doc: document how to Disable hostname verification in ssl config

http-client/src/main/java/io/micronaut/http/client/netty/ssl/NettyClientSslBuilder.java

@@ -88,6 +88,14 @@ public final Optional<SslContext> build(SslConfiguration ssl, HttpVersion httpVe
     @NonNull
     @Override
     public final SslContext build(SslConfiguration ssl, HttpVersionSelection versionSelection) {
+        try {
+            return createSslContextBuilder(ssl, versionSelection).build();
+        } catch (SSLException ex) {
+            throw new SslConfigurationException("An error occurred while setting up SSL", ex);
+        }
+    }
+
+    protected SslContextBuilder createSslContextBuilder(SslConfiguration ssl, HttpVersionSelection versionSelection) {
         SslContextBuilder sslBuilder = SslContextBuilder
             .forClient()
             .keyManager(getKeyManagerFactory(ssl))
@@ -122,12 +130,7 @@ public final SslContext build(SslConfiguration ssl, HttpVersionSelection version
                 versionSelection.getAlpnSupportedProtocols()
             ));
         }
-
-        try {
-            return sslBuilder.build();
-        } catch (SSLException ex) {
-            throw new SslConfigurationException("An error occurred while setting up SSL", ex);
-        }
+        return sslBuilder;
     }
 
     @Override

http-client/src/test/java/io/micronaut/http/client/netty/ssl/NettyClientSslBuilderReplacement.java

@@ -0,0 +1,30 @@
+package io.micronaut.http.client.netty.ssl;
+
+import io.micronaut.context.annotation.BootstrapContextCompatible;
+import io.micronaut.context.annotation.Replaces;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.context.annotation.Secondary;
+import io.micronaut.context.env.Environment;
+import io.micronaut.core.io.ResourceResolver;
+import io.micronaut.http.client.HttpVersionSelection;
+import io.micronaut.http.ssl.SslConfiguration;
+import io.netty.handler.ssl.SslContextBuilder;
+import jakarta.inject.Singleton;
+
+@Requires(env = Environment.TEST)
+@Singleton
+@BootstrapContextCompatible
+@Secondary
+@Replaces(NettyClientSslBuilder.class)
+class NettyClientSslBuilderReplacement extends NettyClientSslBuilder {
+    NettyClientSslBuilderReplacement(ResourceResolver resourceResolver) {
+        super(resourceResolver);
+    }
+
+    @Override
+    protected SslContextBuilder createSslContextBuilder(SslConfiguration ssl, HttpVersionSelection versionSelection) {
+        SslContextBuilder builder = super.createSslContextBuilder(ssl, versionSelection);
+        builder.endpointIdentificationAlgorithm(null);
+        return builder;
+    }
+}

src/main/docs/guide/httpClient/httpClientImplementations/nettyHttpClient.adoc

@@ -1,3 +1,15 @@
 To use an implementation based on https://netty.io[Netty], add the following dependency to your build:
 
 dependency:micronaut-http-client[]
+
+== Disable hostname verification in ssl config
+
+It may be necessary in a testing or development environment to disable hostname verification.
+
+To disable hostname verification in your test classpath, you could create a <<replaces, Bean Replacement>> in `src/test/java`:
+
+[source,java]
+----
+include::http-client/src/test/java/io/micronaut/http/client/netty/ssl/NettyClientSslBuilderReplacement.java[indent=0]
+----
+WARNING: Disabling host name verification leaves your application potentially vulnerable to Man-in-the-Middle attacks and should only be done with the utmost care typically only in a development / testing environment. Never disable host name verification in production or in a scenario where you are making remote calls over the internet.