Exemplo n.º 1
0
def gateway_request_url(api_id, stage_name, path):
    """Return URL for inbound API gateway for given API ID, stage name, and path"""
    pattern = "%s/restapis/{api_id}/{stage_name}/%s{path}" % (
        config.service_url("apigateway"),
        PATH_USER_REQUEST,
    )
    return pattern.format(api_id=api_id, stage_name=stage_name, path=path)
Exemplo n.º 2
0
def _queue_url(path, req_data, headers):
    queue_url = req_data.get("QueueUrl")
    if queue_url:
        return queue_url
    url = config.service_url("sqs")
    if headers.get("Host"):
        url = "%s://%s" % (get_service_protocol(), headers["Host"])
    queue_url = "%s%s" % (url, path.partition("?")[0])
    return queue_url
Exemplo n.º 3
0
 def invoke(cls, invocation_context: ApiInvocationContext):
     try:
         request_templates = RequestTemplates()
         payload = request_templates.render(invocation_context)
     except Exception as e:
         LOG.warning("Failed to apply template for SNS integration", e)
         raise
     uri = (invocation_context.integration.get("uri")
            or invocation_context.integration.get("integrationUri") or "")
     region_name = uri.split(":")[3]
     headers = aws_stack.mock_aws_request_headers(service="sns",
                                                  region_name=region_name)
     return make_http_request(config.service_url("sns"),
                              method="POST",
                              headers=headers,
                              data=payload)
Exemplo n.º 4
0
def invoke_rest_api_integration_backend(
        invocation_context: ApiInvocationContext):
    # define local aliases from invocation context
    invocation_path = invocation_context.path_with_query_string
    method = invocation_context.method
    data = invocation_context.data
    headers = invocation_context.headers
    api_id = invocation_context.api_id
    stage = invocation_context.stage
    resource_path = invocation_context.resource_path
    integration = invocation_context.integration
    integration_response = integration.get("integrationResponses", {})
    response_templates = integration_response.get("200", {}).get(
        "responseTemplates", {})
    # extract integration type and path parameters
    relative_path, query_string_params = extract_query_string_params(
        path=invocation_path)
    integration_type_orig = integration.get("type") or integration.get(
        "integrationType") or ""
    integration_type = integration_type_orig.upper()
    uri = integration.get("uri") or integration.get("integrationUri") or ""
    # XXX we need replace the internal Authorization header with an Authorization header set from
    # the customer, even if it's empty that's what's expected in the integration.
    custom_auth_header = invocation_context.headers.pop(
        HEADER_LOCALSTACK_AUTHORIZATION, "")
    invocation_context.headers["Authorization"] = custom_auth_header

    try:
        path_params = extract_path_params(path=relative_path,
                                          extracted_path=resource_path)
        invocation_context.path_params = path_params
    except Exception:
        path_params = {}

    if (uri.startswith("arn:aws:apigateway:")
            and ":lambda:path" in uri) or uri.startswith("arn:aws:lambda"):
        if integration_type == "AWS_PROXY":
            return LambdaProxyIntegration().invoke(invocation_context)
        elif integration_type == "AWS":
            func_arn = uri
            if ":lambda:path" in uri:
                func_arn = (uri.split(":lambda:path")[1].split("functions/")
                            [1].split("/invocations")[0])

            headers = helpers.create_invocation_headers(invocation_context)
            invocation_context.context = helpers.get_event_request_context(
                invocation_context)
            invocation_context.stage_variables = helpers.get_stage_variables(
                invocation_context)
            if invocation_context.authorizer_type:
                invocation_context.context[
                    "authorizer"] = invocation_context.auth_context

            request_templates = RequestTemplates()
            payload = request_templates.render(invocation_context)

            # TODO: change this signature to InvocationContext as well!
            result = lambda_api.process_apigateway_invocation(
                func_arn,
                relative_path,
                payload,
                stage,
                api_id,
                headers,
                is_base64_encoded=invocation_context.is_data_base64_encoded,
                path_params=path_params,
                query_string_params=query_string_params,
                method=method,
                resource_path=resource_path,
                request_context=invocation_context.context,
                stage_variables=invocation_context.stage_variables,
            )

            if isinstance(result, FlaskResponse):
                response = flask_to_requests_response(result)
            elif isinstance(result, Response):
                response = result
            else:
                response = LambdaResponse()
                parsed_result = (result if isinstance(result, dict) else
                                 json.loads(str(result or "{}")))
                parsed_result = common.json_safe(parsed_result)
                parsed_result = {} if parsed_result is None else parsed_result
                response.status_code = 200
                response._content = parsed_result
                update_content_length(response)

            # apply custom response template
            invocation_context.response = response

            response_templates = ResponseTemplates()
            response_templates.render(invocation_context)
            invocation_context.response.headers["Content-Length"] = str(
                len(response.content or ""))
            return invocation_context.response

        raise Exception(
            f'API Gateway integration type "{integration_type}", action "{uri}", method "{method}"'
        )

    elif integration_type == "AWS":
        if "kinesis:action/" in uri:
            if uri.endswith("kinesis:action/PutRecord"):
                target = kinesis_listener.ACTION_PUT_RECORD
            elif uri.endswith("kinesis:action/PutRecords"):
                target = kinesis_listener.ACTION_PUT_RECORDS
            elif uri.endswith("kinesis:action/ListStreams"):
                target = kinesis_listener.ACTION_LIST_STREAMS
            else:
                LOG.info(
                    f"Unexpected API Gateway integration URI '{uri}' for integration type {integration_type}",
                )
                target = ""

            try:
                invocation_context.context = helpers.get_event_request_context(
                    invocation_context)
                invocation_context.stage_variables = helpers.get_stage_variables(
                    invocation_context)
                request_templates = RequestTemplates()
                payload = request_templates.render(invocation_context)

            except Exception as e:
                LOG.warning("Unable to convert API Gateway payload to str", e)
                raise

            # forward records to target kinesis stream
            headers = aws_stack.mock_aws_request_headers(
                service="kinesis", region_name=invocation_context.region_name)
            headers["X-Amz-Target"] = target

            result = common.make_http_request(
                url=config.service_url("kineses"),
                data=payload,
                headers=headers,
                method="POST")

            # apply response template
            invocation_context.response = result
            response_templates = ResponseTemplates()
            response_templates.render(invocation_context)
            return invocation_context.response

        elif "states:action/" in uri:
            action = uri.split("/")[-1]

            if APPLICATION_JSON in integration.get("requestTemplates", {}):
                request_templates = RequestTemplates()
                payload = request_templates.render(invocation_context)
                payload = json.loads(payload)
            else:
                # XXX decoding in py3 sounds wrong, this actually might break
                payload = json.loads(data.decode("utf-8"))
            client = aws_stack.connect_to_service("stepfunctions")

            if isinstance(payload.get("input"), dict):
                payload["input"] = json.dumps(payload["input"])

            # Hot fix since step functions local package responses: Unsupported Operation: 'StartSyncExecution'
            method_name = (camel_to_snake_case(action)
                           if action != "StartSyncExecution" else
                           "start_execution")

            try:
                method = getattr(client, method_name)
            except AttributeError:
                msg = "Invalid step function action: %s" % method_name
                LOG.error(msg)
                return make_error_response(msg, 400)

            result = method(**payload)
            result = json_safe(
                {k: result[k]
                 for k in result if k not in "ResponseMetadata"})
            response = requests_response(
                content=result,
                headers=aws_stack.mock_aws_request_headers(),
            )

            if action == "StartSyncExecution":
                # poll for the execution result and return it
                result = await_sfn_execution_result(result["executionArn"])
                result_status = result.get("status")
                if result_status != "SUCCEEDED":
                    return make_error_response(
                        "StepFunctions execution %s failed with status '%s'" %
                        (result["executionArn"], result_status),
                        500,
                    )
                result = json_safe(result)
                response = requests_response(content=result)

            # apply response templates
            invocation_context.response = response
            response_templates = ResponseTemplates()
            response_templates.render(invocation_context)
            # response = apply_request_response_templates(
            #     response, response_templates, content_type=APPLICATION_JSON
            # )
            return response
        # https://docs.aws.amazon.com/apigateway/api-reference/resource/integration/
        elif ("s3:path/" in uri or "s3:action/" in uri) and method == "GET":
            s3 = aws_stack.connect_to_service("s3")
            uri = apply_request_parameters(
                uri,
                integration=integration,
                path_params=path_params,
                query_params=query_string_params,
            )
            uri_match = re.match(TARGET_REGEX_PATH_S3_URI, uri) or re.match(
                TARGET_REGEX_ACTION_S3_URI, uri)
            if uri_match:
                bucket, object_key = uri_match.group("bucket", "object")
                LOG.debug("Getting request for bucket %s object %s", bucket,
                          object_key)
                try:
                    object = s3.get_object(Bucket=bucket, Key=object_key)
                except s3.exceptions.NoSuchKey:
                    msg = "Object %s not found" % object_key
                    LOG.debug(msg)
                    return make_error_response(msg, 404)

                headers = aws_stack.mock_aws_request_headers(service="s3")

                if object.get("ContentType"):
                    headers["Content-Type"] = object["ContentType"]

                # stream used so large files do not fill memory
                response = request_response_stream(stream=object["Body"],
                                                   headers=headers)
                return response
            else:
                msg = "Request URI does not match s3 specifications"
                LOG.warning(msg)
                return make_error_response(msg, 400)

        if method == "POST":
            if uri.startswith("arn:aws:apigateway:") and ":sqs:path" in uri:
                template = integration["requestTemplates"][APPLICATION_JSON]
                account_id, queue = uri.split("/")[-2:]
                region_name = uri.split(":")[3]
                if "GetQueueUrl" in template or "CreateQueue" in template:
                    request_templates = RequestTemplates()
                    payload = request_templates.render(invocation_context)
                    new_request = f"{payload}&QueueName={queue}"
                else:
                    request_templates = RequestTemplates()
                    payload = request_templates.render(invocation_context)
                    queue_url = f"{config.get_edge_url()}/{account_id}/{queue}"
                    new_request = f"{payload}&QueueUrl={queue_url}"
                headers = aws_stack.mock_aws_request_headers(
                    service="sqs", region_name=region_name)

                url = urljoin(config.service_url("sqs"),
                              f"{TEST_AWS_ACCOUNT_ID}/{queue}")
                result = common.make_http_request(url,
                                                  method="POST",
                                                  headers=headers,
                                                  data=new_request)
                return result
            elif uri.startswith("arn:aws:apigateway:") and ":sns:path" in uri:
                invocation_context.context = helpers.get_event_request_context(
                    invocation_context)
                invocation_context.stage_variables = helpers.get_stage_variables(
                    invocation_context)

                integration_response = SnsIntegration().invoke(
                    invocation_context)
                return apply_request_response_templates(
                    integration_response,
                    response_templates,
                    content_type=APPLICATION_JSON)

        raise Exception(
            'API Gateway AWS integration action URI "%s", method "%s" not yet implemented'
            % (uri, method))

    elif integration_type == "AWS_PROXY":
        if uri.startswith("arn:aws:apigateway:") and ":dynamodb:action" in uri:
            # arn:aws:apigateway:us-east-1:dynamodb:action/PutItem&Table=MusicCollection
            table_name = uri.split(":dynamodb:action")[1].split("&Table=")[1]
            action = uri.split(":dynamodb:action")[1].split("&Table=")[0]

            if "PutItem" in action and method == "PUT":
                response_template = response_templates.get("application/json")

                if response_template is None:
                    msg = "Invalid response template defined in integration response."
                    LOG.info("%s Existing: %s", msg, response_templates)
                    return make_error_response(msg, 404)

                response_template = json.loads(response_template)
                if response_template["TableName"] != table_name:
                    msg = "Invalid table name specified in integration response template."
                    return make_error_response(msg, 404)

                dynamo_client = aws_stack.connect_to_resource("dynamodb")
                table = dynamo_client.Table(table_name)

                event_data = {}
                data_dict = json.loads(data)
                for key, _ in response_template["Item"].items():
                    event_data[key] = data_dict[key]

                table.put_item(Item=event_data)
                response = requests_response(event_data)
                return response
        else:
            raise Exception(
                'API Gateway action uri "%s", integration type %s not yet implemented'
                % (uri, integration_type))

    elif integration_type in ["HTTP_PROXY", "HTTP"]:

        if ":servicediscovery:" in uri:
            # check if this is a servicediscovery integration URI
            client = aws_stack.connect_to_service("servicediscovery")
            service_id = uri.split("/")[-1]
            instances = client.list_instances(
                ServiceId=service_id)["Instances"]
            instance = (instances or [None])[0]
            if instance and instance.get("Id"):
                uri = "http://%s/%s" % (instance["Id"],
                                        invocation_path.lstrip("/"))

