Use protobuf as schema for JSON APEX manifest

Validate necessary fields in the manifest using protobuf.

Add class for apex manifest for better usability of the JSON fields.

Test: ./runtests.sh

Bug: 116129963
Change-Id: Icf5091ebc9fb4faca437cada3b93cd98c4b77ba6

1 files changed, 60 insertions, 0 deletions

diff --git a/apexer/apex_manifest.py b/apexer/apex_manifest.py
new file mode 100644
index 0000000..8c7eca4
--- /dev/null
+++ b/apexer/apex_manifest.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# 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.
+
+import json
+import manifest_schema_pb2
+from google.protobuf.json_format import Parse
+from google.protobuf.json_format import ParseError
+
+class ApexManifest:
+	# Default values
+	package_name = ""
+	version_number = 0
+	pre_install_hook = ""
+	def __init__(self, manifest_json):
+		self.package_name = manifest_json["name"]
+		self.version_number = manifest_json["version"]
+		if('pre_install_hook' in manifest_json):
+			self.pre_install_hook = manifest_json["pre_install_hook"]
+
+class ApexManifestError(Exception):
+	def __init__(self, errmessage):
+		# Apex Manifest parse error (extra fields) or if required fields not present
+		self.errmessage = errmessage
+
+def ValidateApexManifest(manifest_raw):
+	try:
+		manifest_json = json.loads(manifest_raw)
+		# TODO: The version of protobuf library present in the Android tree at the time of writing
+		# doesn't support the json_name field name. Proto converts underscore field names to
+		# camelCase. To use protobuf with "pre_install_hook" field name, converting to camelCase
+		# explicitly. b/121546801
+		# Convert field names to camelCase
+		for field, value in manifest_json.items():
+			manifest_json[to_camel_case(field)] = manifest_json.pop(field)
+		manifest_pb = Parse(json.dumps(manifest_json), manifest_schema_pb2.ManifestSchema())
+	except (ParseError, ValueError) as err:
+		raise ApexManifestError(err)
+	# Checking required fields
+	if manifest_pb.name == "":
+		raise ApexManifestError("'name' field is required.")
+	if manifest_pb.version == 0:
+		raise ApexManifestError("'version' field is required.")
+	return ApexManifest(manifest_json)
+
+def to_camel_case(snake_str):
+    components = snake_str.split('_')
+    return components[0] + ''.join(x.title() for x in components[1:])
\ No newline at end of file