feat(oauth2): new library to create oauth2 tokens

BUILD.bazel

@@ -134,6 +134,14 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "oauth2",
+    testonly = True,
+    deps = [
+        "//google/cloud/oauth2:google_cloud_cpp_oauth2",
+    ],
+)
+
 cc_library(
     name = "experimental-opentelemetry",
     deps = [

CMakeLists.txt

@@ -259,6 +259,7 @@ if (GOOGLE_CLOUD_CPP_USE_INSTALLED_COMMON)
     endif ()
     if (GOOGLE_CLOUD_CPP_ENABLE_REST)
         find_package(google_cloud_cpp_rest_internal CONFIG REQUIRED)
+        find_package(google_cloud_cpp_oauth2 CONFIG REQUIRED)
     endif ()
     if (GOOGLE_CLOUD_CPP_ENABLE_REST AND GOOGLE_CLOUD_CPP_ENABLE_GRPC)
         find_package(google_cloud_cpp_rest_protobuf_internal CONFIG REQUIRED)

ci/cloudbuild/builds/check-api.sh

@@ -46,7 +46,7 @@ if [ "${GOOGLE_CLOUD_CPP_CHECK_API:-}" ]; then
 else
   mapfile -t library_list < <(cmake -DCMAKE_MODULE_PATH="${PWD}/cmake" -P cmake/print-ga-libraries.cmake 2>&1)
   # These libraries are not "features", but they are part of the public API
-  library_list+=("common" "grpc_utils")
+  library_list+=("common" "grpc_utils" "oauth2")
 fi
 
 # Uses `abi-dumper` to dump the ABI for the given library, which should
@@ -64,7 +64,7 @@ function check_abi() {
   local shortlib="${library#google_cloud_cpp_}"
   local public_headers="${prefix}/include/google/cloud/${shortlib}"
   # These two are special
-  if [[ "${shortlib}" == "common" || "${shortlib}" == "grpc_utils" ]]; then
+  if [[ "${shortlib}" == "common" || "${shortlib}" == "grpc_utils" || "${shortlib}" == "oauth2" ]]; then
     public_headers="${prefix}/include/google/cloud"
   fi
 

ci/cloudbuild/builds/cmake-install.sh

@@ -137,6 +137,7 @@ expected_dirs+=(
   ./lib64/cmake/google_cloud_cpp_grafeas
   ./lib64/cmake/google_cloud_cpp_grpc_utils
   ./lib64/cmake/google_cloud_cpp_mocks
+  ./lib64/cmake/google_cloud_cpp_oauth2
   ./lib64/cmake/google_cloud_cpp_opentelemetry
   ./lib64/cmake/google_cloud_cpp_pubsub_mocks
   ./lib64/cmake/google_cloud_cpp_rest_internal

google/cloud/BUILD.bazel

@@ -17,6 +17,21 @@ package(default_visibility = ["//visibility:private"])
 licenses(["notice"])  # Apache 2.0
 
 load(":capture_build_info.bzl", "capture_build_info")
+load(":google_cloud_cpp_common_benchmarks.bzl", "google_cloud_cpp_common_benchmarks")
+load(":google_cloud_cpp_common_unit_tests.bzl", "google_cloud_cpp_common_unit_tests")
+load(":google_cloud_cpp_common.bzl", "google_cloud_cpp_common_hdrs", "google_cloud_cpp_common_srcs")
+load(":google_cloud_cpp_grpc_utils_benchmarks.bzl", "google_cloud_cpp_grpc_utils_benchmarks")
+load(":google_cloud_cpp_grpc_utils_integration_tests.bzl", "google_cloud_cpp_grpc_utils_integration_tests")
+load(":google_cloud_cpp_grpc_utils_unit_tests.bzl", "google_cloud_cpp_grpc_utils_unit_tests")
+load(":google_cloud_cpp_grpc_utils.bzl", "google_cloud_cpp_grpc_utils_hdrs", "google_cloud_cpp_grpc_utils_srcs")
+load(":google_cloud_cpp_mocks.bzl", "google_cloud_cpp_mocks_hdrs")
+load(":google_cloud_cpp_rest_internal_benchmarks.bzl", "google_cloud_cpp_rest_internal_benchmarks")
+load(":google_cloud_cpp_rest_internal_emulator_integration_tests.bzl", "google_cloud_cpp_rest_internal_emulator_integration_tests")
+load(":google_cloud_cpp_rest_internal_production_integration_tests.bzl", "google_cloud_cpp_rest_internal_production_integration_tests")
+load(":google_cloud_cpp_rest_internal_unit_tests.bzl", "google_cloud_cpp_rest_internal_unit_tests")
+load(":google_cloud_cpp_rest_internal.bzl", "google_cloud_cpp_rest_internal_hdrs", "google_cloud_cpp_rest_internal_srcs")
+load(":google_cloud_cpp_rest_protobuf_internal_unit_tests.bzl", "google_cloud_cpp_rest_protobuf_internal_unit_tests")
+load(":google_cloud_cpp_rest_protobuf_internal.bzl", "google_cloud_cpp_rest_protobuf_internal_hdrs", "google_cloud_cpp_rest_protobuf_internal_srcs")
 