        # apply custom request template
        invocation_context.context = helpers.get_event_request_context(
            invocation_context)
        invocation_context.stage_variables = helpers.get_stage_variables(
            invocation_context)
        request_templates = RequestTemplates()
        payload = request_templates.render(invocation_context)

        if isinstance(payload, dict):
            payload = json.dumps(payload)

        uri = apply_request_parameters(
            uri,
            integration=integration,
            path_params=path_params,
            query_params=query_string_params,
        )
        result = requests.request(method=method,
                                  url=uri,
                                  data=payload,
                                  headers=headers)
        # apply custom response template
        invocation_context.response = result
        response_templates = ResponseTemplates()
        response_templates.render(invocation_context)
        return invocation_context.response

    elif integration_type == "MOCK":
        mock_integration = MockIntegration()
        return mock_integration.invoke(invocation_context)

    if method == "OPTIONS":
        # fall back to returning CORS headers if this is an OPTIONS request
        return get_cors_response(headers)

    raise Exception(
        'API Gateway integration type "%s", method "%s", URI "%s" not yet implemented'
        % (integration_type, method, uri))
Exemplo n.º 5
0
 def _gateway_request_url(self, api_id, stage_name, path):
     pattern = "%s/restapis/{api_id}/{stage_name}/%s{path}" % (
         config.service_url("apigateway"),
         PATH_USER_REQUEST,
     )
     return pattern.format(api_id=api_id, stage_name=stage_name, path=path)
Exemplo n.º 6
0
def invoke_rest_api_integration_backend(
        invocation_context: ApiInvocationContext):
    # define local aliases from invocation context
    invocation_path = invocation_context.path_with_query_string
    method = invocation_context.method
    path = invocation_context.path
    data = invocation_context.data
    headers = invocation_context.headers
    api_id = invocation_context.api_id
    stage = invocation_context.stage
    resource_path = invocation_context.resource_path
    response_templates = invocation_context.response_templates
    integration = invocation_context.integration

    # extract integration type and path parameters
    relative_path, query_string_params = extract_query_string_params(
        path=invocation_path)
    integration_type_orig = integration.get("type") or integration.get(
        "integrationType") or ""
    integration_type = integration_type_orig.upper()
    uri = integration.get("uri") or integration.get("integrationUri") or ""
    try:
        path_params = extract_path_params(path=relative_path,
                                          extracted_path=resource_path)
    except Exception:
        path_params = {}

    if (uri.startswith("arn:aws:apigateway:")
            and ":lambda:path" in uri) or uri.startswith("arn:aws:lambda"):
        if integration_type in ["AWS", "AWS_PROXY"]:
            func_arn = uri
            if ":lambda:path" in uri:
                func_arn = (uri.split(":lambda:path")[1].split("functions/")
                            [1].split("/invocations")[0])

            # apply custom request template
            data_str = data
            is_base64_encoded = False
            try:
                data_str = json.dumps(data) if isinstance(
                    data, (dict, list)) else to_str(data)
                data_str = apply_template(
                    integration,
                    "request",
                    data_str,
                    path_params=path_params,
                    query_params=query_string_params,
                    headers=headers,
                )
            except UnicodeDecodeError:
                data_str = base64.b64encode(data_str)
                is_base64_encoded = True
            except Exception as e:
                LOG.warning("Unable to convert API Gateway payload to str: %s",
                            (e))
                pass

            # Sample request context:
            # https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html#api-gateway-create-api-as-simple-proxy-for-lambda-test
            request_context = get_event_request_context(invocation_context)
            stage_variables = (get_stage_variables(api_id, stage)
                               if not is_test_invoke_method(method, path) else
                               None)
            # TODO: change this signature to InvocationContext as well!
            result = lambda_api.process_apigateway_invocation(
                func_arn,
                relative_path,
                data_str,
                stage,
                api_id,
                headers,
                is_base64_encoded=is_base64_encoded,
                path_params=path_params,
                query_string_params=query_string_params,
                method=method,
                resource_path=resource_path,
                request_context=request_context,
                event_context=invocation_context.context,
                stage_variables=stage_variables,
            )

            if isinstance(result, FlaskResponse):
                response = flask_to_requests_response(result)
            elif isinstance(result, Response):
                response = result
            else:
                response = LambdaResponse()
                parsed_result = (result if isinstance(result, dict) else
                                 json.loads(str(result or "{}")))
                parsed_result = common.json_safe(parsed_result)
                parsed_result = {} if parsed_result is None else parsed_result
                response.status_code = int(parsed_result.get(
                    "statusCode", 200))
                parsed_headers = parsed_result.get("headers", {})
                if parsed_headers is not None:
                    response.headers.update(parsed_headers)
                try:
                    result_body = parsed_result.get("body")
                    if isinstance(result_body, dict):
                        response._content = json.dumps(result_body)
                    else:
                        body_bytes = to_bytes(to_str(result_body or ""))
                        if parsed_result.get("isBase64Encoded", False):
                            body_bytes = base64.b64decode(body_bytes)
                        response._content = body_bytes
                except Exception as e:
                    LOG.warning("Couldn't set Lambda response content: %s", e)
                    response._content = "{}"
                update_content_length(response)
                response.multi_value_headers = parsed_result.get(
                    "multiValueHeaders") or {}

