Resolve host prefix injection setting from env/config

.changes/next-release/feature-AWSSDKforJavav2-eeeef1c.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Add support for resolving the disable host prefix injection setting from the aws.disableHostPrefixInjection system property, the AWS_DISABLE_HOST_PREFIX_INJECTION environment variable, and the disable_host_prefix_injection profile property."
+}

core/aws-core/src/main/java/software/amazon/awssdk/awscore/client/builder/AwsDefaultClientBuilder.java

@@ -48,7 +48,6 @@
 import software.amazon.awssdk.awscore.retry.AwsRetryStrategy;
 import software.amazon.awssdk.core.ClientEndpointProvider;
 import software.amazon.awssdk.core.client.builder.SdkDefaultClientBuilder;
-import software.amazon.awssdk.core.client.config.SdkAdvancedClientOption;
 import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
 import software.amazon.awssdk.core.client.config.SdkClientOption;
 import software.amazon.awssdk.core.http.EnableDefaultSocketTimeout2026Resolver;
@@ -146,7 +145,6 @@ protected AwsDefaultClientBuilder() {
     protected final SdkClientConfiguration mergeChildDefaults(SdkClientConfiguration configuration) {
         SdkClientConfiguration config = mergeServiceDefaults(configuration);
         config = config.merge(c -> c.option(AwsAdvancedClientOption.ENABLE_DEFAULT_REGION_DETECTION, true)
-                                    .option(SdkAdvancedClientOption.DISABLE_HOST_PREFIX_INJECTION, false)
                                     .option(AwsClientOption.SERVICE_SIGNING_NAME, signingName())
                                     .option(SdkClientOption.SERVICE_NAME, serviceName())
                                     .option(AwsClientOption.ENDPOINT_PREFIX, serviceEndpointPrefix()));

core/aws-core/src/test/java/software/amazon/awssdk/awscore/client/builder/DefaultAwsClientBuilderTest.java

@@ -25,6 +25,7 @@
 import static software.amazon.awssdk.awscore.client.config.AwsAdvancedClientOption.ENABLE_DEFAULT_REGION_DETECTION;
 import static software.amazon.awssdk.awscore.client.config.AwsClientOption.SERVICE_SIGNING_NAME;
 import static software.amazon.awssdk.awscore.client.config.AwsClientOption.SIGNING_REGION;
+import static software.amazon.awssdk.core.client.config.SdkAdvancedClientOption.DISABLE_HOST_PREFIX_INJECTION;
 import static software.amazon.awssdk.core.client.config.SdkAdvancedClientOption.SIGNER;
 
 import java.beans.BeanInfo;
@@ -37,6 +38,7 @@
 import java.util.Optional;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -53,6 +55,7 @@
 import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
 import software.amazon.awssdk.core.client.config.SdkClientOption;
 import software.amazon.awssdk.core.ClientEndpointProvider;
+import software.amazon.awssdk.core.SdkSystemSetting;
 import software.amazon.awssdk.core.internal.retry.SdkDefaultRetryStrategy;
 import software.amazon.awssdk.core.signer.Signer;
 import software.amazon.awssdk.http.SdkHttpClient;
@@ -99,6 +102,32 @@ public class DefaultAwsClientBuilderTest {
     public void setup() {
         when(defaultHttpClientBuilder.buildWithDefaults(any())).thenReturn(mock(SdkHttpClient.class));
         when(defaultAsyncHttpClientFactory.buildWithDefaults(any())).thenReturn(mock(SdkAsyncHttpClient.class));
+        System.clearProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property());
+    }
+
+    @AfterEach
+    public void cleanup() {
+        System.clearProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property());
+    }
+
+    @Test
+    public void disableHostPrefixInjection_nothingSet_defaultsToFalse() {
+        TestClient client = testClientBuilder().region(Region.US_WEST_1).build();
+        assertThat(client.clientConfiguration.option(DISABLE_HOST_PREFIX_INJECTION)).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_systemPropertyTrue_resolvesTrue() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "true");
+        TestClient client = testClientBuilder().region(Region.US_WEST_1).build();
+        assertThat(client.clientConfiguration.option(DISABLE_HOST_PREFIX_INJECTION)).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_asyncClient_systemPropertyTrue_resolvesTrue() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "true");
+        TestAsyncClient client = testAsyncClientBuilder().region(Region.US_WEST_1).build();
+        assertThat(client.clientConfiguration.option(DISABLE_HOST_PREFIX_INJECTION)).isTrue();
     }
 
