Netty DNS resolver fails to resolve computer's name on Windows

When running on a VM with Windows 10, Netty DNS resolver cannot resolve computer’s name.

Expected behavior

When on Windows, Netty DNS resolver is able to resolve the computer’s name

Actual behavior

The current implementation throws an exception when one tries to resolve the computer’s name

Caused by: java.net.UnknownHostException: failed to resolve 'DESKTOP-BHE9K15' after 2 queries 
	at io.netty.resolver.dns.DnsResolveContext.finishResolve(DnsResolveContext.java:1013)
	at io.netty.resolver.dns.DnsResolveContext.tryToFinishResolve(DnsResolveContext.java:966)
	at io.netty.resolver.dns.DnsResolveContext.query(DnsResolveContext.java:414)
	at io.netty.resolver.dns.DnsResolveContext.tryToFinishResolve(DnsResolveContext.java:938)
	at io.netty.resolver.dns.DnsResolveContext.access$700(DnsResolveContext.java:63)
	at io.netty.resolver.dns.DnsResolveContext$2.operationComplete(DnsResolveContext.java:467)

Minimal yet complete reproducer code (or URL to code)

public class Application {

    public static void main(String[] args) throws Exception {
        // JDK
        InetAddress[] addresses = InetAddress.getAllByName("DESKTOP-BHE9K15");
        System.out.println(Arrays.asList(addresses));

        // JDK
        InetAddress localhost = InetAddress.getLocalHost();
        System.out.println(localhost);

        NioEventLoopGroup group = new NioEventLoopGroup();
        try {
            List<InetSocketAddress> result =
                    DefaultAddressResolverGroup.INSTANCE
                            .getResolver(group.next())
                            .resolveAll(InetSocketAddress.createUnresolved("DESKTOP-BHE9K15", 80))
                            .get();
            System.out.println("Netty DefaultAddressResolverGroup " + result);

            DnsNameResolverBuilder builder = new DnsNameResolverBuilder(group.next())
                    .channelType(NioDatagramChannel.class);
            DnsNameResolver resolver = builder.build();
            resolver.resolveAll("DESKTOP-BHE9K15")
                    .get();
        }
        finally {
            group.shutdownGracefully();
        }
    }
}

when the above code is executed, the result is:

[DESKTOP-BHE9K15/IPv4, DESKTOP-BHE9K15/IPv6]
DESKTOP-BHE9K15/IPv4
Netty DefaultAddressResolverGroup [DESKTOP-BHE9K15/IPv4:80, DESKTOP-BHE9K15/[IPv6]:80]
Exception in thread "main" java.util.concurrent.ExecutionException: java.net.UnknownHostException: failed to resolve 'DESKTOP-BHE9K15' after 2 queries 

Netty version

4.1.63.Final

JVM version (e.g. java -version)

java 11

OS version (e.g. uname -a)

Windows 10

[violetagg]

@violetagg couldn’t we just call InetAddress.getLocalHost().getHostName() once in a static block ?

Yep and then apply the solution for localhost

[violetagg]

@violetagg can you do a PR ?

ok