Include message and bytes metrics in the status of the active MQTT connections.

broker/src/main/java/io/moquette/server/netty/metrics/BytesMetricsHandler.java

@@ -16,6 +16,7 @@
 package io.moquette.server.netty.metrics;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
@@ -63,4 +64,8 @@ public class BytesMetricsHandler extends ChannelDuplexHandler {
         m_collector.sumWroteBytes(metrics.wroteBytes());
         super.close(ctx, promise);
     }
+
+    public static BytesMetrics getBytesMetrics(Channel channel) {
+        return channel.attr(ATTR_KEY_METRICS).get();
+    }
 }

broker/src/main/java/io/moquette/server/netty/metrics/MessageMetricsHandler.java

@@ -15,6 +15,7 @@
  */
 package io.moquette.server.netty.metrics;
 
+import io.netty.channel.Channel;
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
@@ -62,4 +63,8 @@ public class MessageMetricsHandler extends ChannelDuplexHandler {
         m_collector.sumWroteMessages(metrics.messagesWrote());
         super.close(ctx, promise);
     }
+
+    public static MessageMetrics getMessageMetrics(Channel channel) {
+        return channel.attr(ATTR_KEY_METRICS).get();
+    }
 }