Feature: Basic support for automatically obtaining and updating certificates using the ACME protocol, configurable with the acme_client and acme directives, as well as variables of the form $acme_cert_* and $acme_cert_key_*.
Feature: Configuration of automatic redirection, which adds trailing slashes to request URIs, with the auto_redirect directive.
Feature: Output statistics metrics with dates in Epoch format instead of ISO 8601 for use in Prometheus and optionally in the JSON API with the ?date=epoch request argument.
Feature: New recovering state for upstream peers in the statistics API, indicating that a peer is slowly starting up after a failure, as suggested by the slow_start option.
Feature: Now the -V switch also shows the relevant version of nginx, which is useful for compatibility with third-party utilities, certbot in particular. Thanks to AdvTechnoKing.
Bugfix: If the SSL session reuse mechanism proxy_ssl_session_reuse was used and the list of proxied servers was dynamically updated, a leak could occur in the shared memory zone configured for the corresponding upstream block.