Setup TLS connection on the API server. Rationale: API server communication contains sensitive parameters that should remain encrypted in transit. Configure the API server to serve only HTTPS traffic. Impact: TLS and client certificate authentication must be configured for your Kubernetes cluster deployment. By default, OpenShift uses X.509 certificates to provide secure connections between the API server and node/kubelet. OpenShift Container Platform monitors certificates for proper validity, for the cluster certificates it issues and manages. The OpenShift Container Platform manages certificate rotation and the alerting framework has rules to help identify when a certificate issue is about to occur.
Solution
OpenShift automatically manages TLS authentication for the API server communication with the node/kublet. This is not configurable. You may optionally set a custom default certificate to be used by the API server when serving content in order to enable clients to access the API server at a different host name or without the need to distribute the cluster-managed certificate authority (CA) certificates to the clients. Follow the directions in the OpenShift documentation User-provided certificates for the API server Default Value: By default, OpenShift uses X.509 certificates to provide secure connections between the API server and node/kubelet. OpenShift does not use values assigned to the tls-cert-file or tls-private-key-file flags.