Generate Regional Endpoints (OPTION 2: CodeSection/Interceptor)

codegen/aws/core/src/main/java/software/amazon/smithy/python/aws/codegen/AwsStandardRegionalEndpointsIntegration.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.aws.codegen;
+
+import java.util.List;
+import software.amazon.smithy.aws.traits.ServiceTrait;
+import software.amazon.smithy.codegen.core.Symbol;
+import software.amazon.smithy.python.codegen.CodegenUtils;
+import software.amazon.smithy.python.codegen.ConfigProperty;
+import software.amazon.smithy.python.codegen.GenerationContext;
+import software.amazon.smithy.python.codegen.integrations.PythonIntegration;
+import software.amazon.smithy.python.codegen.integrations.RuntimeClientPlugin;
+import software.amazon.smithy.python.codegen.sections.EndpointParametersSection;
+import software.amazon.smithy.python.codegen.sections.EndpointResolverSection;
+import software.amazon.smithy.python.codegen.sections.InitDefaultEndpointResolverSection;
+import software.amazon.smithy.python.codegen.writer.PythonWriter;
+import software.amazon.smithy.utils.CodeInterceptor;
+import software.amazon.smithy.utils.CodeSection;
+
+public class AwsStandardRegionalEndpointsIntegration implements PythonIntegration {
+    @Override
+    public List<RuntimeClientPlugin> getClientPlugins(GenerationContext context) {
+        if (context.applicationProtocol().isHttpProtocol()) {
+            var region = ConfigProperty.builder()
+                    .name("region")
+                    .type(Symbol.builder().name("str").build())
+                    .documentation(" The AWS region to connect to. The configured region is used to "
+                            + "determine the service endpoint.")
+                    .build();
+            return List.of(
+                    RuntimeClientPlugin.builder()
+                            .addConfigProperty(region)
+                            .build());
+        } else {
+            return List.of();
+        }
+    }
+
+    @Override
+    public List<? extends CodeInterceptor<? extends CodeSection, PythonWriter>> interceptors(
+            GenerationContext context
+    ) {
+        return List.of(
+                new RegionalEndpointParametersInterceptor(context),
+                new RegionalEndpointResolverInterceptor(context),
+                new RegionalInitEndpointResolverInterceptor(context));
+    }
+
+    private static final class RegionalEndpointParametersInterceptor
+            implements CodeInterceptor<EndpointParametersSection, PythonWriter> {
+
+        private final GenerationContext context;
+
+        public RegionalEndpointParametersInterceptor(GenerationContext context) {
+            this.context = context;
+        }
+
+        @Override
+        public Class<EndpointParametersSection> sectionType() {
+            return EndpointParametersSection.class;
+        }
+
+        @Override
+        public void write(PythonWriter writer, String previousText, EndpointParametersSection section) {
+            var params = CodegenUtils.getEndpointParametersSymbol(context.settings());
+
+            writer.write("from smithy_aws_core.endpoints.standard_regional import RegionalEndpointParameters");
+            writer.write("$L = RegionalEndpointParameters", params.getName());
+        }
+    }
+
+    private static final class RegionalEndpointResolverInterceptor
+            implements CodeInterceptor<EndpointResolverSection, PythonWriter> {
+
+        private final GenerationContext context;
+
+        public RegionalEndpointResolverInterceptor(GenerationContext context) {
+            this.context = context;
+        }
+
+        @Override
+        public Class<EndpointResolverSection> sectionType() {
+            return EndpointResolverSection.class;
+        }
+
+        @Override
+        public void write(PythonWriter writer, String previousText, EndpointResolverSection section) {
+            var resolver = CodegenUtils.getEndpointResolverSymbol(context.settings());
+
+            writer.write("from smithy_aws_core.endpoints.standard_regional import StandardRegionalEndpointsResolver");
+            writer.write("$L = StandardRegionalEndpointsResolver", resolver.getName());
+        }
+    }
+
+    private static final class RegionalInitEndpointResolverInterceptor
+            implements CodeInterceptor<InitDefaultEndpointResolverSection, PythonWriter> {
+
+        private final GenerationContext context;
+
+        public RegionalInitEndpointResolverInterceptor(GenerationContext context) {
+            this.context = context;
+        }
+
+        @Override
+        public Class<InitDefaultEndpointResolverSection> sectionType() {
+            return InitDefaultEndpointResolverSection.class;
+        }
+
+        @Override
+        public void write(PythonWriter writer, String previousText, InitDefaultEndpointResolverSection section) {
+            var resolver = CodegenUtils.getEndpointResolverSymbol(context.settings());
+
+            String endpointPrefix = context.settings()
+                    .service(context.model())
+                    .getTrait(ServiceTrait.class)
+                    .map(ServiceTrait::getEndpointPrefix)
+                    .orElse(context.settings().service().getName());
+
+            writer.write("self.endpoint_resolver = endpoint_resolver or $T(endpoint_prefix=$S)",
+                    resolver,
+                    endpointPrefix);
+
+        }
+    }
+}

