: test
  type: NodePort

Ingress

To use Ingress, add the following yaml file with annotation for your external DNS hostname. (Note. there is a pre-requisite for AWS ALB Ingress Controller https://docs.aws.amazon.com/eks/latest/userguide/alb-ingress.html)

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    alb.ingress.kubernetes.io/scheme: internet-facing
    external-dns.alpha.kubernetes.io/hostname: yourservice.external-dns-test.my-org.com
    kubernetes.io/ingress.class: alb
  name: test
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: test
          servicePort: 80
        path: /

My Working Version