Add grpc netty keep-alive-time configuration option

extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/GrpcServerRecorder.java

@@ -35,6 +35,7 @@
 import io.quarkus.arc.Arc;
 import io.quarkus.grpc.runtime.config.GrpcConfiguration;
 import io.quarkus.grpc.runtime.config.GrpcServerConfiguration;
+import io.quarkus.grpc.runtime.config.GrpcServerNettyConfig;
 import io.quarkus.grpc.runtime.devmode.GrpcHotReplacementInterceptor;
 import io.quarkus.grpc.runtime.devmode.GrpcServerReloader;
 import io.quarkus.grpc.runtime.health.GrpcHealthStorage;
@@ -192,6 +193,14 @@ public void run() {
                 });
     }
 
+    private void applyNettySettings(GrpcServerConfiguration configuration, VertxServerBuilder builder) {
+        if (configuration.netty != null) {
+            GrpcServerNettyConfig config = configuration.netty;
+            config.keepAliveTime.ifPresent(duration -> builder.nettyBuilder()
+                    .keepAliveTime(duration.toNanos(), TimeUnit.NANOSECONDS));
+        }
+    }
+
     private void applyTransportSecurityConfig(GrpcServerConfiguration configuration, VertxServerBuilder builder) {
         if (configuration.transportSecurity != null) {
             File cert = configuration.transportSecurity.certificate
@@ -302,6 +311,8 @@ public void handle(HttpServerOptions options) {
 
         applyTransportSecurityConfig(configuration, builder);
 
+        applyNettySettings(configuration, builder);
+
         boolean reflectionServiceEnabled = configuration.enableReflectionService
                 || ProfileManager.getLaunchMode() == LaunchMode.DEVELOPMENT;
         List<GrpcServiceDefinition> toBeRegistered = collectServiceDefinitions(grpcContainer.getServices());

extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/config/GrpcServerConfiguration.java

@@ -79,4 +79,10 @@ public class GrpcServerConfiguration {
      */
     @ConfigItem(defaultValue = "1")
     public int instances;
+
+    /**
+     * Configures the netty server settings.
+     */
+    @ConfigItem
+    public GrpcServerNettyConfig netty;
 }

extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/config/GrpcServerNettyConfig.java

@@ -0,0 +1,20 @@
+package io.quarkus.grpc.runtime.config;
+
+import java.time.Duration;
+import java.util.Optional;
+
+import io.quarkus.runtime.annotations.ConfigGroup;
+import io.quarkus.runtime.annotations.ConfigItem;
+
+@SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+@ConfigGroup
+public class GrpcServerNettyConfig {
+
+    /**
+     * Sets a custom keep-alive duration. This configures the time before sending a `keepalive` ping
+     * when there is no read activity.
+     */
+    @ConfigItem
+    public Optional<Duration> keepAliveTime;
+
+}