fix:fix admin http server no match but return 200. (#618)

(cherry picked from commit 8a85eaa)

Author: SkyeBeFreeman

polaris-plugins/polaris-plugin-api/src/main/java/com/tencent/polaris/api/plugin/compose/Extensions.java

@@ -52,6 +52,7 @@
 import com.tencent.polaris.api.utils.IPAddressUtils;
 import com.tencent.polaris.api.utils.MapUtils;
 import com.tencent.polaris.client.pojo.Node;
+import com.tencent.polaris.client.util.HttpServerUtils;
 import com.tencent.polaris.client.util.NamedThreadFactory;
 import com.tencent.polaris.client.util.Utils;
 import com.tencent.polaris.logging.LoggerFactory;
@@ -393,6 +394,10 @@ public void initHttpServer(Configuration configuration, Supplier plugins) {
             for (Map.Entry<String, HttpHandler> handlerEntry : allHandlers.entrySet()) {
                 httpServer.createContext(handlerEntry.getKey(), handlerEntry.getValue());
             }
+            // 设置默认处理器处理所有其他路径
+            httpServer.createContext("/", exchange -> {
+                HttpServerUtils.writeTextToHttpServer(exchange, "", 404);
+            });
             NamedThreadFactory threadFactory = new NamedThreadFactory("polaris-java-http");
             ExecutorService executor = Executors.newFixedThreadPool(3, threadFactory);
             httpServer.setExecutor(executor);

polaris-plugins/polaris-plugins-observability/stat-prometheus/src/main/java/com/tencent/polaris/plugins/stat/prometheus/plugin/PrometheusReporter.java

@@ -266,7 +266,6 @@ private void startScheduleAggregationTask() {
         }
         handlers = new HashMap<>();
         HttpMetricHandler metricHandler = new HttpMetricHandler(promRegistry);
-        handlers.put("/", metricHandler);
         handlers.put("/-/healthy", metricHandler);
         path = config.getPath();
         if (StringUtils.isBlank(path)) {