haystack-client 0.2.0

Haystack Python OpenTracing Implementation

Haystack bindings for Python OpenTracing API

This is Haystack's client library for Python that implements OpenTracing

Further information can be found on opentracing.io

Using this library

See examples in /examples directory. See opentracing usage for additional information.

It is important to consider the architecture of the application. In order for the tracer to manage spans properly, an appropriate ScopeManager implementation must be chosen. In most environments, the default ThreadLocalScopeManager will work just fine. In asynchronous frameworks, the ContextVarsScopeManager is a better choice.

First initialize the tracer at the application level by supplying a service name and span recorder

import opentracing
from haystack import HaystackAgentRecorder
from haystack import HaystackTracer

tracer = HaystackTracer("a_service", HaystackAgentRecorder())
opentracing.set_global_tracer(tracer)

Starting a span can be done as a managed resource using start_active_span()

with opentracing.tracer.start_active_span("span-name") as scope:
    do_stuff()

or finish the span on your own terms with

span = opentracing.tracer.start_span("span-name")
do_stuff()
span.finish()

Note: If there is a Scope, it will act as the parent to any newly started Span unless the programmer passes ignore_active_span=True at start_span()/start_active_span() time or specified parent context explicitly using childOf=parent_context

Custom propagation headers

If necessary, default propagation headers can be replaced with custom ones by specifying custom propagator options. Register the new propagator with the tracer once configured.

prop_opts = PropagatorOpts("X-Trace-ID", "X-Span-ID", "X-Parent-Span", "X-baggage-")
opentracing.tracer.register_propagator(opentracing.Format.HTTP_HEADERS, TextPropagator(prop_opts))

Logging

All modules define their logger via logging.getLogger(__name__)

So in order to define specific logging format or level for this library use getLogger('haystack') or configure the root logger.

How to configure build environment

Create a python3 virtual environment, activate it and then make bootstrap

Running the example code

make example

How to Release this library

Create a new release in github specifying a semver compliant tag greater than the current release version.