Refactor Django/Pyramid configuration (#624)

refactor Pyramid config
decouple exporter logic from Django extension
use tracecontext as the default propagator

Author: reyang

README.rst

@@ -143,8 +143,9 @@ Propagators
 ~~~~~~~~~~~
 
 You can specify the propagator type for serializing and deserializing the
-``SpanContext`` and its headers. There are currently three built in propagators:
-``GoogleCloudFormatPropagator``, ``TextFormatPropagator`` and ``TraceContextPropagator``.
+``SpanContext`` and its headers. The default propagator is
+``TraceContextPropagator``, the rest options are ``BinaryFormatPropagator``,
+``GoogleCloudFormatPropagator`` and ``TextFormatPropagator``.
 
 This example shows how to use the ``GoogleCloudFormatPropagator``:
 
@@ -195,13 +196,15 @@ for a Flask application:
     blacklist_paths = ['_ah/health']
     middleware = FlaskMiddleware(app, blacklist_paths=blacklist_paths)
 
-For Django, you can configure the blacklist in the ``OPENCENSUS_TRACE_PARAMS`` in ``settings.py``:
+For Django, you can configure the blacklist in the ``OPENCENSUS`` in ``settings.py``:
 
 .. code:: python
 
-    OPENCENSUS_TRACE_PARAMS: {
-        ...
-        'BLACKLIST_PATHS': ['_ah/health',],
+    OPENCENSUS: {
+        'TRACE': {
+            ...
+            'BLACKLIST_PATHS': ['_ah/health',],
+        }
     }
 
 

contrib/opencensus-ext-azure/examples/client.py

@@ -16,16 +16,11 @@
 
 from opencensus.ext.azure.trace_exporter import AzureExporter
 from opencensus.trace import config_integration
-from opencensus.trace.propagation.trace_context_http_header_format \
-    import TraceContextPropagator
 from opencensus.trace.tracer import Tracer
 
 if __name__ == '__main__':
     config_integration.trace_integrations(['requests'])
-    tracer = Tracer(
-        propagator=TraceContextPropagator(),
-        exporter=AzureExporter(),
-    )
+    tracer = Tracer(exporter=AzureExporter())
     with tracer.span(name='parent'):
         with tracer.span(name='child'):
             response = requests.get(url='http://localhost:8080/')

contrib/opencensus-ext-django/CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Unreleased
+- Decoupled exporter specific logic from configuration
 
 ## 0.2.0
 Released 2019-04-08

contrib/opencensus-ext-django/README.rst

@@ -35,29 +35,17 @@ And add this line to the ``INSTALLED_APPS`` section:
         'opencensus.ext.django',
     ]
 
-You can configure the sampler, exporter, propagator using the ``OPENCENSUS_TRACE`` setting in
-``settings.py``:
+Additional configuration can be provided, please read
+`Customization <https://github.com/census-instrumentation/opencensus-python#customization>`_
+for a complete reference.
 
 .. code:: python
 
-    OPENCENSUS_TRACE = {
-        'SAMPLER': 'opencensus.trace.samplers.probability.ProbabilitySampler',
-        'REPORTER': 'opencensus.trace.print_exporter.PrintExporter',
-        'PROPAGATOR': 'opencensus.trace.propagation.google_cloud_format.'
-                      'GoogleCloudFormatPropagator',
-    }
-
-You can configure the sampling rate and other parameters using the ``OPENCENSUS_TRACE_PARAMS``
-setting in ``settings.py``:
-
-.. code:: python
-
-    OPENCENSUS_TRACE_PARAMS = {
-        'BLACKLIST_PATHS': ['/_ah/health'],
-        'GCP_EXPORTER_PROJECT': None,
-        'SAMPLING_RATE': 0.5,
-        'SERVICE_NAME': 'my_service',
-        'ZIPKIN_EXPORTER_HOST_NAME': 'localhost',
-        'ZIPKIN_EXPORTER_PORT': 9411,
-        'ZIPKIN_EXPORTER_PROTOCOL': 'http',
+    OPENCENSUS = {
+        'TRACE': {
+            'SAMPLER': 'opencensus.trace.samplers.ProbabilitySampler(rate=1)',
+            'EXPORTER': '''opencensus.ext.ocagent.trace_exporter.TraceExporter(
+                service_name='foobar',
+            )''',
+        }
     }

contrib/opencensus-ext-django/examples/app/settings.py

@@ -64,18 +64,13 @@
     },
 ]
 
-OPENCENSUS_TRACE = {
-    'SAMPLER':
-    'opencensus.trace.samplers.always_on.AlwaysOnSampler',
-    'EXPORTER':
-    'opencensus.ext.stackdriver.trace_exporter.StackdriverExporter',
-    'PROPAGATOR':
-    'opencensus.trace.propagation.google_cloud_format.'
-    'GoogleCloudFormatPropagator',
-}
-
-OPENCENSUS_TRACE_PARAMS = {
-    'SAMPLING_RATE': 0.5,
+OPENCENSUS = {
+    'TRACE': {
+        'SAMPLER': 'opencensus.trace.samplers.ProbabilitySampler(rate=0.5)',
+        'EXPORTER': '''opencensus.ext.ocagent.trace_exporter.TraceExporter(
+            service_name='foobar',
+        )''',
+    }
 }
 
 # Internationalization