This commit is the initial attempt in converting a protobuf schema
into a yang schema. Intructions on how to execute this convertion is
in the proto2yang.py header. Test cases to follow.
Change-Id: I7a9273138339bbaf521a2b5eab3e5f1205f79bd0
diff --git a/experiments/proto2Yang/addressbook.proto b/experiments/proto2Yang/addressbook.proto
new file mode 100644
index 0000000..bfdceea
--- /dev/null
+++ b/experiments/proto2Yang/addressbook.proto
@@ -0,0 +1,33 @@
+// See README.txt for information and build instructions.
+
+syntax = "proto3";
+
+package tutorial;
+
+option java_package = "com.example.tutorial";
+option java_outer_classname = "AddressBookProtos";
+option csharp_namespace = "Google.Protobuf.Examples.AddressBook";
+
+message Person {
+ string name = 1;
+ int32 id = 2; // Unique ID number for this person.
+ string email = 3;
+
+ enum PhoneType {
+ MOBILE = 0;
+ HOME = 1;
+ WORK = 2;
+ }
+
+ message PhoneNumber {
+ string number = 1;
+ PhoneType type = 2;
+ }
+
+ repeated PhoneNumber phones = 4;
+}
+
+// Our address book file is just one of these.
+message AddressBook {
+ repeated Person people = 1;
+}
diff --git a/experiments/proto2Yang/descriptor.desc b/experiments/proto2Yang/descriptor.desc
new file mode 100644
index 0000000..ac12c36
--- /dev/null
+++ b/experiments/proto2Yang/descriptor.desc
Binary files differ
diff --git a/experiments/proto2Yang/descriptor_parser.py b/experiments/proto2Yang/descriptor_parser.py
new file mode 100644
index 0000000..c23f497
--- /dev/null
+++ b/experiments/proto2Yang/descriptor_parser.py
@@ -0,0 +1,164 @@
+#
+# Copyright 2016 the original author or 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.
+#
+import os
+from collections import OrderedDict
+
+from google.protobuf import descriptor_pb2
+from google.protobuf.descriptor import FieldDescriptor, Descriptor
+from google.protobuf.message import Message
+
+
+class InvalidDescriptorError(Exception): pass
+
+
+class DescriptorParser(object):
+ """
+ Used to parse protobuf FileDescriptor objects into native Python
+ data structures (nested dict/list/intrinsic values. Two of the typical
+ sources of FileDescriptor objects are:
+ 1. CodeGeneratorRequest, used as binary input to any protoc plugin,
+ contains a list of these FileDescriptor objects (under the
+ proto_file attribute)
+ 2. FileDescriptorSet, as saved by protoc when using the -o option.
+
+ An important feature of the parser is that it can process the source
+ code annotations and can fold comments into the relevant defintions
+ present in the proto file.
+
+ Usage (in a protoc plugin):
+ >>> request = plugin.CodeGeneratorRequest()
+ >>> request.ParseFromString(sys.stdin.read())
+ >>> parser = DescriptorParser()
+ >>> for proto_file in request.proto_file:
+ >>> parsed_data = parser.parse_file_descriptor()
+ >>> print json.dumps(parsed_data, indent=4)
+ """
+
+ meta = None
+
+ def __init__(self):
+ if DescriptorParser.meta is None:
+ DescriptorParser.meta = self.load_meta_descriptor()
+
+ def load_meta_descriptor(self):
+ """
+ Load the protobuf version of descriptor.proto to use it in
+ decoding protobuf paths.
