1. Add the following "location" line to the undertow default host in standalone.xml: <host name="default-host" alias="localhost">                     <location name="/hosting/" handler="hosting-proxy"/>                     <location name="/" handler="welcome-content"/>                     <http-invoker http-authentication-factory="application-http-authentication"/>                 </host> 2. and these "reverse-proxy" lines to undertow handlers: <handlers>                 <file name="welcome-content" path="${jboss.home.dir}/welcome-content"/>                 <reverse-proxy name="hosting-proxy">                     <host name="localhost" outbound-socket-binding="apache2" scheme="https" path="/hosting/"/>                 </reverse-proxy>                 </handlers> 3. and this outbound-socket binding to "socket-binding-group": <socket-binding-group name="standard-sockets" default-interface="loopback" port-offset="${jboss.socket.binding.port-offset:0}">         <socket-binding name="ajp" interface="loopback" port="${jboss.ajp.port:8009}"/>         <socket-binding name="http" interface="loopback" port="${jboss.http.port:8080}"/>         <socket-binding name="https" interface="public" port="${jboss.https.port:443}"/>         <socket-binding name="management-http" interface="loopback" port="${jboss.management.http.port:9990}"/>         <socket-binding name="management-https" interface="public" port="${jboss.management.https.port:9993}"/>         <socket-binding name="management-native" interface="loopback" port="${jboss.management.native.port:9999}"/>         <socket-binding name="txn-recovery-environment" port="4712"/>         <socket-binding name="txn-status-manager" port="4713"/>         <outbound-socket-binding name="apache2">             <remote-destination host="localhost" port="80"/>         </outbound-socket-binding>     </socket-binding-group>   4. Restart Wildfly 5. Make sure page can be loaded directly from apache2 thereby bypassing the undertow reverse proxy: wget --no-check-certificate https://localhost:80/hosting/capabilities { }2022-02-14 11:38:46{ }   https://localhost:80/hosting/capabilities Resolving localhost (localhost)... ::1, 127.0.0.1 Connecting to localhost (localhost)|::1|:80... connected. WARNING: The certificate of ‘localhost’ is not trusted. WARNING: The certificate of ‘localhost’ doesn't have a known issuer. HTTP request sent, awaiting response... 200 OK Length: 274 [application/json] Saving to: ‘capabilities’ capabilities                               100% [=====================================================================================>]     274  --.-KB/s    in 0s       2022-02-14 11:38:46 (8.66 MB/s) - ‘capabilities’ saved [274/274] 6. Try the same URL but with port 443 (Wildfly / Undertow):  wget --no-check-certificate https://localhost:443/hosting/capabilities { }2022-02-14 11:39:20{ }   https://localhost/hosting/capabilities Resolving localhost (localhost)... ::1, 127.0.0.1 Connecting to localhost (localhost)|::1|:443... failed: Connection refused. Connecting to localhost (localhost)|127.0.0.1|:443... connected. WARNING: The certificate of ‘localhost’ is not trusted. WARNING: The certificate of ‘localhost’ doesn't have a known issuer. HTTP request sent, awaiting response... 503 Service Unavailable 2022-02-14 11:39:20 ERROR 503: Service Unavailable.