WIP - add user agent interceptor/plugin

Author: alextwoods

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

@@ -0,0 +1,26 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.aws.codegen;
+
+import software.amazon.smithy.python.codegen.PythonDependency;
+import software.amazon.smithy.utils.SmithyUnstableApi;
+
+/**
+ * AWS Dependencies used in the smithy python generator.
+ */
+@SmithyUnstableApi
+public class AwsPythonDependency {
+    /**
+     * The core aws smithy runtime python package.
+     *
+     * <p>While in development this will use the develop branch.
+     */
+    public static final PythonDependency SMITHY_AWS_CORE = new PythonDependency(
+            "smithy_aws_core",
+            // You'll need to locally install this before we publish
+            "==0.0.1",
+            PythonDependency.Type.DEPENDENCY,
+            false);
+}

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

@@ -0,0 +1,45 @@
+/*
+ * 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.Collections;
+import java.util.List;
+import software.amazon.smithy.codegen.core.Symbol;
+import software.amazon.smithy.codegen.core.SymbolReference;
+import software.amazon.smithy.python.codegen.ConfigProperty;
+import software.amazon.smithy.python.codegen.integrations.PythonIntegration;
+import software.amazon.smithy.python.codegen.integrations.RuntimeClientPlugin;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * Adds a runtime plugin to set user agent.
+ */
+@SmithyInternalApi
+public class AwsUserAgentIntegration implements PythonIntegration {
+    @Override
+    public List<RuntimeClientPlugin> getClientPlugins() {
+        return List.of(
+                RuntimeClientPlugin.builder()
+                        .addConfigProperty(ConfigProperty.builder()
+                                // TODO: This is the name used in boto, but potentially could be user_agent_prefix.  Depends on backwards compat strategy.
+                                .name("user_agent_extra")
+                                .documentation("Additional suffix to be added to the user agent")
+                                .type(Symbol.builder().name("str").build()) // TODO: Should common types like this be defined as constants somewhere?
+                                .nullable(true)
+                                .build())
+                        .pythonPlugin(
+                                SymbolReference.builder()
+                                        .symbol(Symbol.builder()
+                                                .namespace(AwsPythonDependency.SMITHY_AWS_CORE.packageName() + ".plugins", ".")
+                                                .name("user_agent_plugin")
+                                                .addDependency(AwsPythonDependency.SMITHY_AWS_CORE)
+                                                .build())
+                                        .build()
+                        )
+                        .build()
+        );
+    }
+
+}

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

@@ -5,3 +5,4 @@
 
 software.amazon.smithy.python.aws.codegen.AwsAuthIntegration
 software.amazon.smithy.python.aws.codegen.AwsProtocolsIntegration
+software.amazon.smithy.python.aws.codegen.AwsUserAgentIntegration

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

@@ -0,0 +1,12 @@
+# Copyright 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.

packages/smithy-aws-core/src/smithy_aws_core/interceptors/user_agent.py

@@ -0,0 +1,24 @@
+# Copyright 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.
+from smithy_core.interceptors import Interceptor, InterceptorContext, Request, TransportRequest
+from smithy_http.aio import HTTPRequest
+
+
+class UserAgentInterceptor(Interceptor):
+    """Adds UserAgent header to the Request before signing.
+    """
+    def modify_before_signing(
+            self, context: InterceptorContext[Request, None, HTTPRequest, None]
+    ) -> HTTPRequest:
+        print("Oh Hello here I am!")
+        return context.transport_request

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

@@ -0,0 +1,16 @@
+# Copyright 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.
+
+# TODO: Define a Protocol for Config w/ interceptor method?
+def user_agent_plugin(config: any) -> None:
+    config.interceptors.append()