Renew Kubernetes certificates before or after expiry to maintain secure cluster operations in Crosswork Network Controller.
Kubernetes certificate renewal
Certificates are valid for one year before they expire. After you renew the certificates, ensure that the pods are healthy before resuming other operations.
If you renew certificates before they expire, it is recommended to perform this activity during a maintenance window to keep the cluster in an operational state.
To renew a certificate, perform these steps:
Before you begin
-
Create a plain text file on your local machine (for example,
password.txt) that contains the SSH login password for the server. -
Keep the management IP addresses readily available for the hybrid and worker nodes in your cluster.
Procedure
Automatic renewal of internal certificates
Crosswork CA generates TLS certificate chains, including root, intermediate CA, and leaf certificates, for day 0 deployments (Geo HA and non-Geo HA). The leaf certificates are valid for 2 years, while root and intermediate CA certificates are valid for 5 years. Customers with Crosswork deployments lasting beyond two years will face certificate expiry. This expiry disrupts TLS communication and impacts cluster operations. Auto-renewal applies to all Crosswork certificates generated internally, including NATS, Kafka, and any application-specific internal certificates.
The renewal alert is generated only when the expiry period is less than 90 days. When an internal certificate is expiring and renewed, all internal certificates of that type will be renewed. For example, when a leaf certificate is renewed, the process will also renew all other leaf certificates.
For geo HA deployment:
For a Geo HA deployment, the certificate renewal is triggered in the active AZ cluster. The TLS manager determines if the cluster has geo redundancy enabled or disabled and decides whether the certificate renewal must be performed on one cluster or both geo HA clusters. After the renewal job is completed on the active cluster, the job automatically runs in the standby cluster after a delay. The standby cluster then displays job progress and alarm events.
In a Geo HA setup with auto-arbitration, the certificate is first renewed on the active cluster, then simultaneously renewed on the standby cluster and the arbiter VM.
The certificate renewal process can cause a downtime of approximately thirty minutes to one hour. It is recommended to perform this activity during a maintenance window to avoid disrupting cluster operations.
To renew an internal certificate, perform the following: