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feat: add interceptor-like functionality to REST transport #1142

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software-dov merged 5 commits into from
Jan 21, 2022
Merged

feat: add interceptor-like functionality to REST transport #1142

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7102df5
feat: add interceptor-like functionality to REST transport
software-dov Jan 14, 2022
99dbdfb
Initial port to Ads templates
software-dov Jan 19, 2022
a3e49ed
Ads portaging
software-dov Jan 19, 2022
0688986
Disable interceptor generation for streaming methods
software-dov Jan 20, 2022
9e1805f
Integration satiation
software-dov Jan 20, 2022
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2 changes: 2 additions & 0 deletions .../ads-templates/%namespace/%name/%version/%sub/services/%service/transports/__init__.py.j2
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ from .grpc import {{ service.name }}GrpcTransport
{% endif %}
{% if 'rest' in opts.transport %}
from .rest import {{ service.name }}RestTransport
from .rest import {{ service.name }}RestInterceptor
{% endif %}

# Compile a registry of transports.
Expand All @@ -29,6 +30,7 @@ __all__ = (
{% endif %}
{% if 'rest' in opts.transport %}
'{{ service.name }}RestTransport',
'{{ service.name }}RestInterceptor',
{% endif %}
)
{% endblock %}
73 changes: 66 additions & 7 deletions gapic/ads-templates/%namespace/%name/%version/%sub/services/%service/transports/rest.py.j2
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Original file line number Diff line number Diff line change
Expand Up @@ -49,10 +49,67 @@ DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo(
rest_version=requests_version,
)


class {{ service.name }}RestInterceptor:
"""Interceptor for {{ service.name }}.

Interceptors are used to manipulate requests, request metadata, and responses
in arbitrary ways.
Example use cases include:
* Logging
* Verifying requests according to service or custom semantics
* Stripping extraneous information from responses

These use cases and more can be enabled by injecting an
instance of a custom subclass when constructing the {{ service.name }}RestTransport.

.. code-block:
class MyCustom{{ service.name }}Interceptor({{ service.name }}RestInterceptor):
{% for _, method in service.methods|dictsort if not (method.server_streaming or method.client_streaming) %}
def pre_{{ method.name|snake_case }}(request, metadata):
logging.log(f"Received request: {request}")
return request, metadata

{% if not method.void %}
def post_{{ method.name|snake_case }}(response):
logging.log(f"Received response: {response}")
{% endif %}

{% endfor %}
transport = {{ service.name }}RestTransport(interceptor=MyCustom{{ service.name }}Interceptor())
client = {{ service.client_name }}(transport=transport)


"""
{% for method in service.methods.values()|sort(attribute="name") if not(method.server_streaming or method.client_streaming) %}
def pre_{{ method.name|snake_case }}(self, request: {{method.input.ident}}, metadata: Sequence[Tuple[str, str]]) -> Tuple[{{method.input.ident}}, Sequence[Tuple[str, str]]]:
"""Pre-rpc interceptor for {{ method.name|snake_case }}

Override in a subclass to manipulate the request or metadata
before they are sent to the {{ service.name }} server.
"""
return request, metadata

{% if not method.void %}
def post_{{ method.name|snake_case }}(self, response: {{method.output.ident}}) -> {{method.output.ident}}:
"""Post-rpc interceptor for {{ method.name|snake_case }}

Override in a subclass to manipulate the response
after it is returned by the {{ service.name }} server but before
it is returned to user code.
"""
return response
{% endif %}

{% endfor %}


@dataclasses.dataclass
class {{service.name}}RestStub:
_session: AuthorizedSession
_host: str
_interceptor: {{ service.name }}RestInterceptor


class {{service.name}}RestTransport({{service.name}}Transport):
"""REST backend transport for {{ service.name }}.
Expand Down Expand Up @@ -80,6 +137,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
client_info: gapic_v1.client_info.ClientInfo=DEFAULT_CLIENT_INFO,
always_use_jwt_access: Optional[bool]=False,
url_scheme: str='https',
interceptor: Optional[{{ service.name }}RestInterceptor] = None,
) -> None:
"""Instantiate the transport.

Expand Down Expand Up @@ -130,6 +188,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{% endif %}
if client_cert_source_for_mtls:
self._session.configure_mtls_channel(client_cert_source_for_mtls)
self._interceptor = interceptor or {{ service.name }}RestInterceptor()
self._prep_wrapped_messages(client_info)

{% if service.has_lro %}
Expand Down Expand Up @@ -233,7 +292,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
},
{% endfor %}{# rule in method.http_options #}
]

request, metadata = self._interceptor.pre_{{ method.name|snake_case }}(request, metadata)
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@BenRKarl BenRKarl Jan 20, 2022

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At first I imagined we'd be able to pass a list of interceptors that could be chained together, but understand that requires additional architecture here. We can handle the chaining within the body of the pre_/post_ functions.

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@software-dov software-dov Jan 20, 2022 •
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Exactly, that's easily done by something like this:

class InterceptorChainer:
    def __init__(self, chain):
        assert all(isinstance(i, RestInterceptor) for i in chain)
        # Make our own copy to prevent external modification
        self.chain = list(chain)
        
    def __getattr__(self, name):
        if name.startswith("pre_"):
            def pre(request, metadata):
                for i in self.chain:
                    request, metadata = getattr(i, name)(request, metadata)
                return request, metadata
                
            return pre
                
        elif name.startswith("post_"):
            def post(response):
                for i in self.chain:
                    response = getattr(i, name)(response)
                return response
            
            return post
            
        else:
            raise AttributeError(f"No such attribute: {name}")

request_kwargs = {{method.input.ident}}.to_dict(request)
transcoded_request = path_template.transcode(
http_options, **request_kwargs)
Expand Down Expand Up @@ -288,16 +347,16 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{% if not method.void %}
# Return the response
{% if method.lro %}
return_op = operations_pb2.Operation()
json_format.Parse(response.content, return_op, ignore_unknown_fields=True)
return return_op
resp = operations_pb2.Operation()
json_format.Parse(response.content, resp, ignore_unknown_fields=True)
{% else %}
return {{method.output.ident}}.from_json(
resp = {{method.output.ident}}.from_json(
response.content,
ignore_unknown_fields=True
)

{% endif %}{# method.lro #}
resp = self._interceptor.post_{{ method.name|snake_case }}(resp)
return resp
{% endif %}{# method.void #}
{% else %}{# method.http_options and not (method.server_streaming or method.client_streaming) #}
{% if not method.http_options %}
Expand All @@ -323,7 +382,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{{method.output.ident}}]:
stub = self._STUBS.get("{{method.name | snake_case}}")
if not stub:
stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host)
stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)

return stub

Expand Down
50 changes: 50 additions & 0 deletions gapic/ads-templates/tests/unit/gapic/%name_%version/%sub/test_%service.py.j2
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ from google.api_core import grpc_helpers
from google.api_core import path_template
{% if service.has_lro %}
from google.api_core import future
from google.api_core import operation
from google.api_core import operations_v1
from google.longrunning import operations_pb2
{% if "rest" in opts.transport %}
Expand Down Expand Up @@ -1113,6 +1114,55 @@ def test_{{ method_name }}_rest_unset_required_fields():

{% endif %}{# required_fields #}

{% if not (method.server_streaming or method.client_streaming) %}
@pytest.mark.parametrize("null_interceptor", [True, False])
def test_{{ method_name }}_rest_interceptors(null_interceptor):
transport = transports.{{ service.name }}RestTransport(
credentials=ga_credentials.AnonymousCredentials(),
interceptor=None if null_interceptor else transports.{{ service.name}}RestInterceptor(),
)
client = {{ service.client_name }}(transport=transport)
with mock.patch.object(type(client.transport._session), "request") as req, \
mock.patch.object(path_template, "transcode") as transcode, \
{% if method.lro %}
mock.patch.object(operation.Operation, "_set_result_from_operation"), \
{% endif %}
{% if not method.void %}
mock.patch.object(transports.{{ service.name }}RestInterceptor, "post_{{method.name|snake_case}}") as post, \
{% endif %}
mock.patch.object(transports.{{ service.name }}RestInterceptor, "pre_{{ method.name|snake_case }}") as pre:
pre.assert_not_called()
{% if not method.void %}
post.assert_not_called()
{% endif %}

transcode.return_value = {"method": "post", "uri": "my_uri", "body": None, "query_params": {},}

req.return_value = Response()
req.return_value.status_code = 200
req.return_value.request = PreparedRequest()
{% if not method.void %}
req.return_value._content = {% if method.output.ident.package == method.ident.package %}{{ method.output.ident }}.to_json({{ method.output.ident }}()){% else %}json_format.MessageToJson({{ method.output.ident }}()){% endif %}
{% endif %}

request = {{ method.input.ident }}()
metadata =[
("key", "val"),
("cephalopod", "squid"),
]
pre.return_value = request, metadata
{% if not method.void %}
post.return_value = {{ method.output.ident }}
{% endif %}

client.{{ method_name }}(request, metadata=[("key", "val"), ("cephalopod", "squid"),])

pre.assert_called_once()
{% if not method.void %}
post.assert_called_once()
{% endif %}
{% endif %}{# streaming #}


def test_{{ method_name }}_rest_bad_request(transport: str = 'rest', request_type={{ method.input.ident }}):
client = {{ service.client_name }}(
Expand Down
2 changes: 2 additions & 0 deletions gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/__init__.py.j2
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ from .grpc_asyncio import {{ service.name }}GrpcAsyncIOTransport
{% endif %}
{% if 'rest' in opts.transport %}
from .rest import {{ service.name }}RestTransport
from .rest import {{ service.name }}RestInterceptor
{% endif %}


Expand All @@ -34,6 +35,7 @@ __all__ = (
{% endif %}
{% if 'rest' in opts.transport %}
'{{ service.name }}RestTransport',
'{{ service.name }}RestInterceptor',
{% endif %}
)
{% endblock %}
73 changes: 66 additions & 7 deletions gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -49,10 +49,67 @@ DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo(
rest_version=requests_version,
)


class {{ service.name }}RestInterceptor:
"""Interceptor for {{ service.name }}.