 capture_build_info(
     name = "generate_build_info",
@@ -42,8 +57,6 @@ config_setting(
     },
 )
 
-load(":google_cloud_cpp_common.bzl", "google_cloud_cpp_common_hdrs", "google_cloud_cpp_common_srcs")
-
 cc_library(
     name = "google_cloud_cpp_common_private",
     srcs = google_cloud_cpp_common_srcs + ["internal/build_info.cc"],
@@ -105,11 +118,6 @@ cc_library(
     deps = [":google_cloud_cpp_common_private"],
 )
 
-load(
-    ":google_cloud_cpp_common_unit_tests.bzl",
-    "google_cloud_cpp_common_unit_tests",
-)
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -125,8 +133,6 @@ load(
     ],
 ) for test in google_cloud_cpp_common_unit_tests]
 
-load(":google_cloud_cpp_common_benchmarks.bzl", "google_cloud_cpp_common_benchmarks")
-
 [cc_test(
     name = benchmark.replace("/", "_").replace(".cc", ""),
     srcs = [benchmark],
@@ -137,8 +143,6 @@ load(":google_cloud_cpp_common_benchmarks.bzl", "google_cloud_cpp_common_benchma
     ],
 ) for benchmark in google_cloud_cpp_common_benchmarks]
 
-load(":google_cloud_cpp_grpc_utils.bzl", "google_cloud_cpp_grpc_utils_hdrs", "google_cloud_cpp_grpc_utils_srcs")
-
 cc_library(
     name = "google_cloud_cpp_grpc_utils_private",
     srcs = google_cloud_cpp_grpc_utils_srcs,
@@ -177,8 +181,6 @@ cc_library(
     deps = [":google_cloud_cpp_grpc_utils_private"],
 )
 
-load(":google_cloud_cpp_grpc_utils_unit_tests.bzl", "google_cloud_cpp_grpc_utils_unit_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -194,8 +196,6 @@ load(":google_cloud_cpp_grpc_utils_unit_tests.bzl", "google_cloud_cpp_grpc_utils
     ],
 ) for test in google_cloud_cpp_grpc_utils_unit_tests]
 
-load(":google_cloud_cpp_grpc_utils_integration_tests.bzl", "google_cloud_cpp_grpc_utils_integration_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -214,8 +214,6 @@ load(":google_cloud_cpp_grpc_utils_integration_tests.bzl", "google_cloud_cpp_grp
     ],
 ) for test in google_cloud_cpp_grpc_utils_integration_tests]
 
-load(":google_cloud_cpp_grpc_utils_benchmarks.bzl", "google_cloud_cpp_grpc_utils_benchmarks")
-
 [cc_binary(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -229,8 +227,6 @@ load(":google_cloud_cpp_grpc_utils_benchmarks.bzl", "google_cloud_cpp_grpc_utils
     ],
 ) for test in google_cloud_cpp_grpc_utils_benchmarks]
 
-load(":google_cloud_cpp_mocks.bzl", "google_cloud_cpp_mocks_hdrs")
-
 cc_library(
     name = "google_cloud_cpp_mocks",
     testonly = True,
@@ -245,8 +241,6 @@ cc_library(
     ],
 )
 
-load(":google_cloud_cpp_rest_internal.bzl", "google_cloud_cpp_rest_internal_hdrs", "google_cloud_cpp_rest_internal_srcs")
-
 cc_library(
     name = "google_cloud_cpp_rest_internal",
     srcs = google_cloud_cpp_rest_internal_srcs,
@@ -271,8 +265,6 @@ cc_library(
     ],
 )
 