codegen/aws/core/src/main/resources/META-INF/services/software.amazon.smithy.python.codegen.integrations.PythonIntegration

@@ -6,3 +6,4 @@
 software.amazon.smithy.python.aws.codegen.AwsAuthIntegration
 software.amazon.smithy.python.aws.codegen.AwsProtocolsIntegration
 software.amazon.smithy.python.aws.codegen.AwsUserAgentIntegration
+software.amazon.smithy.python.aws.codegen.AwsStandardRegionalEndpointsIntegration

codegen/core/src/main/java/software/amazon/smithy/python/codegen/ClientGenerator.java

@@ -443,16 +443,10 @@ async def _handle_attempt(
         if (context.applicationProtocol().isHttpProtocol()) {
             writer.addDependency(SmithyPythonDependency.SMITHY_CORE);
             writer.addDependency(SmithyPythonDependency.SMITHY_HTTP);
-            // TODO: implement the endpoints 2.0 spec and remove the hard-coded handling of static params.
-            writer.addImport("smithy_http.endpoints", "StaticEndpointParams");
             writer.addImport("smithy_core", "URI");
             writer.write("""
                             # Step 7f: Invoke endpoint_resolver.resolve_endpoint
-                            if config.endpoint_uri is None:
-                                raise $1T(
-                                    "No endpoint_uri found on the operation config."
-                                )
-                            endpoint_resolver_parameters = StaticEndpointParams(uri=config.endpoint_uri)
+                            endpoint_resolver_parameters = $1T.build(config=config)
                             logger.debug("Calling endpoint resolver with parameters: %s", endpoint_resolver_parameters)
                             endpoint = await config.endpoint_resolver.resolve_endpoint(
                                 endpoint_resolver_parameters
@@ -475,7 +469,8 @@ async def _handle_attempt(
                             )
                             context._transport_request.fields.extend(endpoint.headers)
 
-                    """, errorSymbol);
+                    """,
+                    CodegenUtils.getEndpointParametersSymbol(context.settings()));
         }
         writer.popState();
 

codegen/core/src/main/java/software/amazon/smithy/python/codegen/CodegenUtils.java

@@ -140,10 +140,38 @@ public static Symbol getUnknownApiError(PythonSettings settings) {
     }
 
     /**
-     * Gets the symbol for the http auth parameters object.
+     * Gets the symbol for the endpoint parameters object.
      *
      * @param settings The client settings, used to account for module configuration.
-     * @return Returns the symbol for http auth params.
+     * @return Returns the symbol for endpoint parameters.
+     */
+    public static Symbol getEndpointParametersSymbol(PythonSettings settings) {
+        return Symbol.builder()
+                .name("EndpointParameters")
+                .namespace(String.format("%s.endpoints", settings.moduleName()), ".")
+                .definitionFile(String.format("./%s/endpoints.py", settings.moduleName()))
+                .build();
+    }
+
+    /**
+     * Gets the symbol for the endpoint resolver object.
+     *
+     * @param settings The client settings, used to account for module configuration.
+     * @return Returns the symbol for endpoint resolver.
+     */
+    public static Symbol getEndpointResolverSymbol(PythonSettings settings) {
+        return Symbol.builder()
+                .name("EndpointResolver")
+                .namespace(String.format("%s.endpoints", settings.moduleName()), ".")
+                .definitionFile(String.format("./%s/endpoints.py", settings.moduleName()))
+                .build();
+    }
+
+    /**
+     * Gets the symbol for the http auth params.
+     *
+     * @param settings The client settings, used to account for module configuration.
+     * @return Returns the http auth params symbol.
      */
     public static Symbol getHttpAuthParamsSymbol(PythonSettings settings) {
         return Symbol.builder()

codegen/core/src/main/java/software/amazon/smithy/python/codegen/DirectedPythonClientCodegen.java

