Certificate Management

Overview

Every K8SaaS cluster has a dedicated certificate authority (CA) generated at provisioning time. The CA signs all cluster component certificates (API server, etcd, kubelet) and kubeconfig client certificates. Administrators rotate the CA when certificates approach expiry, when credentials are suspected compromised, or after a security incident.

Rotating a cluster CA invalidates all existing kubeconfigs for that cluster. All project users with access to the cluster must re-download their credentials after rotation. Notify all users before performing a CA rotation.

View Cluster CA

Dashboard
CLI

Navigate to Container (admin view) > Clusters, click a cluster, and select Actions → Show CA to view the cluster’s current CA certificate (public key only).

Show cluster CA certificate

openstack coe ca show prod-cluster-01

The output displays the PEM-encoded CA certificate. Check the expiry date:

Check CA certificate expiry

openstack coe ca show prod-cluster-01 \
  | grep -A 20 "BEGIN CERTIFICATE" \
  | openssl x509 -noout -dates

Rotate the Cluster CA

CA rotation is irreversible. Existing kubeconfigs stop working immediately after rotation. Plan rotation during a maintenance window and prepare user communication in advance.

Dashboard
CLI

Notify users

Send advance notice to all users with cluster access that their kubeconfigs will be invalidated at the scheduled rotation time.

Initiate rotation

Navigate to Container (admin view) > Clusters, click the cluster, and select Actions → Rotate CA. Confirm the rotation.The cluster enters UPDATE_IN_PROGRESS during CA regeneration.

Wait for completion

Wait for the cluster to return to UPDATE_COMPLETE status.

Direct users to refresh

Notify all users to re-download their kubeconfig:

Refresh kubeconfig (user command)

openstack coe cluster config prod-cluster-01 \
  --dir ~/.kube \
  --force

All users can connect to the cluster with the new kubeconfig.

Rotate cluster CA

openstack coe ca rotate prod-cluster-01

Monitor rotation progress

openstack coe cluster show prod-cluster-01 \
  -f value -c status

Wait for status to return to UPDATE_COMPLETE.

Verify new CA certificate

openstack coe ca show prod-cluster-01

After rotation, all users must refresh their kubeconfig:

Refresh kubeconfig

openstack coe cluster config prod-cluster-01 \
  --dir ~/.kube \
  --force

New CA is in place and kubectl connects with the refreshed kubeconfig.

Certificate Expiry Planning

Plan CA rotations proactively to avoid service disruption from expired certificates.

Certificate	Default Validity	Action Required
Cluster CA	10 years	Rotate 90 days before expiry
API server TLS	1 year (auto-renewed)	Monitor via `openssl x509 -noout -dates`
Node kubelet certificates	1 year (auto-renewed)	Ensure `auto_healing_enabled=true` in template

Audit all cluster CA expiry dates

for cluster in $(openstack coe cluster list -f value -c name); do
  echo -n "$cluster: "
  openstack coe ca show $cluster \
    | grep -A 20 "BEGIN CERTIFICATE" \
    | openssl x509 -noout -enddate 2>/dev/null
done

Polystack Key Management Integration

For the highest security posture, store cluster CA private keys in Polystack Key Management rather than in the K8SaaS database.

Polystack Key Management must be deployed and the magnum service account must have the creator role on the Key Management service before enabling this integration.

Web Console
CLI

Open the deployment console Configuration

Navigate to the deployment console → Configuration and select the Advance Features tab.

Enable KMS

Set Enable KMS to Yes. This deploys the Polystack Key Management service and configures service account integration.

Set certificate manager type

Open the deployment console → Advanced Configuration, select magnum in the Service Tree, then open or create kubernetes.conf. Add the following in the Code Editor:

kubernetes.conf

[certificate]
cert_manager_type = barbican

Click Save Current File.

Deploy the changes

Navigate to the deployment console → Operations and run a Reconfigure for the Kubernetes and Key Management services.

K8SaaS is configured to store CA private keys in Polystack Key Management.

/etc/ironcore/kubernetes/kubernetes.conf

[certificate]
cert_manager_type = barbican

Restart API and Conductor after config change

docker restart magnum_api magnum_conductor

Next Steps

Security

Configure RBAC and node security groups alongside certificate management.

Monitoring

Monitor certificate expiry and cluster health across all projects.

Cluster Upgrades (User)

Advise users on refreshing kubeconfigs after upgrades and CA rotations.

Key Manager

Configure Polystack Key Management for secure CA private key storage.

Core Services

Other Services

Overview

View Cluster CA

Rotate the Cluster CA

Notify users

Initiate rotation

Wait for completion

Direct users to refresh

Certificate Expiry Planning

Polystack Key Management Integration

Open the deployment console Configuration

Enable KMS

Set certificate manager type

Deploy the changes

Next Steps

Security

Monitoring

Cluster Upgrades (User)

Key Manager

​Overview

​View Cluster CA

​Rotate the Cluster CA

Notify users

Initiate rotation

Wait for completion

Direct users to refresh

​Certificate Expiry Planning

​Polystack Key Management Integration

Open the deployment console Configuration

Enable KMS

Set certificate manager type

Deploy the changes

​Next Steps

Security

Monitoring

Cluster Upgrades (User)

Key Manager

Overview

View Cluster CA

Rotate the Cluster CA

Certificate Expiry Planning

Polystack Key Management Integration

Next Steps