On Wildfly 26.1.1, Debian Buster and Temurin 17.0.4, I cannot use the smallrye-graphql-client  because its netty dns resolution ignores the system defaults and uses Google's public DNS servers as a fallback. As netty-resolver-dns is bundled as a module in Wildfly, I thought I should address this issue here.

Netty tries to use JNDI to lookup the DNS servers, but fails (silently with an empty catch block!) in io.netty.resolver.dns.DirContextUtils#addNameServers with 

java.lang.IllegalAccessException: class org.jboss.as.naming.InitialContext cannot access class com.sun.jndi.dns.DnsContextFactory (in module jdk.naming.dns) because module jdk.naming.dns does not export com.sun.jndi.dns to unnamed module @32a32c84

 and then defaults to Google. 

We fixed this by adding 

--add-exports=jdk.naming.dns/com.sun.jndi.dns=ALL-UNNAMED

to our JAVA_OPTS. Should this be set per default in WildFly, given it bundles this netty module?

Extra concerning: in our environments we experienced DNS timeouts as the Internet is blocked, but if it wasn't blocked, we'd have leaked our DNS requests unencrypted over the public internet to Google.