TLS configuration for Redpanda and rpk

Setting up TLS on Redpanda and rpk involves acquiring a certificate and a key, with an optional truststore file for client authentication. Redpanda supports two levels of TLS: basic encryption of incoming requests and an enhanced version requiring client certificates for authentication. This configuration applies to the Apache Kafka®-compatible API, the Redpanda Admin API, and the internal RPC API. The process includes specifying listener addresses, configuring TLS settings for each API, and potentially using different certificates for added security. The rpk tool can be used to configure TLS settings, and changes to its configuration do not necessitate restarting Redpanda. Since Redpanda is API-compatible with Kafka, existing Kafka clients may not require significant changes unless file locations or formats are altered. TLS ensures encrypted communication and can enforce client authentication to restrict access to known clients, enhancing overall security.