-load(":google_cloud_cpp_rest_internal_unit_tests.bzl", "google_cloud_cpp_rest_internal_unit_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -284,8 +276,6 @@ load(":google_cloud_cpp_rest_internal_unit_tests.bzl", "google_cloud_cpp_rest_in
     ],
 ) for test in google_cloud_cpp_rest_internal_unit_tests]
 
-load(":google_cloud_cpp_rest_internal_emulator_integration_tests.bzl", "google_cloud_cpp_rest_internal_emulator_integration_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -299,8 +289,6 @@ load(":google_cloud_cpp_rest_internal_emulator_integration_tests.bzl", "google_c
     ],
 ) for test in google_cloud_cpp_rest_internal_emulator_integration_tests]
 
-load(":google_cloud_cpp_rest_internal_production_integration_tests.bzl", "google_cloud_cpp_rest_internal_production_integration_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],
@@ -314,8 +302,6 @@ load(":google_cloud_cpp_rest_internal_production_integration_tests.bzl", "google
     ],
 ) for test in google_cloud_cpp_rest_internal_production_integration_tests]
 
-load(":google_cloud_cpp_rest_internal_benchmarks.bzl", "google_cloud_cpp_rest_internal_benchmarks")
-
 [cc_binary(
     name = benchmark.replace("/", "_").replace(".cc", ""),
     srcs = [benchmark],
@@ -326,8 +312,6 @@ load(":google_cloud_cpp_rest_internal_benchmarks.bzl", "google_cloud_cpp_rest_in
     ],
 ) for benchmark in google_cloud_cpp_rest_internal_benchmarks]
 
-load(":google_cloud_cpp_rest_protobuf_internal.bzl", "google_cloud_cpp_rest_protobuf_internal_hdrs", "google_cloud_cpp_rest_protobuf_internal_srcs")
-
 cc_library(
     name = "google_cloud_cpp_rest_protobuf_internal",
     srcs = google_cloud_cpp_rest_protobuf_internal_srcs,
@@ -340,8 +324,6 @@ cc_library(
     ],
 )
 
-load(":google_cloud_cpp_rest_protobuf_internal_unit_tests.bzl", "google_cloud_cpp_rest_protobuf_internal_unit_tests")
-
 [cc_test(
     name = test.replace("/", "_").replace(".cc", ""),
     srcs = [test],

google/cloud/CMakeLists.txt

@@ -61,6 +61,7 @@ endif ()
 
 if (GOOGLE_CLOUD_CPP_ENABLE_REST)
     include("${CMAKE_CURRENT_SOURCE_DIR}/google_cloud_cpp_rest_internal.cmake")
+    add_subdirectory(oauth2)
 endif ()
 
 if (GOOGLE_CLOUD_CPP_ENABLE_REST AND GOOGLE_CLOUD_CPP_ENABLE_GRPC)

google/cloud/oauth2/BUILD.bazel

@@ -0,0 +1,42 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License 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(default_visibility = ["//visibility:private"])
+
+licenses(["notice"])  # Apache 2.0
+
+load(":google_cloud_cpp_oauth2_unit_tests.bzl", "google_cloud_cpp_oauth2_unit_tests")
+load(":google_cloud_cpp_oauth2.bzl", "google_cloud_cpp_oauth2_hdrs", "google_cloud_cpp_oauth2_srcs")
+
+cc_library(
+    name = "google_cloud_cpp_oauth2",
+    srcs = google_cloud_cpp_oauth2_srcs,
+    hdrs = google_cloud_cpp_oauth2_hdrs,
+    visibility = ["//:__subpackages__"],
+    deps = [
+        "//:common",
+        "//google/cloud:google_cloud_cpp_rest_internal",
+    ],
+)
+
+[cc_test(
+    name = test.replace("/", "_").replace(".cc", ""),
+    srcs = [test],
+    deps = [
+        ":google_cloud_cpp_oauth2",
+        "//google/cloud/testing_util:google_cloud_cpp_testing_private",
+        "//google/cloud/testing_util:google_cloud_cpp_testing_rest_private",
+        "@com_google_googletest//:gtest_main",
+    ],
+) for test in google_cloud_cpp_oauth2_unit_tests]