            # apply custom response template
            response._content = apply_template(integration, "response",
                                               response._content)
            response.headers["Content-Length"] = str(
                len(response.content or ""))

            return response

        raise Exception(
            'API Gateway integration type "%s", action "%s", method "%s" invalid or not yet implemented'
            % (integration_type, uri, method))

    elif integration_type == "AWS":
        if "kinesis:action/" in uri:
            if uri.endswith("kinesis:action/PutRecord"):
                target = kinesis_listener.ACTION_PUT_RECORD
            elif uri.endswith("kinesis:action/PutRecords"):
                target = kinesis_listener.ACTION_PUT_RECORDS
            elif uri.endswith("kinesis:action/ListStreams"):
                target = kinesis_listener.ACTION_LIST_STREAMS
            else:
                LOG.info(
                    f"Unexpected API Gateway integration URI '{uri}' for integration type {integration_type}",
                )
                target = ""

            try:
                data = json.dumps(data) if isinstance(data,
                                                      (dict,
                                                       list)) else to_str(data)
                payload = apply_template(
                    integration,
                    "request",
                    data,
                    path_params=path_params,
                    query_params=query_string_params,
                    headers=headers,
                )
            except Exception as e:
                LOG.warning("Unable to convert API Gateway payload to str", e)
                raise

            # forward records to target kinesis stream
            headers = aws_stack.mock_aws_request_headers(
                service="kinesis", region_name=invocation_context.region_name)
            headers["X-Amz-Target"] = target

            result = common.make_http_request(
                url=config.service_url("kineses"),
                data=payload,
                headers=headers,
                method="POST")

            # apply response template
            result = apply_request_response_templates(
                result, response_templates, content_type=APPLICATION_JSON)
            return result

        elif "states:action/" in uri:
            action = uri.split("/")[-1]

            if APPLICATION_JSON in integration.get("requestTemplates", {}):
                payload = apply_request_response_templates(
                    data,
                    integration.get("requestTemplates"),
                    content_type=APPLICATION_JSON,
                    as_json=True,
                )
            else:
                payload = json.loads(data.decode("utf-8"))
            client = aws_stack.connect_to_service("stepfunctions")

            if isinstance(payload.get("input"), dict):
                payload["input"] = json.dumps(payload["input"])

            # Hot fix since step functions local package responses: Unsupported Operation: 'StartSyncExecution'
            method_name = (camel_to_snake_case(action)
                           if action != "StartSyncExecution" else
                           "start_execution")

            try:
                method = getattr(client, method_name)
            except AttributeError:
                msg = "Invalid step function action: %s" % method_name
                LOG.error(msg)
                return make_error_response(msg, 400)

            result = method(**payload)
            result = json_safe(
                {k: result[k]
                 for k in result if k not in "ResponseMetadata"})
            response = requests_response(
                content=result,
                headers=aws_stack.mock_aws_request_headers(),
            )

            if action == "StartSyncExecution":
                # poll for the execution result and return it
                result = await_sfn_execution_result(result["executionArn"])
                result_status = result.get("status")
                if result_status != "SUCCEEDED":
                    return make_error_response(
                        "StepFunctions execution %s failed with status '%s'" %
                        (result["executionArn"], result_status),
                        500,
                    )
                result = json_safe(result)
                response = requests_response(content=result)

            # apply response templates
            response = apply_request_response_templates(
                response, response_templates, content_type=APPLICATION_JSON)
            return response

        elif "s3:path/" in uri and method == "GET":
            s3 = aws_stack.connect_to_service("s3")
            uri_match = re.match(TARGET_REGEX_S3_URI, uri)
            if uri_match:
                bucket, object_key = uri_match.group("bucket", "object")
                LOG.debug("Getting request for bucket %s object %s", bucket,
                          object_key)
                try:
                    object = s3.get_object(Bucket=bucket, Key=object_key)
                except s3.exceptions.NoSuchKey:
                    msg = "Object %s not found" % object_key
                    LOG.debug(msg)
                    return make_error_response(msg, 404)

                headers = aws_stack.mock_aws_request_headers(service="s3")

                if object.get("ContentType"):
                    headers["Content-Type"] = object["ContentType"]