     @Test

core/profiles/src/main/java/software/amazon/awssdk/profiles/ProfileProperty.java

@@ -177,6 +177,12 @@ public final class ProfileProperty {
      */
     public static final String DISABLE_REQUEST_COMPRESSION = "disable_request_compression";
 
+    /**
+     * Whether the SDK should skip prepending the modeled hostPrefix to the endpoint host. The default value is false, i.e.,
+     * the hostPrefix is prepended.
+     */
+    public static final String DISABLE_HOST_PREFIX_INJECTION = "disable_host_prefix_injection";
+
     /**
      * The minimum compression size in bytes, inclusive, for a request to be compressed. The default value is 10_240.
      * The value must be non-negative and no greater than 10_485_760.

core/sdk-core/src/main/java/software/amazon/awssdk/core/SdkSystemSetting.java

@@ -230,6 +230,12 @@ public enum SdkSystemSetting implements SystemSetting {
      */
     AWS_DISABLE_REQUEST_COMPRESSION("aws.disableRequestCompression", null),
 
+    /**
+     * Whether the SDK should skip prepending the modeled hostPrefix to the endpoint host. The default value is false, i.e.,
+     * the hostPrefix is prepended.
+     */
+    AWS_DISABLE_HOST_PREFIX_INJECTION("aws.disableHostPrefixInjection", null),
+
     /**
      * Defines the minimum compression size in bytes, inclusive, for a request to be compressed. The default value is 10_240.
      * The value must be non-negative and no greater than 10_485_760.

core/sdk-core/src/main/java/software/amazon/awssdk/core/client/builder/SdkDefaultClientBuilder.java

@@ -18,6 +18,7 @@
 import static software.amazon.awssdk.core.ClientType.ASYNC;
 import static software.amazon.awssdk.core.ClientType.SYNC;
 import static software.amazon.awssdk.core.client.config.SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR;
+import static software.amazon.awssdk.core.client.config.SdkAdvancedClientOption.DISABLE_HOST_PREFIX_INJECTION;
 import static software.amazon.awssdk.core.client.config.SdkAdvancedClientOption.USER_AGENT_PREFIX;
 import static software.amazon.awssdk.core.client.config.SdkAdvancedClientOption.USER_AGENT_SUFFIX;
 import static software.amazon.awssdk.core.client.config.SdkClientOption.ADDITIONAL_HTTP_HEADERS;
@@ -360,7 +361,8 @@ private SdkClientConfiguration finalizeConfiguration(SdkClientConfiguration conf
                      .option(EXECUTION_INTERCEPTORS, resolveExecutionInterceptors(config))
                      .lazyOption(CLIENT_USER_AGENT, this::resolveClientUserAgent)
                      .lazyOption(COMPRESSION_CONFIGURATION, this::resolveCompressionConfiguration)
-                     .lazyOptionIfAbsent(IDENTITY_PROVIDERS, c -> IdentityProviders.builder().build());
+                     .lazyOptionIfAbsent(IDENTITY_PROVIDERS, c -> IdentityProviders.builder().build())
+                     .lazyOptionIfAbsent(DISABLE_HOST_PREFIX_INJECTION, this::resolveDisableHostPrefixInjection);
         builder.computeOptionIfAbsent(HTTP_CLIENT_CONFIG_TYPE, () -> BusinessMetricFeatureId.HTTP_CLIENT_AUTO);
         return builder.build();
     }
@@ -390,6 +392,17 @@ private Boolean resolveCompressionEnabled(LazyValueSource config, CompressionCon
                             .orElse(true);
     }
 