Interceptors are used to manipulate requests, request metadata, and responses
in arbitrary ways.
Example use cases include:
* Logging
* Verifying requests according to service or custom semantics
* Stripping extraneous information from responses

These use cases and more can be enabled by injecting an
instance of a custom subclass when constructing the {{ service.name }}RestTransport.

.. code-block:
class MyCustom{{ service.name }}Interceptor({{ service.name }}RestInterceptor):
{% for _, method in service.methods|dictsort if not (method.server_streaming or method.client_streaming) %}
def pre_{{ method.name|snake_case }}(request, metadata):
logging.log(f"Received request: {request}")
return request, metadata

{% if not method.void %}
def post_{{ method.name|snake_case }}(response):
logging.log(f"Received response: {response}")
{% endif %}

{% endfor %}
transport = {{ service.name }}RestTransport(interceptor=MyCustom{{ service.name }}Interceptor())
client = {{ service.client_name }}(transport=transport)


"""
{% for method in service.methods.values()|sort(attribute="name") if not (method.server_streaming or method.client_streaming) %}
def pre_{{ method.name|snake_case }}(self, request: {{method.input.ident}}, metadata: Sequence[Tuple[str, str]]) -> Tuple[{{method.input.ident}}, Sequence[Tuple[str, str]]]:
"""Pre-rpc interceptor for {{ method.name|snake_case }}

Override in a subclass to manipulate the request or metadata
before they are sent to the {{ service.name }} server.
"""
return request, metadata

{% if not method.void %}
def post_{{ method.name|snake_case }}(self, response: {{method.output.ident}}) -> {{method.output.ident}}:
"""Post-rpc interceptor for {{ method.name|snake_case }}

Override in a subclass to manipulate the response
after it is returned by the {{ service.name }} server but before
it is returned to user code.
"""
return response
{% endif %}

{% endfor %}


@dataclasses.dataclass
class {{service.name}}RestStub:
_session: AuthorizedSession
_host: str
_interceptor: {{ service.name }}RestInterceptor


class {{service.name}}RestTransport({{service.name}}Transport):
"""REST backend transport for {{ service.name }}.
Expand Down Expand Up @@ -80,6 +137,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
client_info: gapic_v1.client_info.ClientInfo=DEFAULT_CLIENT_INFO,
always_use_jwt_access: Optional[bool]=False,
url_scheme: str='https',
interceptor: Optional[{{ service.name }}RestInterceptor] = None,
) -> None:
"""Instantiate the transport.

Expand Down Expand Up @@ -130,6 +188,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{% endif %}
if client_cert_source_for_mtls:
self._session.configure_mtls_channel(client_cert_source_for_mtls)
self._interceptor = interceptor or {{ service.name }}RestInterceptor()
self._prep_wrapped_messages(client_info)

{% if service.has_lro %}
Expand Down Expand Up @@ -233,7 +292,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
},
{% endfor %}{# rule in method.http_options #}
]

request, metadata = self._interceptor.pre_{{ method.name|snake_case }}(request, metadata)
request_kwargs = {{method.input.ident}}.to_dict(request)
transcoded_request = path_template.transcode(
http_options, **request_kwargs)
Expand Down Expand Up @@ -288,16 +347,16 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{% if not method.void %}
# Return the response
{% if method.lro %}
return_op = operations_pb2.Operation()
json_format.Parse(response.content, return_op, ignore_unknown_fields=True)
return return_op
resp = operations_pb2.Operation()
json_format.Parse(response.content, resp, ignore_unknown_fields=True)
{% else %}
return {{method.output.ident}}.from_json(
resp = {{method.output.ident}}.from_json(
response.content,
ignore_unknown_fields=True
)

{% endif %}{# method.lro #}
resp = self._interceptor.post_{{ method.name|snake_case }}(resp)
return resp
{% endif %}{# method.void #}
{% else %}{# method.http_options and not (method.server_streaming or method.client_streaming) #}
{% if not method.http_options %}
Expand All @@ -323,7 +382,7 @@ class {{service.name}}RestTransport({{service.name}}Transport):
{{method.output.ident}}]:
stub = self._STUBS.get("{{method.name | snake_case}}")
if not stub:
stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host)
stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)

return stub

Expand Down
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