Opentelemetry 1.4.0上下文传播

Question

我运行的是Opentelemetry 0.18rc1，我的应用程序运行得很好。

我使用W3C跟踪上下文规范进行上下文传播。对于注入和提取，我使用了TraceContextTextMapPropagator

from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator
from opentelemetry.context import get_current

prop = TraceContextTextMapPropagator()
carrier = {}
prop.inject(set_in_carrier=dict.__setitem__, carrier=carrier, context=get_current())

对于下一个微服务中的提取，我使用：

from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator
from opentelemetry.propagators import textmap

prop = TraceContextTextMapPropagator()
carrier_getter = textmap.DictGetter()
context = prop.extract(carrier_getter, request.headers)

当我试图升级到最新的opentelemetry 1.4.0版本时，我的注入和提取方法停止工作。新版本中似乎删除了DictGetter()类，所以我不知道如何在extract方法中设置getter参数。此外，在inject方法中，set_in_carrier被替换为setter参数，我也不确定如何设置这个参数。

如何实现opentelemetry 1.4.0 for W3C Trace Context规范中的Inject和Extract方法？

Answer 1

set_in_carrier被称为Setter的东西取代，DefaultSetter实现了在类似字典的载体中设置值(例如，HTTP报头)。您不需要显式地传递当前上下文，因为如果不传递任何上下文，它将获取当前上下文。并且注入到载体中将被简化为

from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator

prop = TraceContextTextMapPropagator()
carrier = {}
prop.inject(carrier=carrier)

当你提取它的时候

from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator

prop = TraceContextTextMapPropagator()
context = prop.extract(carrier=request.headers)

这是一个工作示例，当注入和提取发生在同一个文件中时，但在现实世界中，它通常发生在不同的服务中。

from opentelemetry import trace
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import (BatchSpanProcessor,
                                            ConsoleSpanExporter)
from opentelemetry.trace.propagation.tracecontext import \
    TraceContextTextMapPropagator

trace.set_tracer_provider(TracerProvider())
trace.get_tracer_provider().add_span_processor(BatchSpanProcessor(ConsoleSpanExporter()))

tracer = trace.get_tracer(__name__)

prop = TraceContextTextMapPropagator()
carrier = {}

# Injecting

with tracer.start_as_current_span("first-span") as span:
    prop.inject(carrier=carrier)
    print("Carrier after injecting span context", carrier)

# Extracting

ctx = prop.extract(carrier=carrier)
with tracer.start_as_current_span("next-span", context=ctx):
    pass