@@ -29,6 +29,7 @@
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.python.codegen.generators.ConfigGenerator;
+import software.amazon.smithy.python.codegen.generators.EndpointsGenerator;
 import software.amazon.smithy.python.codegen.generators.EnumGenerator;
 import software.amazon.smithy.python.codegen.generators.InitGenerator;
 import software.amazon.smithy.python.codegen.generators.IntEnumGenerator;
@@ -110,6 +111,7 @@ public void customizeBeforeShapeGeneration(CustomizeDirective<GenerationContext,
         if (directive.context().applicationProtocol().isHttpProtocol()
                 && !serviceIndex.getAuthSchemes(directive.service()).isEmpty()) {
             new HttpAuthGenerator(directive.context(), directive.settings()).run();
+            new EndpointsGenerator(directive.context(), directive.settings()).run();
         }
     }
 

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/ConfigGenerator.java

@@ -26,6 +26,7 @@
 import software.amazon.smithy.python.codegen.integrations.PythonIntegration;
 import software.amazon.smithy.python.codegen.integrations.RuntimeClientPlugin;
 import software.amazon.smithy.python.codegen.sections.ConfigSection;
+import software.amazon.smithy.python.codegen.sections.InitDefaultEndpointResolverSection;
 import software.amazon.smithy.python.codegen.writer.PythonWriter;
 import software.amazon.smithy.utils.CodeInterceptor;
 import software.amazon.smithy.utils.SmithyInternalApi;
@@ -78,30 +79,6 @@ public final class ConfigGenerator implements Runnable {
                             .build())
                     .documentation("Configuration for individual HTTP requests.")
                     .build(),
-            ConfigProperty.builder()
-                    .name("endpoint_resolver")
-                    .type(Symbol.builder()
-                            .name("EndpointResolver[Any]")
-                            .addReference(Symbol.builder()
-                                    .name("Any")
-                                    .namespace("typing", ".")
-                                    .putProperty(SymbolProperties.STDLIB, true)
-                                    .build())
-                            .addReference(Symbol.builder()
-                                    .name("EndpointResolver")
-                                    .namespace("smithy_http.aio.interfaces", ".")
-                                    .addDependency(SmithyPythonDependency.SMITHY_HTTP)
-                                    .build())
-                            .build())
-                    .documentation("""
-                            The endpoint resolver used to resolve the final endpoint per-operation based on the \
-                            configuration.""")
-                    .nullable(false)
-                    .initialize(writer -> {
-                        writer.addImport("smithy_http.aio.endpoints", "StaticEndpointResolver");
-                        writer.write("self.endpoint_resolver = endpoint_resolver or StaticEndpointResolver()");
-                    })
-                    .build(),
             ConfigProperty.builder()
                     .name("endpoint_uri")
                     .type(Symbol.builder()
@@ -124,7 +101,7 @@ public ConfigGenerator(PythonSettings settings, GenerationContext context) {
     }
 
     private static List<ConfigProperty> getHttpProperties(GenerationContext context) {
-        var properties = new ArrayList<ConfigProperty>(HTTP_PROPERTIES.size() + 1);
+        var properties = new ArrayList<ConfigProperty>(HTTP_PROPERTIES.size() + 2);
         var clientBuilder = ConfigProperty.builder()
                 .name("http_client")
                 .type(Symbol.builder()
@@ -155,6 +132,25 @@ private static List<ConfigProperty> getHttpProperties(GenerationContext context)
         }
         properties.add(clientBuilder.build());
 
