Merge pull request #30952 from geoand/#30951

Disable Vertx DNS resolver when deploying to kubernetes

extensions/kubernetes-client/runtime-internal/src/main/java/io/quarkus/kubernetes/client/runtime/QuarkusHttpClientFactory.java

@@ -0,0 +1,62 @@
+package io.quarkus.kubernetes.client.runtime;
+
+import static io.vertx.core.spi.resolver.ResolverProvider.DISABLE_DNS_RESOLVER_PROP_NAME;
+
+import jakarta.enterprise.inject.spi.CDI;
+
+import io.fabric8.kubernetes.client.Config;
+import io.fabric8.kubernetes.client.http.HttpClient;
+import io.fabric8.kubernetes.client.vertx.VertxHttpClientBuilder;
+import io.vertx.core.Vertx;
+import io.vertx.core.VertxOptions;
+
+public class QuarkusHttpClientFactory implements HttpClient.Factory {
+
+    private Vertx vertx;
+
+    public QuarkusHttpClientFactory() {
+        // The client might get initialized outside a Quarkus context that can provide the Vert.x instance
+        // This is the case for the MockServer / @KubernetesTestServer where the server provides the KubernetesClient instance
+        try {
+            this.vertx = CDI.current().select(Vertx.class).get();
+        } catch (Exception e) {
+            this.vertx = createVertxInstance();
+        }
+    }
+
+    private Vertx createVertxInstance() {
+        // We must disable the async DNS resolver as it can cause issues when resolving the Vault instance.
+        // This is done using the DISABLE_DNS_RESOLVER_PROP_NAME system property.
+        // The DNS resolver used by vert.x is configured during the (synchronous) initialization.
+        // So, we just need to disable the async resolver around the Vert.x instance creation.
+        String originalValue = System.getProperty(DISABLE_DNS_RESOLVER_PROP_NAME);
+        Vertx vertx;
+        try {
+            System.setProperty(DISABLE_DNS_RESOLVER_PROP_NAME, "true");
+            vertx = Vertx.vertx(new VertxOptions());
+        } finally {
+            // Restore the original value
+            if (originalValue == null) {
+                System.clearProperty(DISABLE_DNS_RESOLVER_PROP_NAME);
+            } else {
+                System.setProperty(DISABLE_DNS_RESOLVER_PROP_NAME, originalValue);
+            }
+        }
+        return vertx;
+    }
+
+    @Override
+    public HttpClient.Builder newBuilder(Config config) {
+        return HttpClient.Factory.super.newBuilder(config);
+    }
+
+    @Override
+    public VertxHttpClientBuilder<QuarkusHttpClientFactory> newBuilder() {
+        return new VertxHttpClientBuilder<>(this, vertx);
+    }
+
+    @Override
+    public int priority() {
+        return 1;
+    }
+}