+ """
+ fpath = os.path.abspath(os.path.join(os.path.dirname(__file__),
+ 'descriptor.desc'))
+ with open(fpath, 'r') as f:
+ blob = f.read()
+ proto = descriptor_pb2.FileDescriptorSet()
+ proto.ParseFromString(blob)
+ assert len(proto.file) == 1
+ return proto.file[0]
+
+ parser_table = {
+ unicode: lambda x: x,
+ int: lambda x: x,
+ bool: lambda x: x,
+ }
+
+ def parse(self, o, type_tag_name=None):
+ if isinstance(o, Message):
+ return self.parse_message(o, type_tag_name)
+ else:
+ return self.parser_table[type(o)](o)
+
+ def parse_message(self, m, type_tag_name=None):
+ assert isinstance(m, Message)
+ d = OrderedDict()
+ for field, value in m.ListFields():
+ assert isinstance(field, FieldDescriptor)
+ if field.label in (1, 2):
+ d[field.name] = self.parse(value, type_tag_name)
+ elif field.label == 3:
+ d[field.name] = [self.parse(x, type_tag_name) for x in
+ value]
+ else:
+ raise InvalidDescriptorError()
+
+ if type_tag_name is not None:
+ d[type_tag_name] = m.DESCRIPTOR.full_name.strip('.')
+
+ return d
+
+ def parse_file_descriptor(self, descriptor,
+ type_tag_name=None,
+ fold_comments=False):
+
+ d = self.parse(descriptor, type_tag_name=type_tag_name)
+
+ if fold_comments:
+ locations = d.get('source_code_info', {}).get('location', [])
+ for location in locations:
+ path = location.get('path', [])
+ comments = ''.join([
+ location.get('leading_comments', '').strip(' '),
+ location.get('trailing_comments', '').strip(' '),
+ ''.join(block.strip(' ') for block
+ in
+ location.get('leading_detached_comments', ''))
+ ]).strip()
+
+ # ignore locations with no comments
+ if not comments:
+ continue
+
+ # we ignore path with odd number of entries, since these do
+ # not address our schema nodes, but rather the meta schema
+ if (len(path) % 2 == 0):
+ node = self.find_node_by_path(
+ path, self.meta.DESCRIPTOR, d)
+ assert isinstance(node, dict)
+ node['_description'] = comments
+
+ # remove source_code_info
+ del d['source_code_info']
+
+ return d
+
+ def parse_file_descriptors(self, descriptors,
+ type_tag_name=None,
+ fold_comments=False):
+ return [self.parse_file_descriptor(descriptor,
+ type_tag_name=type_tag_name,
+ fold_comments=fold_comments)
+ for descriptor in descriptors]
+
+ def find_node_by_path(self, path, meta, o):
+ # stop recursion when path is empty
+ if not path:
+ return o
+
+ # sanity check
+ assert len(path) >= 2
+ assert isinstance(meta, Descriptor)
+ assert isinstance(o, dict)
+
+ # find field name, then actual field
+ field_number = path.pop(0)
+ field_def = meta.fields_by_number[field_number]
+ field = o[field_def.name]
+
+ # field must be a list, extract entry with given index
+ assert isinstance(field, list) # expected to be a list field
+ index = path.pop(0)
+ child_o = field[index]
+
+ child_meta = field_def.message_type
+ return self.find_node_by_path(path, child_meta, child_o)
diff --git a/experiments/proto2Yang/proto2yang.py b/experiments/proto2Yang/proto2yang.py
new file mode 100755
index 0000000..9b039fd
--- /dev/null
+++ b/experiments/proto2Yang/proto2yang.py
@@ -0,0 +1,376 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 the original author or 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.
+#
+
+"""protoc plugin to convert a protobuf schema to a yang schema
+
+ - basic support for message, fields. enumeration, service, method
+
+ - yang semantic rules needs to be implemented
+
+ - to run this plugin :
+
+ $ python -m grpc.tools.protoc -I.
