Creating DNS records on an public hosted zone for AWS by using Red Hat External DNS Operator

You can create DNS records on a public hosted zone for AWS by using the Red Hat External DNS Operator.

Procedure

  1. Check the user. The user must have access to the kube-system namespace. If you don’t have the credentials, as you can fetch the credentials from the kube-system namespace to use the cloud provider client:

    1. $ oc whoami

    Example output

    1. system:admin

  2. Fetch the values from aws-creds secret present in kube-system namespace.

    1. $ export AWS_ACCESS_KEY_ID=$(oc get secrets aws-creds -n kube-system  --template={{.data.aws_access_key_id}} | base64 -d)
    2. $ export AWS_SECRET_ACCESS_KEY=$(oc get secrets aws-creds -n kube-system  --template={{.data.aws_secret_access_key}} | base64 -d)

  3. Get the routes to check the domain:

    1. $ oc get routes --all-namespaces | grep console

    Example output

    1. openshift-console          console             console-openshift-console.apps.testextdnsoperator.apacshift.support                       console             https   reencrypt/Redirect     None
    2. openshift-console          downloads           downloads-openshift-console.apps.testextdnsoperator.apacshift.support                     downloads           http    edge/Redirect          None

  4. Get the list of dns zones to find the one which corresponds to the previously found route’s domain:

    1. $ aws route53 list-hosted-zones | grep testextdnsoperator.apacshift.support

    Example output

    1. HOSTEDZONES    terraform    /hostedzone/Z02355203TNN1XXXX1J6O    testextdnsoperator.apacshift.support.    5

  5. Create ExternalDNS CR for route source:

    1. apiVersion: externaldns.olm.openshift.io/v1alpha1
    2. kind: ExternalDNS
    3. metadata:
    4.   name: sample-aws (1)
    5. spec:
    6.   domains:
    7.   - filterType: Include   (2)
    8.     matchType: Exact   (3)
    9.     name: testextdnsoperator.apacshift.support (4)
    10.     provider:
    11.       type: AWS (5)
    12.     source:  (6)
    13.       type: OpenShiftRoute (7)
    14.       openshiftRouteOptions:
    15.         routerName: default (8)
    1Defines the name of external DNS CR.
    2By default all hosted zones are selected as potential targets. You can include a hosted zone that you need.
    3The matching of the target zone’s domain has to be exact (as opposed to regular expression match).
    4Specify the exact domain of the zone you want to update. The hostname of the routes must be subdomains of the specified domain.
    5Defines the AWS Route53 DNS provider.
    6Defines options for the source of DNS records.
    7Defines OpenShift route resource as the source for the DNS records which gets created in the previously specified DNS provider.
    8If the source is OpenShiftRoute, then you can pass the OpenShift Ingress Controller name. External DNS Operator selects the canonical hostname of that router as the target while creating CNAME record.

  6. Check the records created for OCP routes using the following command:

    1. $ aws route53 list-resource-record-sets --hosted-zone-id Z02355203TNN1XXXX1J6O --query "ResourceRecordSets[?Type == 'CNAME']" | grep console