1 files changed, 139 insertions, 0 deletions
diff --git a/grpc/tools/distrib/python/xds_protos/build.py b/grpc/tools/distrib/python/xds_protos/build.py
new file mode 100644
index 00000000..8b793f2b
--- /dev/null
+++ b/grpc/tools/distrib/python/xds_protos/build.py
@@ -0,0 +1,139 @@
+#! /usr/bin/env python3
+# Copyright 2021 The gRPC Authors
+#
+# 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
+#
+#     http://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.
+"""Builds the content of xds-protos package"""
+
+import os
+import pkg_resources
+from grpc_tools import protoc
+
+# We might not want to compile all the protos
+EXCLUDE_PROTO_PACKAGES_LIST = [
+    # Requires extra dependency to Prometheus protos
+    'envoy/service/metrics/v2',
+    'envoy/service/metrics/v3',
+    'envoy/service/metrics/v4alpha',
+]
+
+# Compute the pathes
+WORK_DIR = os.path.dirname(os.path.abspath(__file__))
+GRPC_ROOT = os.path.abspath(os.path.join(WORK_DIR, '..', '..', '..', '..'))
+XDS_PROTO_ROOT = os.path.join(GRPC_ROOT, 'third_party', 'envoy-api')
+UDPA_PROTO_ROOT = os.path.join(GRPC_ROOT, 'third_party', 'udpa')
+GOOGLEAPIS_ROOT = os.path.join(GRPC_ROOT, 'third_party', 'googleapis')
+VALIDATE_ROOT = os.path.join(GRPC_ROOT, 'third_party', 'protoc-gen-validate')
+OPENCENSUS_PROTO_ROOT = os.path.join(GRPC_ROOT, 'third_party',
+                                     'opencensus-proto', 'src')
+WELL_KNOWN_PROTOS_INCLUDE = pkg_resources.resource_filename(
+    'grpc_tools', '_proto')
+OUTPUT_PATH = WORK_DIR
+
+# Prepare the test file generation
+TEST_FILE_NAME = 'generated_file_import_test.py'
+TEST_IMPORTS = []
+
+# The pkgutil-style namespace packaging __init__.py
+PKGUTIL_STYLE_INIT = "__path__ = __import__('pkgutil').extend_path(__path__, __name__)\n"
+NAMESPACE_PACKAGES = ["google"]
+
+
+def add_test_import(proto_package_path: str,
+                    file_name: str,
+                    service: bool = False):
+    TEST_IMPORTS.append("from %s import %s\n" % (proto_package_path.replace(
+        '/', '.'), file_name.replace('.proto', '_pb2')))
+    if service:
+        TEST_IMPORTS.append("from %s import %s\n" % (proto_package_path.replace(
+            '/', '.'), file_name.replace('.proto', '_pb2_grpc')))
+
+
+# Prepare Protoc command
+COMPILE_PROTO_ONLY = [
+    'grpc_tools.protoc',
+    '--proto_path={}'.format(XDS_PROTO_ROOT),
+    '--proto_path={}'.format(UDPA_PROTO_ROOT),
+    '--proto_path={}'.format(GOOGLEAPIS_ROOT),
+    '--proto_path={}'.format(VALIDATE_ROOT),
+    '--proto_path={}'.format(WELL_KNOWN_PROTOS_INCLUDE),
+    '--proto_path={}'.format(OPENCENSUS_PROTO_ROOT),
+    '--python_out={}'.format(OUTPUT_PATH),
+]
+COMPILE_BOTH = COMPILE_PROTO_ONLY + ['--grpc_python_out={}'.format(OUTPUT_PATH)]
+
+
+def has_grpc_service(proto_package_path: str) -> bool:
+    return proto_package_path.startswith('envoy/service')
+
+
+def compile_protos(proto_root: str, sub_dir: str = '.') -> None:
+    for root, _, files in os.walk(os.path.join(proto_root, sub_dir)):
+        proto_package_path = os.path.relpath(root, proto_root)
+        if proto_package_path in EXCLUDE_PROTO_PACKAGES_LIST:
+            print(f'Skipping package {proto_package_path}')
+            continue
+        for file_name in files:
+            if file_name.endswith('.proto'):
+                # Compile proto
+                if has_grpc_service(proto_package_path):
+                    return_code = protoc.main(COMPILE_BOTH +
+                                              [os.path.join(root, file_name)])
+                    add_test_import(proto_package_path, file_name, service=True)
+                else:
+                    return_code = protoc.main(COMPILE_PROTO_ONLY +
+                                              [os.path.join(root, file_name)])
+                    add_test_import(proto_package_path,
+                                    file_name,
+                                    service=False)
+                if return_code != 0:
+                    raise Exception('error: {} failed'.format(COMPILE_BOTH))
+
+
+def create_init_file(path: str, package_path: str = "") -> None:
+    with open(os.path.join(path, "__init__.py"), 'w') as f:
+        # Apply the pkgutil-style namespace packaging, which is compatible for 2
+        # and 3. Here is the full table of namespace compatibility:
+        # https://github.com/pypa/sample-namespace-packages/blob/master/table.md
+        if package_path in NAMESPACE_PACKAGES:
+            f.write(PKGUTIL_STYLE_INIT)
+
+
+def main():
+    # Compile xDS protos
+    compile_protos(XDS_PROTO_ROOT)
+    compile_protos(UDPA_PROTO_ROOT)
+    # We don't want to compile the entire GCP surface API, just the essential ones
+    compile_protos(GOOGLEAPIS_ROOT, os.path.join('google', 'api'))
+    compile_protos(GOOGLEAPIS_ROOT, os.path.join('google', 'rpc'))
+    compile_protos(GOOGLEAPIS_ROOT, os.path.join('google', 'longrunning'))
+    compile_protos(GOOGLEAPIS_ROOT, os.path.join('google', 'logging'))
+    compile_protos(GOOGLEAPIS_ROOT, os.path.join('google', 'type'))
+    compile_protos(VALIDATE_ROOT, 'validate')
+    compile_protos(OPENCENSUS_PROTO_ROOT)
+
+    # Generate __init__.py files for all modules
+    create_init_file(WORK_DIR)
+    for proto_root_module in [
+            'envoy', 'google', 'opencensus', 'udpa', 'validate', 'xds'
+    ]:
+        for root, _, _ in os.walk(os.path.join(WORK_DIR, proto_root_module)):
+            package_path = os.path.relpath(root, WORK_DIR)
+            create_init_file(root, package_path)
+
+    # Generate test file
+    with open(os.path.join(WORK_DIR, TEST_FILE_NAME), 'w') as f:
+        f.writelines(TEST_IMPORTS)
+
+
+if __name__ == "__main__":
+    main()