+ --plugin=protoc-gen-custom=./proto2yang.py --custom_out=. <proto file>.proto
+
+ - the above will produce a <proto file>.yang file formatted for yang
+
+ - two examples of proto that can be used in the same directory are
+ yang.proto and addressbook.proto
+
+"""
+
+import sys
+
+from jinja2 import Template
+from google.protobuf.compiler import plugin_pb2 as plugin
+from descriptor_parser import DescriptorParser
+
+from google.protobuf.descriptor import FieldDescriptor
+
+template_yang = Template("""
+module {{ module.name }} {
+
+ namespace "https://gerrit.opencord.org/voltha/{{ module.package }}";
+ yang-version 1.1;
+
+ prefix "voltha";
+
+ revision 2016-11-15 {{ module.revision }} {
+ {% if module.description %}
+ /* {{ message.description }} */
+ {% else %}
+ description "Initial revision.";
+ {% endif %}
+ }
+ {% for message in module.messages recursive %}
+ grouping {{ message.name }} {
+ {% if message.description %}
+ /* {{ message.description }} */
+ {% endif %}
+ {% if message.key %}
+ key {{ message.key_name }} ;
+ {% endif %}
+ {% for field in message.fields %}
+ {% if field.type_ref %}
+ {% if field.description %}
+ /* {{ field.description }} */
+ {% endif %}
+ uses {{ field.type }} ;
+ {% else %}
+ leaf {{ field.name }} {
+ {% if field.type == "decimal64" %}
+ type {{ field.type }} {
+ fraction-digits 5;
+ }
+ {% else %}
+ type {{ field.type }} ;
+ {% endif %}
+ {% if field.description %}
+ description
+ "{{ field.description }}" ;
+ {% endif %}
+ }
+ {% endif %}
+ {% endfor %}
+ {% for enum_type in message.enums %}
+ {% if enum_type.description %}
+ /* {{ enum_type.description }} */ ;
+ {% endif %}
+ typedef {{ enum_type.name }} {
+ type enumeration {
+ {% for v in enum_type.value %}
+ {% if v.description %}
+ enum {{ v.name }} {
+ description "{{ v.description }}";
+ }
+ {% else %}
+ enum {{ v.name }} ;
+ {% endif %}
+ {% endfor %}
+ }
+ }
+ {% endfor %}
+ {% for oneof in message.oneof %}
+ choice {{ oneof.name }} {
+ }
+ {% endfor %}
+ {% if message.messages %}
+ {{ loop (message.messages)|indent(4, false) }}
+ {% endif %}
+ }
+ {% endfor %}
+
+ {% for service in module.services %}
+ {% if service.description %}
+ /* {{ service.description }}" */
+ {% endif %}
+
+ {% for method in service.methods %}
+ {% if method.description %}
+ /* {{ method.description }} */
+ {% endif %}
+ rpc {{ service.service }}-{{ method.method }} {
+ {% if method.input %}
+ input {
+ {% if method.input_ref %}
+ uses {{ method.input }} ;
+ {% else %}
+ leaf {{ method.input }} {
+ type {{ method.input }} ;
+ }
+ {% endif %}
+ }
+ {% endif %}
+ {% if method.output %}
+ output {
+ {% if method.output_ref %}
+ uses {{ method.output }} ;
+ {% else %}
+ leaf {{ method.output }} {
+ type {{ method.output }} ;
+ }
+ {% endif %}
+ }
+ {% endif %}
+ }
+ {% endfor %}
+ {% endfor %}
+}
+""", trim_blocks=True, lstrip_blocks=True)
+
+
+def _traverse_messages(message_types):
+ messages = []
+ for message_type in message_types:
+ assert message_type['_type'] == 'google.protobuf.DescriptorProto'
+ # parse the fields
+ fields = _traverse_fields(message_type.get('field', []))
+
+ # parse the enums
+ enums = _traverse_enums(message_type.get('enum_type', []))
+
+ # parse nested messages
+ nested = message_type.get('nested_type', [])
+ nested_messages = _traverse_messages(nested)
+ messages.append(
+ {
+ 'name': message_type.get('name', ''),
+ 'fields': fields,
+ 'enums': enums,
+ # 'extensions': extensions,
+ 'messages': nested_messages,
+ 'description': message_type.get('_description', ''),
+ # 'extension_ranges': extension_ranges,
