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. If --client-ca-file argument is set, any request presenting a client certificate signed by one of the authorities in the client-ca-file is authenticated with an identity corresponding to the CommonName of the client certificate. 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 alerting framework has rules to help identify when a certificate issue is about to occur. These rules consist of the following checks: API server client certificate expiration is less than five minutes.
Solution
None. Default Value: By default, OpenShift configures the client-ca-file and automatically manages the certificate. It does not use the value assigned to the client-ca-file flag. 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. Please follow the OpenShift documentation for providing certificates for OpenShift to use.