+        var endpointResolver = CodegenUtils.getEndpointResolverSymbol(context.settings());
+        properties.add(ConfigProperty.builder()
+                .name("endpoint_resolver")
+                .type(Symbol.builder()
+                        .name("_EndpointResolver[EndpointParameters]")
+                        .addReference(CodegenUtils.getEndpointParametersSymbol(context.settings()))
+                        .build())
+                .documentation("""
+                        The endpoint resolver used to resolve the final endpoint per-operation based on the \
+                        configuration.""")
+                .nullable(false)
+                .initialize(writer -> {
+                    writer.addImport("smithy_http.aio.interfaces", "EndpointResolver", "_EndpointResolver");
+                    writer.pushState(new InitDefaultEndpointResolverSection());
+                    writer.write("self.endpoint_resolver = endpoint_resolver or $T()", endpointResolver);
+                    writer.popState();
+                })
+                .build());
+
         properties.addAll(HTTP_PROPERTIES);
         return List.copyOf(properties);
     }

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/EndpointsGenerator.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.codegen.generators;
+
+import software.amazon.smithy.codegen.core.Symbol;
+import software.amazon.smithy.python.codegen.CodegenUtils;
+import software.amazon.smithy.python.codegen.GenerationContext;
+import software.amazon.smithy.python.codegen.PythonSettings;
+import software.amazon.smithy.python.codegen.SmithyPythonDependency;
+import software.amazon.smithy.python.codegen.sections.EndpointParametersSection;
+import software.amazon.smithy.python.codegen.sections.EndpointResolverSection;
+import software.amazon.smithy.python.codegen.writer.PythonWriter;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * This class is responsible for generating the endpoint resolver and its parameters.
+ */
+@SmithyInternalApi
+public final class EndpointsGenerator implements Runnable {
+
+    private final PythonSettings settings;
+    private final GenerationContext context;
+
+    public EndpointsGenerator(GenerationContext context, PythonSettings settings) {
+        this.context = context;
+        this.settings = settings;
+    }
+
+    @Override
+    public void run() {
+        var params = CodegenUtils.getEndpointParametersSymbol(settings);
+        context.writerDelegator().useFileWriter(params.getDefinitionFile(), params.getNamespace(), writer -> {
+            generateEndpointParameters(writer, params);
+        });
+
+        var resolver = CodegenUtils.getEndpointResolverSymbol(settings);
+        context.writerDelegator().useFileWriter(resolver.getDefinitionFile(), resolver.getNamespace(), writer -> {
+            generateEndpointResolver(writer, resolver);
+        });
+    }
+
+    private void generateEndpointParameters(PythonWriter writer, Symbol params) {
+        writer.pushState(new EndpointParametersSection());
+        writer.addDependency(SmithyPythonDependency.SMITHY_HTTP);
+        writer.write("from smithy_http.endpoints import StaticEndpointParams");
+        writer.write("$L = StaticEndpointParams", params.getName());
+        writer.popState();
+    }
+
+    private void generateEndpointResolver(PythonWriter writer, Symbol resolver) {
+        writer.pushState(new EndpointResolverSection());
+        writer.addDependency(SmithyPythonDependency.SMITHY_HTTP);
+        writer.write("from smithy_http.aio.endpoints import StaticEndpointResolver");
+        writer.write("$L = StaticEndpointResolver", resolver.getName());
+        writer.popState();
+    }
+}

codegen/core/src/main/java/software/amazon/smithy/python/codegen/sections/EndpointParametersSection.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.codegen.sections;
+
+import software.amazon.smithy.utils.CodeSection;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * A section that controls generating the EndpointParameters class.
+ */
+@SmithyInternalApi
+public record EndpointParametersSection() implements CodeSection {}

codegen/core/src/main/java/software/amazon/smithy/python/codegen/sections/EndpointResolverSection.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.codegen.sections;
+
+import software.amazon.smithy.utils.CodeSection;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * A section that controls generating the EndpointResolver class.
+ */
+@SmithyInternalApi
+public record EndpointResolverSection() implements CodeSection {}

codegen/core/src/main/java/software/amazon/smithy/python/codegen/sections/InitDefaultEndpointResolverSection.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.codegen.sections;
+
+import software.amazon.smithy.utils.CodeSection;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * A section that controls generating the EndpointParameters class.
+ */
+@SmithyInternalApi
+public record InitDefaultEndpointResolverSection() implements CodeSection {}

packages/smithy-aws-core/src/smithy_aws_core/endpoints/__init__.py

@@ -0,0 +1,2 @@
+#  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#  SPDX-License-Identifier: Apache-2.0