+    private Boolean resolveDisableHostPrefixInjection(LazyValueSource config) {
+        Supplier<Optional<Boolean>> profileFileConfiguration =
+            () -> config.get(PROFILE_FILE_SUPPLIER).get()
+                        .profile(config.get(PROFILE_NAME))
+                        .flatMap(p -> p.booleanProperty(ProfileProperty.DISABLE_HOST_PREFIX_INJECTION));
+
+        return OptionalUtils.firstPresent(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.getBooleanValue(),
+                                          profileFileConfiguration)
+                            .orElse(false);
+    }
+
     private Integer resolveMinCompressionThreshold(LazyValueSource config, CompressionConfiguration compressionConfig) {
         Supplier<Optional<Integer>> systemSettingConfiguration =
             SdkSystemSetting.AWS_REQUEST_MIN_COMPRESSION_SIZE_BYTES::getIntegerValue;

core/sdk-core/src/main/java/software/amazon/awssdk/core/client/config/SdkAdvancedClientOption.java

@@ -84,6 +84,14 @@ public class SdkAdvancedClientOption<T> extends ClientOption<T> {
      * the endpoint host that the API request is sent to.
      *
      * Customers can set this value to True to disable the behavior.
+     *
+     * <p>If this option is not set, the SDK resolves it from the following sources, in order:
+     * <ol>
+     * <li>The {@code aws.disableHostPrefixInjection} system property</li>
+     * <li>The {@code AWS_DISABLE_HOST_PREFIX_INJECTION} environment variable</li>
+     * <li>The {@code disable_host_prefix_injection} property in the configured profile</li>
+     * </ol>
+     * If none of them is set, the default is false.
      */
     public static final SdkAdvancedClientOption<Boolean> DISABLE_HOST_PREFIX_INJECTION =
         new SdkAdvancedClientOption<>(Boolean.class);

core/sdk-core/src/test/java/software/amazon/awssdk/core/client/builder/DefaultClientBuilderTest.java

@@ -63,6 +63,7 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.function.Supplier;
 import org.assertj.core.api.Assertions;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -72,6 +73,7 @@
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 import software.amazon.awssdk.core.ClientEndpointProvider;
+import software.amazon.awssdk.core.SdkSystemSetting;
 import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
 import software.amazon.awssdk.core.client.config.SdkAdvancedClientOption;
 import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
@@ -89,6 +91,7 @@
 import software.amazon.awssdk.metrics.MetricCollection;
 import software.amazon.awssdk.metrics.MetricPublisher;
 import software.amazon.awssdk.profiles.ProfileFile;
+import software.amazon.awssdk.testutils.EnvironmentVariableHelper;
 import software.amazon.awssdk.utils.AttributeMap;
 import software.amazon.awssdk.utils.StringInputStream;
 
@@ -111,6 +114,9 @@ public class DefaultClientBuilderTest {
     @Rule
     public TemporaryFolder tempFolder = new TemporaryFolder();
 
+    @Rule
+    public EnvironmentVariableHelper environmentVariableHelper = new EnvironmentVariableHelper();
+
     @Mock
     private SdkHttpClient.Builder defaultHttpClientFactory;
 
@@ -121,6 +127,12 @@ public class DefaultClientBuilderTest {
     public void setup() {
         when(defaultHttpClientFactory.buildWithDefaults(any())).thenReturn(mock(SdkHttpClient.class));
         when(defaultAsyncHttpClientFactory.buildWithDefaults(any())).thenReturn(mock(SdkAsyncHttpClient.class));
+        System.clearProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property());
+    }
+
+    @After
+    public void cleanup() {
+        System.clearProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property());
     }
 
     @Test
@@ -520,6 +532,108 @@ public void defaultProfileFileSupplier_isStaticOrHasIdentityCaching() {
         assertThat(secondGet).isSameAs(firstGet);
     }
 