+ # 'oneof': oneof
+ }
+ )
+ return messages
+
+
+def _traverse_fields(fields_desc):
+ fields = []
+ for field in fields_desc:
+ assert field['_type'] == 'google.protobuf.FieldDescriptorProto'
+ fields.append(
+ {
+ 'name': field.get('name', ''),
+ 'label': field.get('label', ''),
+ 'number': field.get('number', ''),
+ 'options': field.get('options', ''),
+ 'type_name': field.get('type_name', ''),
+ 'type': get_yang_type(field),
+ 'type_ref': not is_base_type(field['type']),
+ 'description': remove_unsupported_characters(field.get(
+ '_description', ''))
+ }
+ )
+ return fields
+
+
+def _traverse_enums(enums_desc):
+ enums = []
+ for enum in enums_desc:
+ assert enum['_type'] == 'google.protobuf.EnumDescriptorProto'
+ enums.append(
+ {
+ 'name': enum.get('name', ''),
+ 'value': enum.get('value', ''),
+ 'description': enum.get('_description', '')
+ }
+ )
+ return enums
+
+
+def _traverse_services(service_desc):
+ services = []
+ for service in service_desc:
+ methods = []
+ for method in service.get('method', []):
+ assert method['_type'] == 'google.protobuf.MethodDescriptorProto'
+ input_name = method.get('input_type')
+ input_ref = False
+ if not is_base_type(input_name):
+ input_name = input_name.split('.')[-1]
+ input_ref = True
+ output_name = method.get('output_type')
+ output_ref = False
+ if not is_base_type(output_name):
+ output_name = output_name.split('.')[-1]
+ output_ref = True
+ methods.append(
+ {
+ 'method': method.get('name', ''),
+ 'input': input_name,
+ 'input_ref': input_ref,
+ 'output': output_name,
+ 'output_ref': output_ref,
+ 'description': method.get('_description', ''),
+ 'server_streaming': method.get('server_streaming',
+ False) == True
+ }
+ )
+ services.append(
+ {
+ 'service': service.get('name', ''),
+ 'methods': methods,
+ 'description': service.get('_description', ''),
+ }
+ )
+ return services
+
+
+def _rchop(thestring, ending):
+ if thestring.endswith(ending):
+ return thestring[:-len(ending)]
+ return thestring
+
+
+def _traverse_desc(descriptor):
+ name = _rchop(descriptor.get('name', ''), '.proto')
+ package = descriptor.get('package', '')
+ description = descriptor.get('_description', '')
+ messages = _traverse_messages(descriptor.get('message_type', []))
+ enums = _traverse_enums(descriptor.get('enum_type', []))
+ services = _traverse_services(descriptor.get('service', []))
+ # extensions = _traverse_extensions(descriptors)
+ # options = _traverse_options(descriptors)
+
+ data = {
+ 'name': name,
+ 'package': package,
+ 'description' : description,
+ 'messages': messages,
+ 'enums': enums,
+ 'services': services,
+ # 'extensions': extensions,
+ # 'options': options
+ }
+
+ return data
+
+
+def generate_code(request, response):
+ assert isinstance(request, plugin.CodeGeneratorRequest)
+
+ parser = DescriptorParser()
+
+ # idx = 1
+ for proto_file in request.proto_file:
+ native_data = parser.parse_file_descriptor(proto_file,
+ type_tag_name='_type',
+ fold_comments=True)
+
+ # print native_data
+ yang_data = _traverse_desc(native_data)
+
+ f = response.file.add()
+ #TODO: We should have a separate file for each output. There is an
+ # issue reusing the same filename with an incremental suffix. Using
+ # a different file name works but not the actual proto file name
+ f.name = proto_file.name.replace('.proto', '.yang')
+ # f.name = '{}_{}{}'.format(_rchop(proto_file.name, '.proto'), idx,
+ # '.yang')
+ # idx += 1
+ f.content = template_yang.render(module=yang_data)
+
+def get_yang_type(field):
+ type = field['type']
+ if type in YANG_TYPE_MAP.keys():
