S3/customizations pathstyle (aws#720)

codegen/smithy-aws-go-codegen/src/main/java/software/amazon/smithy/aws/go/codegen/customization/AwsCustomGoDependency.java

@@ -23,6 +23,7 @@
  */
 public final class AwsCustomGoDependency extends AwsGoDependency {
     public static final GoDependency DYNAMODB_CUSTOMIZATION = aws("service/dynamodb/internal/customizations", "ddbcust");
+    public static final GoDependency S3_CUSTOMIZATION = aws("service/s3/internal/customizations", "s3cust");
 
     private AwsCustomGoDependency() {
         super();

codegen/smithy-aws-go-codegen/src/main/java/software/amazon/smithy/aws/go/codegen/customization/S3UpdateEndpoint.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ *
+ *
+ */
+
+package software.amazon.smithy.aws.go.codegen.customization;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import software.amazon.smithy.aws.traits.ServiceTrait;
+import software.amazon.smithy.codegen.core.CodegenException;
+import software.amazon.smithy.codegen.core.SymbolProvider;
+import software.amazon.smithy.go.codegen.GoDelegator;
+import software.amazon.smithy.go.codegen.GoSettings;
+import software.amazon.smithy.go.codegen.GoWriter;
+import software.amazon.smithy.go.codegen.SymbolUtils;
+import software.amazon.smithy.go.codegen.integration.ConfigField;
+import software.amazon.smithy.go.codegen.integration.GoIntegration;
+import software.amazon.smithy.go.codegen.integration.MiddlewareRegistrar;
+import software.amazon.smithy.go.codegen.integration.RuntimeClientPlugin;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.MemberShape;
+import software.amazon.smithy.model.shapes.OperationShape;
+import software.amazon.smithy.model.shapes.ServiceShape;
+import software.amazon.smithy.model.shapes.StructureShape;
+import software.amazon.smithy.utils.ListUtils;
+
+/**
+ * S3UpdateEndpoint integration serves to apply customizations for S3 service,
+ * and modifies the resolved endpoint based on S3 client config or input shape values.
+ */
+public class S3UpdateEndpoint implements GoIntegration {
+    private static final String USE_PATH_STYLE_OPTION = "UsePathStyle";
+    private static final String UPDATE_ENDPOINT_ADDER = "addUpdateEndpointMiddleware";
+    private static final String UPDATE_ENDPOINT_INTERNAL_ADDER = "UpdateEndpoint";
+    private static final String GET_BUCKET_FROM_INPUT = "getBucketFromInput";
+
+    /**
+     * Gets the sort order of the customization from -128 to 127, with lowest
+     * executed first.
+     *
+     * @return Returns the sort order, defaults to -40.
+     */
+    @Override
+    public byte getOrder() {
+        return 127;
+    }
+
+    @Override
+    public void writeAdditionalFiles(
+            GoSettings settings,
+            Model model,
+            SymbolProvider symbolProvider,
+            GoDelegator goDelegator
+    ) {
+        ServiceShape service = settings.getService(model);
+        if (!isS3Service(model, service)) {
+            return;
+        }
+
+        goDelegator.useShapeWriter(service, this::writeMiddlewareHelper);
+
+        goDelegator.useShapeWriter(service, writer -> {
+            writeInputGetter(writer, model, symbolProvider, service);
+        });
+    }
+
+    private void writeInputGetter(GoWriter writer, Model model, SymbolProvider symbolProvider, ServiceShape service) {
+        writer.writeDocs("getBucketFromInput returns a boolean indicating if the input has a modeled bucket name, " +
+                " and a pointer to string denoting a provided bucket member value");
+        writer.openBlock("func getBucketFromInput(input interface{}) (*string, bool) {","}", ()-> {
+            writer.openBlock("switch i:= input.(type) {", "}", () -> {
+                service.getAllOperations().forEach((operationId)-> {
+                    OperationShape operation = model.expectShape(operationId, OperationShape.class);
+                    StructureShape input = model.expectShape(operation.getInput().get(), StructureShape.class);
+
