# IBMCloud This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using IBMCloud DNS. This tutorial uses [IBMCloud CLI](https://cloud.ibm.com/docs/cli?topic=cli-getting-started) for all IBM Cloud commands and assumes that the Kubernetes cluster was created via IBM Cloud Kubernetes Service and `kubectl` commands are being run on an orchestration node. ## Creating a IBMCloud DNS zone The IBMCloud provider for ExternalDNS will find suitable zones for domains it manages; it will not automatically create zones. For public zone, This tutorial assume that the [IBMCloud Internet Services](https://cloud.ibm.com/catalog/services/internet-services) was provisioned and the [cis cli plugin](https://cloud.ibm.com/docs/cis?topic=cis-cli-plugin-cis-cli) was installed with IBMCloud CLI For private zone, This tutorial assume that the [IBMCloud DNS Services](https://cloud.ibm.com/catalog/services/dns-services) was provisioned and the [dns cli plugin](https://cloud.ibm.com/docs/dns-svcs?topic=dns-svcs-cli-plugin-dns-services-cli-commands) was installed with IBMCloud CLI ### Public Zone For this tutorial, we create public zone named `example.com` on IBMCloud Internet Services instance `external-dns-public` ``` $ ibmcloud cis domain-add example.com -i external-dns-public ``` Follow [step](https://cloud.ibm.com/docs/cis?topic=cis-getting-started#configure-your-name-servers-with-the-registrar-or-existing-dns-provider) to active your zone ### Private Zone For this tutorial, we create private zone named `example.com` on IBMCloud DNS Services instance `external-dns-private` ``` $ ibmcloud dns zone-create example.com -i external-dns-private ``` ## Creating configuration file The preferred way to inject the configuration file is by using a Kubernetes secret. The secret should contain an object named azure.json with content similar to this: ``` { "apiKey": "1234567890abcdefghijklmnopqrstuvwxyz", "instanceCrn": "crn:v1:bluemix:public:internet-svcs:global:a/bcf1865e99742d38d2d5fc3fb80a5496:b950da8a-5be6-4691-810e-36388c77b0a3::" } ``` You can create or find the `apiKey` in your ibmcloud IAM --> [API Keys page](https://cloud.ibm.com/iam/apikeys) You can find the `instanceCrn` in your service instance details Now you can create a file named 'ibmcloud.json' with values gathered above and with the structure of the example above. Use this file to create a Kubernetes secret: ``` $ kubectl create secret generic ibmcloud-config-file --from-file=/local/path/to/ibmcloud.json ``` ## Deploy ExternalDNS Connect your `kubectl` client to the cluster you want to test ExternalDNS with. Then apply one of the following manifests file to deploy ExternalDNS. ### Manifest (for clusters without RBAC enabled) ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: external-dns spec: strategy: type: Recreate selector: matchLabels: app: external-dns template: metadata: labels: app: external-dns spec: containers: - name: external-dns image: registry.k8s.io/external-dns/external-dns:v0.15.0 args: - --source=service # ingress is also possible - --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above. - --provider=ibmcloud - --ibmcloud-proxied # (optional) enable the proxy feature of IBMCloud volumeMounts: - name: ibmcloud-config-file mountPath: /etc/kubernetes readOnly: true volumes: - name: ibmcloud-config-file secret: secretName: ibmcloud-config-file items: - key: externaldns-config.json path: ibmcloud.json ``` ### Manifest (for clusters with RBAC enabled) ```yaml apiVersion: v1 kind: ServiceAccount metadata: name: external-dns --- 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", "watch"] --- 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: default --- apiVersion: apps/v1 kind: Deployment metadata: name: external-dns 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:v0.15.0 args: - --source=service # ingress is also possible - --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above. - --provider=ibmcloud - --ibmcloud-proxied # (optional) enable the proxy feature of IBMCloud public zone volumeMounts: - name: ibmcloud-config-file mountPath: /etc/kubernetes readOnly: true volumes: - name: ibmcloud-config-file secret: secretName: ibmcloud-config-file items: - key: externaldns-config.json path: ibmcloud.json ``` ## Deploying an Nginx Service Create a service file called `nginx.yaml` with the following contents: ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: nginx spec: selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - image: nginx name: nginx ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: nginx annotations: external-dns.alpha.kubernetes.io/hostname: www.example.com external-dns.alpha.kubernetes.io/ttl: "120" #optional spec: selector: app: nginx type: LoadBalancer ports: - protocol: TCP port: 80 targetPort: 80 ``` Note the annotation on the service; use the hostname as the IBMCloud DNS zone created above. The annotation may also be a subdomain of the DNS zone (e.g. 'www.example.com'). By setting the TTL annotation on the service, you have to pass a valid TTL, which must be 120 or above. This annotation is optional, if you won't set it, it will be 1 (automatic) which is 300. ExternalDNS uses this annotation to determine what services should be registered with DNS. Removing the annotation will cause ExternalDNS to remove the corresponding DNS records. Create the deployment and service: ``` $ kubectl create -f nginx.yaml ``` Depending where you run your service it can take a little while for your cloud provider to create an external IP for the service. Once the service has an external IP assigned, ExternalDNS will notice the new service IP address and synchronize the IBMCloud DNS records. ## Verifying IBMCloud DNS records Run the following command to view the A records: ### Public Zone ``` # Get the domain ID with below command on IBMCloud Internet Services instance `external-dns-public` $ ibmcloud cis domains -i external-dns-public # Get the records with domain ID $ ibmcloud cis dns-records DOMAIN_ID -i external-dns-public ``` ### Private Zone ``` # Get the domain ID with below command on IBMCloud DNS Services instance `external-dns-private` $ ibmcloud dns zones -i external-dns-private # Get the records with domain ID $ ibmcloud dns resource-records ZONE_ID -i external-dns-public ``` This should show the external IP address of the service as the A record for your domain. ## Cleanup Now that we have verified that ExternalDNS will automatically manage IBMCloud DNS records, we can delete the tutorial's example: ``` $ kubectl delete -f nginx.yaml $ kubectl delete -f externaldns.yaml ``` ## Setting proxied records on public zone Using the `external-dns.alpha.kubernetes.io/ibmcloud-proxied: "true"` annotation on your ingress or service, you can specify if the proxy feature of IBMCloud public DNS should be enabled for that record. This setting will override the global `--ibmcloud-proxied` setting. ## Active priviate zone with VPC allocated By default, IBMCloud DNS Services don't active your private zone with new zone added, with externale DNS, you can use `external-dns.alpha.kubernetes.io/ibmcloud-vpc: "crn:v1:bluemix:public:is:us-south:a/bcf1865e99742d38d2d5fc3fb80a5496::vpc:r006-74353823-a60d-42e4-97c5-5e2551278435"` annotation on your ingress or service, it will active your private zone with in specific VPC for that record created in. this setting won't work if the private zone was active already. Note: the annotaion value is the VPC CRN, every IBM Cloud service have a valid CRN.