Add User-Agent information (#11)

* Add User-Agent information

Send a user-agent http header when talking to Lambda's http server.
This is important for collecting usage metrics.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.5)
 set(CMAKE_CXX_STANDARD 11)
 project(aws-lambda-runtime
-    VERSION 0.1
+    VERSION 0.1.0
     LANGUAGES CXX)
 
 option(ENABLE_TESTS "Enables building the test project, requires AWS C++ SDK." OFF)
@@ -26,6 +26,7 @@ check_cxx_compiler_flag("-Wl,-flto" LTO_CAPABLE)
 add_library(${PROJECT_NAME}
     "src/logging.cpp"
     "src/runtime.cpp"
+    "${CMAKE_CURRENT_BINARY_DIR}/version.cpp"
     )
 
 target_include_directories(${PROJECT_NAME} PUBLIC
@@ -51,11 +52,11 @@ target_compile_options(${PROJECT_NAME} PRIVATE
     "-Wno-sign-conversion")
 
 if (LOG_VERBOSITY)
-    target_compile_definitions(${PROJECT_NAME} PRIVATE "-DAWS_LAMBDA_LOG=${LOG_VERBOSITY}")
+    target_compile_definitions(${PROJECT_NAME} PRIVATE "AWS_LAMBDA_LOG=${LOG_VERBOSITY}")
 elseif(CMAKE_BUILD_TYPE STREQUAL Debug)
-    target_compile_definitions(${PROJECT_NAME} PRIVATE "-DAWS_LAMBDA_LOG=3")
+    target_compile_definitions(${PROJECT_NAME} PRIVATE "AWS_LAMBDA_LOG=3")
 else ()
-    target_compile_definitions(${PROJECT_NAME} PRIVATE "-DAWS_LAMBDA_LOG=0")
+    target_compile_definitions(${PROJECT_NAME} PRIVATE "AWS_LAMBDA_LOG=0")
 endif()
 
 if ((BUILD_SHARED_LIBS) AND (LTO_CAPABLE))
@@ -69,8 +70,14 @@ if (ENABLE_TESTS)
     add_subdirectory(tests)
 endif()
 
+#versioning
+configure_file(
+    "${CMAKE_CURRENT_SOURCE_DIR}/src/version.cpp.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/version.cpp"
+    NEWLINE_STYLE LF)
+
 # installation
-install(FILES "include/aws/lambda-runtime/runtime.h"
+install(FILES "include/aws/lambda-runtime/runtime.h" "include/aws/lambda-runtime/version.h"
     DESTINATION "include/aws/lambda-runtime")
 
 install(FILES "include/aws/logging/logging.h"

ci/codebuild/build-cpp-sdk.sh

@@ -11,7 +11,7 @@ cmake .. -GNinja -DBUILD_ONLY="lambda" \
     -DCMAKE_BUILD_TYPE=Release \
     -DENABLE_UNITY_BUILD=ON \
     -DBUILD_SHARED_LIBS=ON \
-    -DAUTORUN_UNIT_TESTS=OFF \
+    -DENABLE_TESTING=OFF \
     -DCMAKE_INSTALL_PREFIX=/install $@
 ninja
 ninja install

include/aws/lambda-runtime/version.h

@@ -0,0 +1,41 @@
+#pragma once
+/*
+ * Copyright 2018-present 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.
+ */
+
+namespace aws {
+namespace lambda_runtime {
+
+/**
+ * Returns the major component of the library version.
+ */
+unsigned get_version_major();
+
+/**
+ * Returns the minor component of the library version.
+ */
+unsigned get_version_minor();
+
+/**
+ * Returns the patch component of the library version.
+ */
+unsigned get_version_patch();
+
+/**
+ * Returns the semantic version of the library in the form Major.Minor.Patch
+ */
+char const* get_version();
+
+} // namespace lambda_runtime
+} // namespace aws

src/runtime.cpp

@@ -14,6 +14,7 @@
  */
 
 #include "aws/lambda-runtime/runtime.h"
+#include "aws/lambda-runtime/version.h"
 #include "aws/lambda-runtime/outcome.h"
 #include "aws/logging/logging.h"
 #include "aws/http/response.h"
@@ -26,7 +27,7 @@
 #include <array>
 #include <cstdlib> // for strtoul
 
-#define LAMBDA_RUNTIME_API __attribute__((visibility("default")))
+#define AWS_LAMBDA_RUNTIME_API __attribute__((visibility("default")))
 
 namespace aws {
 namespace lambda_runtime {
@@ -105,6 +106,12 @@ static size_t write_header(char* ptr, size_t size, size_t nmemb, void* userdata)
     return size * nmemb;
 }
 