+ _type, _ = YANG_TYPE_MAP[type]
+ if _type in ['enumeration', 'message', 'group']:
+ return field['type_name'].split('.')[-1]
+ else:
+ return _type
+ else:
+ return type
+
+def is_base_type(type):
+ # check numeric value of the type first
+ if type in YANG_TYPE_MAP.keys():
+ _type, _ = YANG_TYPE_MAP[type]
+ return _type not in ['message', 'group']
+ else:
+ # proto name of the type
+ result = [ _format for ( _ , _format) in YANG_TYPE_MAP.values() if
+ _format == type and _format not in ['message', 'group']]
+ return len(result) > 0
+
+def remove_unsupported_characters(text):
+ unsupported_characters = ["{", "}", "[", "]", "\"", "/", "\\"]
+ return ''.join([i if i not in unsupported_characters else ' ' for i in text])
+
+YANG_TYPE_MAP = {
+ FieldDescriptor.TYPE_BOOL: ('boolean', 'boolean'),
+ FieldDescriptor.TYPE_BYTES: ('binary', 'byte'),
+ FieldDescriptor.TYPE_DOUBLE: ('decimal64', 'double'),
+ FieldDescriptor.TYPE_ENUM: ('enumeration', 'enum'),
+ FieldDescriptor.TYPE_FIXED32: ('int32', 'int64'),
+ FieldDescriptor.TYPE_FIXED64: ('int64', 'uint64'),
+ FieldDescriptor.TYPE_FLOAT: ('decimal64', 'float'),
+ FieldDescriptor.TYPE_INT32: ('int32', 'int32'),
+ FieldDescriptor.TYPE_INT64: ('int64', 'int64'),
+ FieldDescriptor.TYPE_SFIXED32: ('int32', 'int32'),
+ FieldDescriptor.TYPE_SFIXED64: ('int64', 'int64'),
+ FieldDescriptor.TYPE_STRING: ('string', 'string'),
+ FieldDescriptor.TYPE_SINT32: ('int32', 'int32'),
+ FieldDescriptor.TYPE_SINT64: ('int64', 'int64'),
+ FieldDescriptor.TYPE_UINT32: ('uint32', 'int64'),
+ FieldDescriptor.TYPE_UINT64: ('uint64', 'uint64'),
+ FieldDescriptor.TYPE_MESSAGE: ('message', 'message'),
+ FieldDescriptor.TYPE_GROUP: ('group', 'group')
+}
+
+if __name__ == '__main__':
+ # Read request message from stdin
+ data = sys.stdin.read()
+
+ # Parse request
+ request = plugin.CodeGeneratorRequest()
+ request.ParseFromString(data)
+
+ # Create response
+ response = plugin.CodeGeneratorResponse()
+
+ # Generate code
+ generate_code(request, response)
+
+ # Serialise response message
+ output = response.SerializeToString()
+
+ # Write to stdout
+ sys.stdout.write(output)
+ # print is_base_type(9)
\ No newline at end of file
diff --git a/experiments/proto2Yang/yang.proto b/experiments/proto2Yang/yang.proto
new file mode 100644
index 0000000..94959a3
--- /dev/null
+++ b/experiments/proto2Yang/yang.proto
@@ -0,0 +1,67 @@
+syntax = "proto3";
+
+package experiment;
+
+//import "google/protobuf/empty.proto";
+
+message AsyncEvent {
+ int32 seq = 1;
+ enum EventType {
+ BIG_BANG = 0; // just a big bang
+ SMALL_BANG = 1; // so small bang
+ NO_BANG = 2;
+ }
+ EventType type = 2;
+ string details = 3;
+}
+
+enum khenType {
+ BIG_KHEN = 0;
+ SMALL_KHEN = 1;
+ NO_KHEN = 2;
+}
+
+
+message Packet {
+ int32 source = 1;
+ bytes content = 2;
+ message Result {
+ string url = 1;
+ string title = 2;
+ repeated string snippets = 3;
+ message Success {
+ string input = 1;
+ string desc = 2;
+ }
+ repeated Success success = 4;
+ }
+ repeated Result results = 3;
+}
+
+message Echo {
+ string msg = 1;
+ float delay = 2;
+}
+
+message testMessage{
+ oneof oneOfTest {
+ string test2 = 1;
+ int32 test3 = 2;
+ }
+}
+
+service ExperimentalService {
+
+ rpc GetEcho(Echo) returns(Echo);
+
+ // For server to send async stream to client
+ rpc ReceiveStreamedEvents(Packet)
+ returns(stream AsyncEvent);
+
+ // For server to send async packets to client
+ rpc ReceivePackets(Echo) returns(stream Packet);
+
+ // For client to send async packets to server
+ rpc SendPackets(stream Packet) returns(Echo);
+
+}
\ No newline at end of file