Review user-provided TLS certificates for the API server in OKD to understand their purpose, location, management, and expiration for external client access.
The API server is accessible by clients external to the cluster at api.<cluster_name>.<base_domain>. You might want clients to access the API server at a different hostname or without the need to distribute the cluster-managed certificate authority (CA) certificates to the clients. The administrator must set a custom default certificate to be used by the API server when serving content.
The user-provided certificates must be provided in a kubernetes.io/tls type Secret in the openshift-config namespace. Update the API server cluster configuration, the apiserver/cluster resource, to enable the use of the user-provided certificate.