Netty Connector proxy handler to support JDK's options

[olotenko]

JDK's proxy handling supports a range of options, like -Dhttp.proxyHost=11.11.69.53 or -Dhttp.nonProxyHosts=*.lan|localhost|127.*|docker.for.mac.localhost|*.|*.default

It is easy to add this support using JDK's Proxy API. A patch showcasing its use by Netty Connector is attached.
netty_proxy_opts.zip

This patch will support the options, if no PROXY is specified explicitly.

[jansupol]

Goy an internal review:

I was the one to test the jersey-netty-connector code. I pulled his code changes and tested it in my local OKE environment. Proxy is set using -Dhttp.proxyHost and -Dhttp.proxyPort properties. I was unable to make any outbound invocation. (edited)

{
  "level": "ERROR",
  "logger": "oic.gen3.adapter.adapter-runtime.AsyncOutboundRequestHandler",
  "thread": "adapter-outbound-executor-thread-9",
  "ts": 1647383475086,
  "msg": "rootCauseException:
java.nio.channels.UnresolvedAddressException: null
  at java.base/sun.nio.ch.Net.checkAddress(Net.java:130)
  at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:675)
  at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:91)
  at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:88)
  at java.base/java.security.AccessController.doPrivileged(Native Method)
  at io.netty.util.internal.SocketUtils.connect(SocketUtils.java:88)
  at io.netty.channel.socket.nio.NioSocketChannel.doConnect(NioSocketChannel.java:315)
  at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:248)
  at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1342)
  at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
  at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.connect(CombinedChannelDuplexHandler.java:495)
  at io.netty.channel.ChannelOutboundHandlerAdapter.connect(ChannelOutboundHandlerAdapter.java:51)
  at io.netty.channel.CombinedChannelDuplexHandler.connect(CombinedChannelDuplexHandler.java:296)
  at io.netty.handler.proxy.HttpProxyHandler$HttpClientCodecWrapper.connect(HttpProxyHandler.java:299)
  at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
  at io.netty.handler.proxy.ProxyHandler.connect(ProxyHandler.java:178)
  at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
  at io.netty.handler.ssl.SslHandler.connect(SslHandler.java:713)
  at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
  at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.connect(CombinedChannelDuplexHandler.java:495)
  at io.netty.channel.ChannelOutboundHandlerAdapter.connect(ChannelOutboundHandlerAdapter.java:51)
  at io.netty.channel.CombinedChannelDuplexHandler.connect(CombinedChannelDuplexHandler.java:296)
  at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
  at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:517)
  at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:978)
  at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:265)
  at io.netty.bootstrap.Bootstrap$3.run(Bootstrap.java:250)
  at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
  at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500)
  at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
  at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
  at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
  at java.base/java.lang.Thread.run(Thread.java:834)
",
  "rep.fid": "nJVglqSvEeypL6VYz08Lww",
  "oic.service-instance": "...",
  "oic.trace": "bee05fc9557193d2bcfcb5014fbd254c",
  "oic.partition": "0",
  "opc-request-id": "/D10118EA8F7713835600E6840857EBD9",
  "oic.user": "..."
}

ProxySelector sel = ProxySelector.getDefault();
for (Proxy proxy : sel.select(requestUri)) {
    if (proxy.type().equals(Proxy.Type.HTTP)) {
        SocketAddress proxyAddress = proxy.address();

        if (proxy.address() instanceof InetSocketAddress) {
            InetSocketAddress isa = (InetSocketAddress) proxy.address();
            proxyAddress = isa;
            if (isa.isUnresolved()) {
                proxyAddress = new InetSocketAddress(isa.getHostString(), isa.getPort());
            }
        }
        p.addLast(new HttpProxyHandler(proxyAddress));
        break;
    }
}