def test_debug_id():
debug_header = 'correlation-id'
tracer = Tracer(
service_name='test',
reporter=InMemoryReporter(),
sampler=ConstSampler(True),
debug_id_header=debug_header,
)
tracer.codecs[Format.TEXT_MAP] = TextCodec(
url_encoding=False,
debug_id_header=debug_header,
)
carrier = {debug_header: 'Coraline'}
context = tracer.extract(Format.TEXT_MAP, carrier)
assert context.is_debug_id_container_only
assert context.debug_id == 'Coraline'
span = tracer.start_span('test', child_of=context)
assert span.is_debug()
assert span.is_sampled()
tags = [t for t in span.tags if t.key == debug_header]
assert len(tags) == 1
assert tags[0].vStr == 'Coraline'
def test_debug_id():
debug_header = 'correlation-id'
tracer = Tracer(
service_name='test',
reporter=InMemoryReporter(),
sampler=ConstSampler(True),
debug_id_header=debug_header,
)
tracer.codecs[Format.TEXT_MAP] = TextCodec(
url_encoding=False,
debug_id_header=debug_header,
)
carrier = {debug_header: 'Coraline'}
context = tracer.extract(Format.TEXT_MAP, carrier)
assert context.is_debug_id_container_only
assert context.debug_id == 'Coraline'
span = tracer.start_span('test', child_of=context)
assert span.is_debug()
assert span.is_sampled()
tags = [t for t in span.tags if t.key == debug_header]
assert len(tags) == 1
assert tags[0].vStr == 'Coraline'
class SimpleTracer:
'''A very basic OpenTracing tracer, with null reporter'''
def __init__(self, sname):
self.tracer = Tracer(one_span_per_rpc=True,
service_name=sname,
reporter=NullReporter(),
sampler=ConstSampler(decision=True),
extra_codecs={Format.HTTP_HEADERS: B3Codec()})
def trace(self):
'''
Decorator that creates opentracing span from incoming b3 headers
'''
def decorator(f):
def wrapper(*args, **kwargs):
global stack
request = stack.top.request
try:
# Create a new span context, reading in values (traceid,
# spanid, etc) from the incoming x-b3-*** headers.
span_ctx = self.tracer.extract(Format.HTTP_HEADERS,
dict(request.headers))
# Note: this tag means that the span will *not* be
# a child span. It will use the incoming traceid and
# spanid. We do this to propagate the headers verbatim.
rpc_tag = {tags.SPAN_KIND: tags.SPAN_KIND_RPC_SERVER}
span = self.tracer.start_span(operation_name='op',
child_of=span_ctx,
tags=rpc_tag)
except Exception as e:
# We failed to create a context, possibly due to no
# incoming x-b3-*** headers. Start a fresh span.
# Note: This is a fallback only, and will create fresh
# headers, not propagate headers.
span = self.tracer.start_span('op')
with span_in_context(span):
r = f(*args, **kwargs)
return r
wrapper.__name__ = f.__name__
return wrapper
return decorator
def getForwardHeaders(self, request):
'''
Return the headers that should be forwarded to subservices.
This function currently forwards instances of tracing headers
for a much wider range of tracing tools than are used in
this course. If those headers are not present, nothing
happens other than a bit of wasted computation here.
At some point, we should pare down the list to only those
headers needed by the tools used in class.
The final block, "Application-specific", includes headers
not needed for tracing but that our application requires to
be forwarded.
'''
headers = {}
# x-b3-*** headers can be populated using the opentracing span
span = get_current_span()
carrier = {}
self.tracer.inject(span_context=span.context,
format=Format.HTTP_HEADERS,
carrier=carrier)
headers.update(carrier)
# CMPT 756 --- COMMENTED OUT FROM bookinfo
# We handle other (non x-b3-***) headers manually
#if 'user' in session:
# headers['end-user'] = session['user']
# Keep this in sync with the headers in details and reviews.
incoming_headers = [
# All applications should propagate x-request-id. This header is
# included in access log statements and is used for consistent trace
# sampling and log sampling decisions in Istio.
'x-request-id',
# Lightstep tracing header. Propagate this if you use lightstep tracing
# in Istio (see
# https://istio.io/latest/docs/tasks/observability/distributed-tracing/lightstep/)
# Note: this should probably be changed to use B3 or W3C TRACE_CONTEXT.
# Lightstep recommends using B3 or TRACE_CONTEXT and most application
# libraries from lightstep do not support x-ot-span-context.
'x-ot-span-context',
# Datadog tracing header. Propagate these headers if you use Datadog
# tracing.
'x-datadog-trace-id',
'x-datadog-parent-id',
'x-datadog-sampling-priority',
# W3C Trace Context. Compatible with OpenCensusAgent and Stackdriver Istio
# configurations.
'traceparent',
'tracestate',
# Cloud trace context. Compatible with OpenCensusAgent and Stackdriver Istio
# configurations.
'x-cloud-trace-context',
# Grpc binary trace context. Compatible with OpenCensusAgent nad
# Stackdriver Istio configurations.
'grpc-trace-bin',
# b3 trace headers. Compatible with Zipkin, OpenCensusAgent, and
# Stackdriver Istio configurations. Commented out since they are
# propagated by the OpenTracing tracer above.
# 'x-b3-traceid',
# 'x-b3-spanid',
# 'x-b3-parentspanid',
# 'x-b3-sampled',
# 'x-b3-flags',
# Application-specific headers to forward.
'user-agent',
'Authorization', # CMPT 756
]
# For Zipkin, always propagate b3 headers.
# For Lightstep, always propagate the x-ot-span-context header.
# For Datadog, propagate the corresponding datadog headers.
# For OpenCensusAgent and Stackdriver configurations, you can choose any
# set of compatible headers to propagate within your application. For
# example, you can propagate b3 headers or W3C trace context headers with
# the same result. This can also allow you to translate between context
# propagation mechanisms between different applications.
for ihdr in incoming_headers:
val = request.headers.get(ihdr)
if val is not None:
headers[ihdr] = val
return headers
