Flask-OpenTracing 2.0.0

Initialize

FlaskTracing wraps the tracer instance that’s supported by opentracing. To create a FlaskTracing object, you can either pass in a tracer object directly or a callable that returns the tracer object. For example:

import opentracing
from flask_opentracing import FlaskTracing

opentracing_tracer = ## some OpenTracing tracer implementation
tracing = FlaskTracing(opentracing_tracer, ...)

or

import opentracing
from flask_opentracing import FlaskTracing

def initialize_tracer():
    ...
    return opentracing_tracer

tracing = FlaskTracing(initialize_tracer, ...)

Trace All Requests

import opentracing
from flask_opentracing import FlaskTracing

app = Flask(__name__)

opentracing_tracer = ## some OpenTracing tracer implementation
tracing = FlaskTracing(opentracing_tracer, True, app, [optional_args])

Trace Individual Requests

import opentracing
from flask_opentracing import FlaskTracing

app = Flask(__name__)

opentracing_tracer = ## some OpenTracing tracer implementation
tracing = FlaskTracing(opentracing_tracer)

@app.route('/some_url')
@tracing.trace(optional_args)
def some_view_func():
    ...
    return some_view

Accessing Spans Manually

In order to access the span for a request, we’ve provided an method FlaskTracing.get_span(request) that returns the span for the request, if it is exists and is not finished. This can be used to log important events to the span, set tags, or create child spans to trace non-RPC events. If no request is passed in, the current request will be used.

Tracing an RPC

If you want to make an RPC and continue an existing trace, you can inject the current span into the RPC. For example, if making an http request, the following code will continue your trace across the wire:

@tracing.trace()
def some_view_func(request):
    new_request = some_http_request
    current_span = tracing.get_span(request)
    text_carrier = {}
    opentracing_tracer.inject(span, opentracing.Format.TEXT_MAP, text_carrier)
    for k, v in text_carrier.iteritems():
        new_request.add_header(k,v)
    ... # make request