                # stream used so large files do not fill memory
                response = request_response_stream(stream=object["Body"],
                                                   headers=headers)
                return response
            else:
                msg = "Request URI does not match s3 specifications"
                LOG.warning(msg)
                return make_error_response(msg, 400)

        if method == "POST":
            if uri.startswith("arn:aws:apigateway:") and ":sqs:path" in uri:
                template = integration["requestTemplates"][APPLICATION_JSON]
                account_id, queue = uri.split("/")[-2:]
                region_name = uri.split(":")[3]
                if "GetQueueUrl" in template or "CreateQueue" in template:
                    new_request = (
                        f"{aws_stack.render_velocity_template(template, data)}&QueueName={queue}"
                    )
                else:
                    queue_url = f"{config.get_edge_url()}/{account_id}/{queue}"
                    new_request = (
                        f"{aws_stack.render_velocity_template(template, data)}&QueueUrl={queue_url}"
                    )
                headers = aws_stack.mock_aws_request_headers(
                    service="sqs", region_name=region_name)

                url = urljoin(config.service_url("sqs"),
                              f"{TEST_AWS_ACCOUNT_ID}/{queue}")
                result = common.make_http_request(url,
                                                  method="POST",
                                                  headers=headers,
                                                  data=new_request)
                return result

        raise Exception(
            'API Gateway AWS integration action URI "%s", method "%s" not yet implemented'
            % (uri, method))

    elif integration_type == "AWS_PROXY":
        if uri.startswith("arn:aws:apigateway:") and ":dynamodb:action" in uri:
            # arn:aws:apigateway:us-east-1:dynamodb:action/PutItem&Table=MusicCollection
            table_name = uri.split(":dynamodb:action")[1].split("&Table=")[1]
            action = uri.split(":dynamodb:action")[1].split("&Table=")[0]

            if "PutItem" in action and method == "PUT":
                response_template = response_templates.get("application/json")

                if response_template is None:
                    msg = "Invalid response template defined in integration response."
                    LOG.info("%s Existing: %s", msg, response_templates)
                    return make_error_response(msg, 404)

                response_template = json.loads(response_template)
                if response_template["TableName"] != table_name:
                    msg = "Invalid table name specified in integration response template."
                    return make_error_response(msg, 404)

                dynamo_client = aws_stack.connect_to_resource("dynamodb")
                table = dynamo_client.Table(table_name)

                event_data = {}
                data_dict = json.loads(data)
                for key, _ in response_template["Item"].items():
                    event_data[key] = data_dict[key]

                table.put_item(Item=event_data)
                response = requests_response(event_data)
                return response
        else:
            raise Exception(
                'API Gateway action uri "%s", integration type %s not yet implemented'
                % (uri, integration_type))

    elif integration_type in ["HTTP_PROXY", "HTTP"]:

        if ":servicediscovery:" in uri:
            # check if this is a servicediscovery integration URI
            client = aws_stack.connect_to_service("servicediscovery")
            service_id = uri.split("/")[-1]
            instances = client.list_instances(
                ServiceId=service_id)["Instances"]
            instance = (instances or [None])[0]
            if instance and instance.get("Id"):
                uri = "http://%s/%s" % (instance["Id"],
                                        invocation_path.lstrip("/"))

        # apply custom request template
        data = apply_template(integration, "request", data)
        if isinstance(data, dict):
            data = json.dumps(data)
        uri = apply_request_parameters(uri,
                                       integration=integration,
                                       path_params=path_params,
                                       query_params=query_string_params)
        result = requests.request(method=method,
                                  url=uri,
                                  data=data,
                                  headers=headers)
        # apply custom response template
        result = apply_template(integration, "response", result)
        return result

    elif integration_type == "MOCK":
        # return empty response - details filled in via responseParameters above...
        return requests_response({})

    if method == "OPTIONS":
        # fall back to returning CORS headers if this is an OPTIONS request
        return get_cors_response(headers)

    raise Exception(
        'API Gateway integration type "%s", method "%s", URI "%s" not yet implemented'
        % (integration_type, method, uri))