+    @Test
+    public void disableHostPrefixInjection_nothingSet_defaultsToFalse() {
+        assertThat(disableHostPrefixInjection(null, null)).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_asyncClient_nothingSet_defaultsToFalse() {
+        SdkClientConfiguration config = testAsyncClientBuilder()
+            .overrideConfiguration(o -> o.defaultProfileFile(profileFile(""))
+                                         .defaultProfileName("p"))
+            .build().clientConfiguration;
+        assertThat(config.option(DISABLE_HOST_PREFIX_INJECTION)).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_systemPropertyTrue_resolvesTrue() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "TRUE");
+        assertThat(disableHostPrefixInjection(null, null)).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_asyncClient_systemPropertyTrue_resolvesTrue() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "true");
+        SdkClientConfiguration config = testAsyncClientBuilder().build().clientConfiguration;
+        assertThat(config.option(DISABLE_HOST_PREFIX_INJECTION)).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_envVarTrue_resolvesTrue() {
+        environmentVariableHelper.set(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION, "true");
+        assertThat(disableHostPrefixInjection(null, null)).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_profileTrue_resolvesTrue() {
+        assertThat(disableHostPrefixInjection(null, "[profile p]\ndisable_host_prefix_injection = True")).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_profileTrueInOtherProfile_isIgnored() {
+        assertThat(disableHostPrefixInjection(null, "[profile other]\ndisable_host_prefix_injection = true")).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_explicitFalse_beatsSystemProperty() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "true");
+        assertThat(disableHostPrefixInjection(Boolean.FALSE, null)).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_explicitTrue_beatsSystemProperty() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "false");
+        assertThat(disableHostPrefixInjection(Boolean.TRUE, null)).isTrue();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_systemPropertyFalse_beatsEnvVar() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "false");
+        environmentVariableHelper.set(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION, "true");
+        assertThat(disableHostPrefixInjection(null, null)).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_envVarFalse_beatsProfile() {
+        environmentVariableHelper.set(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION, "false");
+        assertThat(disableHostPrefixInjection(null, "[profile p]\ndisable_host_prefix_injection = true")).isFalse();
+    }
+
+    @Test
+    public void disableHostPrefixInjection_invalidSystemProperty_throwsOnBuild() {
+        System.setProperty(SdkSystemSetting.AWS_DISABLE_HOST_PREFIX_INJECTION.property(), "yes");
+        assertThatThrownBy(() -> disableHostPrefixInjection(null, null)).isInstanceOf(IllegalStateException.class);
+    }
+
+    @Test
+    public void disableHostPrefixInjection_invalidProfileValue_throwsOnBuild() {
+        assertThatThrownBy(() -> disableHostPrefixInjection(null, "[profile p]\ndisable_host_prefix_injection = yes"))
+            .isInstanceOf(IllegalStateException.class);
+    }
+
+    private Boolean disableHostPrefixInjection(Boolean explicitValue, String profileContent) {
+        ClientOverrideConfiguration.Builder overrideConfig =
+            ClientOverrideConfiguration.builder()
+                                       .putAdvancedOption(SIGNER, TEST_SIGNER)
+                                       .defaultProfileFile(profileFile(profileContent == null ? "" : profileContent))
+                                       .defaultProfileName("p");
+        if (explicitValue != null) {
+            overrideConfig.putAdvancedOption(DISABLE_HOST_PREFIX_INJECTION, explicitValue);
+        }
+        return new TestClientBuilder().overrideConfiguration(overrideConfig.build())
+                                      .build()
+                                      .clientConfiguration
+                                      .option(DISABLE_HOST_PREFIX_INJECTION);
+    }
+
+    private static ProfileFile profileFile(String content) {
+        return ProfileFile.builder()
+                          .content(new StringInputStream(content))
+                          .type(ProfileFile.Type.CONFIGURATION)
+                          .build();
+    }
+
     private SdkDefaultClientBuilder<TestClientBuilder, TestClient> testClientBuilder() {
         ClientOverrideConfiguration overrideConfig =
                 ClientOverrideConfiguration.builder()