elasticapm/instrumentation/packages/starlette.py

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import weakref
from typing import TYPE_CHECKING

from elasticapm.instrumentation.packages.base import AbstractInstrumentedModule

if TYPE_CHECKING:
    from starlette.applications import Starlette


class StarletteInstrumentation(AbstractInstrumentedModule):
    name = "starlette"

    instrument_list = [("starlette.applications", "Starlette.build_middleware_stack")]

    instrumented_apps = []

    creates_transactions = True

    def call(self, module, method, wrapped, instance: "Starlette", args, kwargs):
        from elasticapm.contrib.starlette import ElasticAPM

        if ElasticAPM not in instance.user_middleware:
            instance.add_middleware(ElasticAPM, client=None)
            self.instrumented_apps.append(weakref.ref(instance))
        return wrapped(*args, **kwargs)