import opentracing
from opentracing.scope_managers.tornado import TornadoScopeManager
from opentracing_instrumentation import span_in_stack_context, http_server
opentracing.tracer = MyOpenTracingTracer(scope_manager=TornadoScopeManager())
class TracerMiddleware(object):
def __init__(self):
# perform initialization similar to above, including installing
# the client_hooks
@gen.coroutine
def __call__(self, request, handler, next_mw):
request_wrapper = http_server.TornadoRequestWrapper(request=request)
span = http_server.before_request(request=request_wrapper)
@gen.coroutine
def next_middleware_with_span():
yield next_mw()
yield run_coroutine_with_span(span=span,
func=next_middleware_with_span)
span.finish()
def run_coroutine_with_span(span, func, *args, **kwargs):
"""Wrap the execution of a Tornado coroutine func in a tracing span.
This makes the span available through the get_current_span() function.
:param span: The tracing span to expose.
:param func: Co-routine to execute in the scope of tracing span.
:param args: Positional args to func, if any.
:param kwargs: Keyword args to func, if any.
"""
with span_in_stack_context(span):
return func(*args, **kwargs)