google/cloud/oauth2/CMakeLists.txt

@@ -0,0 +1,110 @@
+# ~~~
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License 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.
+# ~~~
+
+include(GoogleCloudCppCommon)
+set(DOXYGEN_PROJECT_NAME "OAuth2 Access Token Generation Library")
+set(DOXYGEN_PROJECT_BRIEF
+    "Create OAuth2 Access Tokens for any GCP authentication mechanism")
+set(DOXYGEN_PROJECT_NUMBER "${PROJECT_VERSION}")
+set(DOXYGEN_EXCLUDE_SYMBOLS "internal")
+
+add_library(google_cloud_cpp_oauth2 # cmake-format: sort
+            access_token_generator.cc access_token_generator.h)
+target_link_libraries(
+    google_cloud_cpp_oauth2 PUBLIC google-cloud-cpp::rest_internal
+                                   google-cloud-cpp::common)
+google_cloud_cpp_add_common_options(google_cloud_cpp_oauth2)
+target_include_directories(
+    google_cloud_cpp_oauth2 PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>
+                                   $<INSTALL_INTERFACE:include>)
+target_compile_options(google_cloud_cpp_oauth2
+                       PUBLIC ${GOOGLE_CLOUD_CPP_EXCEPTIONS_FLAG})
+set_target_properties(
+    google_cloud_cpp_oauth2
+    PROPERTIES EXPORT_NAME "google-cloud-cpp::oauth2"
+               VERSION ${PROJECT_VERSION}
+               SOVERSION ${PROJECT_VERSION_MAJOR})
+add_library(google-cloud-cpp::oauth2 ALIAS google_cloud_cpp_oauth2)
+
+# Export the CMake targets to make it easy to create configuration files.
+install(
+    EXPORT google_cloud_cpp_oauth2-targets
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/google_cloud_cpp_oauth2"
+    COMPONENT google_cloud_cpp_development)
+
+# Install the libraries and headers in the locations determined by
+# GNUInstallDirs
+install(
+    TARGETS google_cloud_cpp_oauth2
+    EXPORT google_cloud_cpp_oauth2-targets
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+            COMPONENT google_cloud_cpp_runtime
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            COMPONENT google_cloud_cpp_runtime
+            NAMELINK_COMPONENT google_cloud_cpp_development
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            COMPONENT google_cloud_cpp_development)
+
+google_cloud_cpp_install_headers(google_cloud_cpp_oauth2 include/google/cloud)
+
+google_cloud_cpp_add_pkgconfig(
+    oauth2 "${DOXYGEN_PROJECT_NAME}" "${DOXYGEN_PROJECT_BRIEF}"
+    "google_cloud_cpp_rest_internal" "google_cloud_cpp_common")
+
+# Create and install the CMake configuration files.
+include(CMakePackageConfigHelpers)
+configure_file("config.cmake.in" "google_cloud_cpp_oauth2-config.cmake" @ONLY)
+write_basic_package_version_file(
+    "google_cloud_cpp_oauth2-config-version.cmake"
+    VERSION ${PROJECT_VERSION}
+    COMPATIBILITY ExactVersion)
+
+install(
+    FILES
+        "${CMAKE_CURRENT_BINARY_DIR}/google_cloud_cpp_oauth2-config.cmake"
+        "${CMAKE_CURRENT_BINARY_DIR}/google_cloud_cpp_oauth2-config-version.cmake"
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/google_cloud_cpp_oauth2"
+    COMPONENT google_cloud_cpp_development)
+
+create_bazel_config(google_cloud_cpp_oauth2 YEAR 2023)
+
+set(google_cloud_cpp_oauth2_unit_tests # cmake-format: sort
+                                       access_token_generator_test.cc)
+
+export_list_to_bazel("google_cloud_cpp_oauth2_unit_tests.bzl"
+                     "google_cloud_cpp_oauth2_unit_tests" YEAR 2023)
+
+if (NOT BUILD_TESTING)
+    return()
+endif ()
+
+foreach (fname IN LISTS google_cloud_cpp_oauth2_unit_tests)
+    google_cloud_cpp_add_executable(target "oauth2" "${fname}")
+    target_link_libraries(
+        ${target}
+        PRIVATE google-cloud-cpp::oauth2
+                google_cloud_cpp_testing
+                google_cloud_cpp_testing_rest
+                google-cloud-cpp::common
+                GTest::gmock_main
+                GTest::gmock
+                GTest::gtest)
+    google_cloud_cpp_add_common_options(${target})
+    if (MSVC)
+        target_compile_options(${target} PRIVATE "/bigobj")
+    endif ()
+    add_test(NAME ${target} COMMAND ${target})
+endforeach ()