Router: preResolveFQDN2IP

Java discovery-time hostname-to-IP conversion.

Type: Boolean. Default: false.

Meaning

In Java, optionally converts a discovered backend URI’s fully qualified domain name to an IP before storing its host in the router pool.

preResolveFQDN2IP: false

Retains https://api.example.com:8443 as a hostname-based target. Normal client/resolver behavior determines resolution; this does not mean DNS is necessarily queried for every request.

preResolveFQDN2IP: true

If discovery returns that URI and the hostname resolves to 192.0.2.10, the Java router stores a URI using 192.0.2.10. The conversion occurs when discovery hosts are added, which can happen on the first request, rather than being guaranteed at process startup. The inspected service_url branch does not use this discovery conversion.

The template recommends this only for selected downstream load-balancer cases. It can affect DNS rotation, Host headers, TLS SNI, and hostname verification, so verify those behaviors before using it for an HTTPS virtual host.

Rust support: the legacy spelling preResolveFQDN2IP is accepted, but the current gateway has no corresponding conversion wired to this property. Ordinary Pingora address resolution still occurs independently.

See Router configuration for Portal/values.yml syntax, runtime compatibility, and source references.