+                    List<MemberShape> targetBucketShape = input.getAllMembers().values().stream()
+                            .filter(m -> m.getTarget().getName().equals("BucketName"))
+                            .collect(Collectors.toList());
+                    // if model has multiple top level shapes targeting `BucketName`, we throw a codegen exception
+                    if (targetBucketShape.size()>1) {
+                        throw new CodegenException("BucketName shape should be targeted by only one input member, found " +
+                                targetBucketShape.size() +" for Input shape: "+ input.getId());
+                    }
+
+                    if (!targetBucketShape.isEmpty()) {
+                        writer.write("case $P: return i.$L, true", symbolProvider.toSymbol(input), targetBucketShape.get(0).getMemberName());
+                    }
+                });
+                writer.write("default: return nil, false");
+            });
+        });
+    }
+
+    private void writeMiddlewareHelper(GoWriter writer) {
+        writer.openBlock("func $L(stack *middleware.Stack, options Options) {", "}", UPDATE_ENDPOINT_ADDER, () -> {
+            writer.write("$T(stack, $T{UsePathStyle: options.$L, GetBucketFromInput: $L})",
+                    SymbolUtils.createValueSymbolBuilder(UPDATE_ENDPOINT_INTERNAL_ADDER,
+                            AwsCustomGoDependency.S3_CUSTOMIZATION).build(),
+                    SymbolUtils.createValueSymbolBuilder(UPDATE_ENDPOINT_INTERNAL_ADDER + "Options",
+                            AwsCustomGoDependency.S3_CUSTOMIZATION).build(),
+                    USE_PATH_STYLE_OPTION,
+                    GET_BUCKET_FROM_INPUT
+            );
+        });
+        writer.insertTrailingNewline();
+    }
+
+    @Override
+    public List<RuntimeClientPlugin> getClientPlugins() {
+        return ListUtils.of(
+                // Add S3 config to use path style host addressing.
+                RuntimeClientPlugin.builder()
+                        .servicePredicate(S3UpdateEndpoint::isS3Service)
+                        .configFields(ListUtils.of(
+                                ConfigField.builder()
+                                        .name(USE_PATH_STYLE_OPTION)
+                                        .type(SymbolUtils.createValueSymbolBuilder("bool")
+                                                .putProperty(SymbolUtils.GO_UNIVERSE_TYPE, true)
+                                                .build())
+                                        .documentation("Allows you to enable the client to use path-style addressing, "
+                                                + "i.e., `https://s3.amazonaws.com/BUCKET/KEY`. By default, the S3 client "
+                                                + "will use virtual hosted bucket addressing when possible"
+                                                + "(`https://BUCKET.s3.amazonaws.com/KEY`).")
+                                        .build()
+                                ))
+                        .registerMiddleware(MiddlewareRegistrar.builder()
+                                .resolvedFunction(SymbolUtils.createValueSymbolBuilder(UPDATE_ENDPOINT_ADDER).build())
+                                .useClientOptions()
+                                .build())
+                        .build()
+        );
+    }
+
+    private static boolean isS3Service(Model model, ServiceShape service) {
+        return service.expectTrait(ServiceTrait.class).getSdkId().equalsIgnoreCase("S3");
+    }
+}

codegen/smithy-aws-go-codegen/src/main/resources/META-INF/services/software.amazon.smithy.go.codegen.integration.GoIntegration

@@ -8,3 +8,4 @@ software.amazon.smithy.aws.go.codegen.AwsIdempotencyTokenProvider
 software.amazon.smithy.aws.go.codegen.AwsClientUserAgent
 software.amazon.smithy.aws.go.codegen.AwsSdkServiceId
 software.amazon.smithy.aws.go.codegen.customization.DynamoDBValidateResponseChecksum
+software.amazon.smithy.aws.go.codegen.customization.S3UpdateEndpoint