Chapter 7. Configuring certificates for hosted control planes

Procedure

1. Create a secret with your custom certificate by entering the following command:

   $ oc create secret tls sample-hosted-kas-custom-cert \
     --cert=path/to/cert.crt \
     --key=path/to/key.key \
     -n <hosted_cluster_namespace>

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2. Update your HostedCluster configuration with the custom certificate details, as shown in the following example:

   spec:
     configuration:
       apiServer:
         servingCerts:
           namedCertificates:
           - names: 

   1

   
             - api-custom-cert-sample-hosted.sample-hosted.example.com
             servingCertificate: 

   2

   
               name: sample-hosted-kas-custom-cert

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   1

   The list of DNS names that the certificate is valid for.

   2

   The name of the secret that contains the custom certificate.

3. Apply the changes to your HostedCluster configuration by entering the following command:

   $ oc apply -f <hosted_cluster_config>.yaml

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Procedure

1. In your provider platform, configure the DNS record so that the kubeAPIServerDNSName URL points to the IP address that the Kubernetes API server is being exposed to. The DNS record must be properly configured and resolvable from your cluster.

   Example command to configure the DNS record

   $ dig + short kubeAPIServerDNSName

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2. In your HostedCluster specification, modify the kubeAPIServerDNSName field, as shown in the following example:

   apiVersion: hypershift.openshift.io/v1beta1
   kind: HostedCluster
   metadata:
     name: <hosted_cluster_name>
     namespace: <hosted_cluster_namespace>
   spec:
     configuration:
       apiServer:
         servingCerts:
           namedCertificates:
           - names: 

   1

   
             - api-custom-cert-sample-hosted.sample-hosted.example.com
             servingCertificate: 

   2

   
               name: sample-hosted-kas-custom-cert
     kubeAPIServerDNSName: api-custom-cert-sample-hosted.sample-hosted.example.com 

   3

   
   # ...

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   1

   The list of DNS names that the certificate is valid for. The names listed in this field cannot be the same as the names specified in the spec.servicePublishingStrategy.*hostname field.

   2

   The name of the secret that contains the custom certificate.

   3

   This field accepts a URI that will be used as the API server endpoint.

3. Apply the configuration by entering the following command:

   $ oc -f <hosted_cluster_spec>.yaml

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   After the configuration is applied, the HyperShift Operator generates a new kubeconfig secret that points to your custom DNS domain.

4. Retrieve the kubeconfig secret by using the CLI or the console.

   1. To retrieve the secret by using the CLI, enter the following command:

      $ kubectl get secret <hosted_cluster_name>-custom-admin-kubeconfig \
        -n <cluster_namespace> \
        -o jsonpath='{.data.kubeconfig}' | base64 -d

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   2. To retrieve the secret by using the console, go to your hosted cluster and click Download Kubeconfig.

      Note

      You cannot consume the new kubeconfig secret by using the show login command option in the console.

Procedure

1. Verify that the DNS record is properly configured and resolved.

2. Check that the TLS certificates for the custom domain are valid, verifying that the SAN is correct for your domain, by entering the following command:

   $ oc get secret \
     -n clusters <serving_certificate_name> \
     -o jsonpath='{.data.tls\.crt}' | base64 \
     -d |openssl x509 -text -noout -

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3. Ensure that network connectivity to the custom domain is working.

4. In the HostedCluster resource, verify that the status shows the correct custom kubeconfig information, as shown in the following example:

   Example HostedCluster status

   status:
     customKubeconfig:
       name: sample-hosted-custom-admin-kubeconfig

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5. Check the kube-apiserver logs in the HostedControlPlane namespace by entering the following command:

   $ oc logs -n <hosted_control_plane_namespace> \
     -l app=kube-apiserver -f -c kube-apiserver

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