+static std::string const& get_user_agent_header()
+{
+    static std::string user_agent = std::string("User-Agent: AWS_Lambda_Cpp/") + get_version();
+    return user_agent;
+}
+
 static size_t read_data(char* buffer, size_t size, size_t nitems, void* userdata)
 {
     auto const limit = size * nitems;
@@ -243,9 +250,13 @@ runtime::next_outcome runtime::get_next()
     curl_easy_setopt(m_curl_handle, CURLOPT_WRITEDATA, &resp);
     curl_easy_setopt(m_curl_handle, CURLOPT_HEADERDATA, &resp);
 
+    curl_slist* headers = nullptr;
+    headers = curl_slist_append(headers, get_user_agent_header().c_str());
+
     logging::log_debug(LOG_TAG, "Making request to %s", m_endpoints[Endpoints::NEXT].c_str());
     CURLcode curl_code = curl_easy_perform(m_curl_handle);
     logging::log_debug(LOG_TAG, "Completed request to %s", m_endpoints[Endpoints::NEXT].c_str());
+    curl_slist_free_all(headers);
 
     if (curl_code != CURLE_OK) {
         logging::log_debug(LOG_TAG, "CURL returned error code %d - %s", curl_code, curl_easy_strerror(curl_code));
@@ -343,6 +354,7 @@ runtime::post_outcome runtime::do_post(
 
     headers = curl_slist_append(headers, "Expect:");
     headers = curl_slist_append(headers, "transfer-encoding:");
+    headers = curl_slist_append(headers, get_user_agent_header().c_str());
     auto const& payload = handler_response.get_payload();
     logging::log_debug(
         LOG_TAG, "calculating content length... %s", ("content-length: " + std::to_string(payload.length())).c_str());
@@ -398,7 +410,7 @@ static bool handle_post_outcome(runtime::post_outcome const& o, std::string cons
     return false;
 }
 
-LAMBDA_RUNTIME_API
+AWS_LAMBDA_RUNTIME_API
 void run_handler(std::function<invocation_response(invocation_request const&)> const& handler)
 {
     logging::log_info(LOG_TAG, "Initializing the C++ Lambda Runtime.");
@@ -501,7 +513,7 @@ static std::string json_escape(std::string const& in)
     return out;
 }
 
-LAMBDA_RUNTIME_API
+AWS_LAMBDA_RUNTIME_API
 invocation_response invocation_response::success(std::string const& payload, std::string const& content_type)
 {
     invocation_response r;
@@ -511,7 +523,7 @@ invocation_response invocation_response::success(std::string const& payload, std
     return r;
 }
 
-LAMBDA_RUNTIME_API
+AWS_LAMBDA_RUNTIME_API
 invocation_response invocation_response::failure(std::string const& error_message, std::string const& error_type)
 {
     invocation_response r;

src/version.cpp.in

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018-present 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.
+ */
+
+#define AWS_LAMBDA_RUNTIME_API __attribute__((visibility("default")))
+
+namespace aws {
+namespace lambda_runtime {
+
+/* clang-format off */
+AWS_LAMBDA_RUNTIME_API
+unsigned get_version_major()
+{
+    return @PROJECT_VERSION_MAJOR@;
+}
+
+AWS_LAMBDA_RUNTIME_API
+unsigned get_version_minor()
+{
+    return @PROJECT_VERSION_MINOR@;
+}
+
+AWS_LAMBDA_RUNTIME_API
+unsigned get_version_patch()
+{
+    return @PROJECT_VERSION_PATCH@;
+}
+/* clang-format on */
+
+AWS_LAMBDA_RUNTIME_API
+char const* get_version()
+{
+    return "@PROJECT_VERSION@";
+}
+
+} // namespace lambda_runtime
+} // namespace aws

tests/CMakeLists.txt

@@ -4,13 +4,12 @@ find_package(GTest REQUIRED)
 
 add_executable(${PROJECT_NAME}
     main.cpp
-    runtime_tests.cpp)
+    runtime_tests.cpp
+    version_tests.cpp)
 
 target_link_libraries(${PROJECT_NAME} PRIVATE ${AWSSDK_LINK_LIBRARIES} aws-lambda-runtime GTest::GTest)
 
-# gtest_discover_tests(${PROJECT_NAME}) Can't use this until CMake 3.10 :(
-# gtest_add_tests(TARGET ${PROJECT_NAME} runtime_tests.cpp)
-GTEST_ADD_TESTS(${PROJECT_NAME} "" AUTO)
+gtest_discover_tests(${PROJECT_NAME}) # requires CMake 3.10 or later
 
 add_subdirectory(resources)
 

tests/version_tests.cpp

@@ -0,0 +1,22 @@
+#include <gtest/gtest.h>
+#include <aws/lambda-runtime/version.h>
+
+using namespace aws::lambda_runtime;
+
+TEST(VersionTests, get_version_major)
+{
+    auto version = get_version_major();
+    ASSERT_EQ(0, version);
+}
+
+TEST(VersionTests, get_version_minor)
+{
+    auto version = get_version_minor();
+    ASSERT_GE(version, 1);
+}
+
+TEST(VersionTests, get_version_patch)
+{
+    auto version = get_version_patch();
+    ASSERT_GE(version, 0);
+}