Merge pull request #14 from appoptics/NH-12018-distro-and-configurator-setup

NH-12018 Separate Distro vs Configurator

Author: tammy-baylis-swi

Diff for: opentelemetry_distro_solarwinds/configurator.py

@@ -0,0 +1,86 @@
+"""Module to initialize OpenTelemetry SDK components to work with SolarWinds backend"""
+
+import logging
+from os import environ
+from pkg_resources import (
+    iter_entry_points,
+    load_entry_point
+)
+
+from opentelemetry import trace
+from opentelemetry.environment_variables import (
+    OTEL_PROPAGATORS,
+    OTEL_TRACES_EXPORTER
+)
+from opentelemetry.instrumentation.propagators import set_global_response_propagator
+from opentelemetry.propagate import set_global_textmap
+from opentelemetry.propagators.composite import CompositePropagator
+from opentelemetry.sdk._configuration import _OTelSDKConfigurator
+from opentelemetry.sdk.environment_variables import OTEL_TRACES_SAMPLER
+from opentelemetry.sdk.trace import TracerProvider
+from opentelemetry.sdk.trace.export import BatchSpanProcessor
+
+from opentelemetry_distro_solarwinds.response_propagator import SolarWindsTraceResponsePropagator
+
+logger = logging.getLogger(__name__)
+
+class SolarWindsConfigurator(_OTelSDKConfigurator):
+    """OpenTelemetry Configurator for initializing SolarWinds-reporting SDK components"""
+
+    # Cannot set as env default because not part of OTel Python _KNOWN_SAMPLERS
+    # https://github.com/open-telemetry/opentelemetry-python/blob/main/opentelemetry-sdk/src/opentelemetry/sdk/trace/sampling.py#L364-L380
+    _DEFAULT_SW_TRACES_SAMPLER = "solarwinds_sampler"
+
+    def _configure(self, **kwargs):
+        environ_sampler = environ.get(
+            OTEL_TRACES_SAMPLER,
+            self._DEFAULT_SW_TRACES_SAMPLER,
+        )
+        try:
+            sampler = load_entry_point(
+                "opentelemetry_distro_solarwinds",
+                "opentelemetry_traces_sampler",
+                environ_sampler
+            )()
+        except:
+            logger.exception(
+                "Failed to load configured sampler `%s`", environ_sampler
+            )
+            raise
+        trace.set_tracer_provider(
+            TracerProvider(sampler=sampler))
+
+        environ_exporter = environ.get(OTEL_TRACES_EXPORTER)
+        try:
+            exporter = load_entry_point(
+                "opentelemetry_distro_solarwinds",
+                "opentelemetry_traces_exporter",
+                environ_exporter
+            )()
+        except:
+            logger.exception(
+                "Failed to load configured exporter `%s`", environ_exporter
+            )
+            raise
+        span_exporter = BatchSpanProcessor(exporter)
+        trace.get_tracer_provider().add_span_processor(span_exporter)
+
+        # Init and set CompositePropagator globally, like OTel API
+        environ_propagators = environ.get(OTEL_PROPAGATORS).split(",")
+        propagators = []
+        for propagator in environ_propagators:
+            try:
+                propagators.append(
+                    next(
+                        iter_entry_points("opentelemetry_propagator", propagator)
+                    ).load()()
+                )
+            except Exception:
+                logger.exception(
+                    "Failed to load configured propagator `%s`", propagator
+                )
+                raise
+        set_global_textmap(CompositePropagator(propagators))
+
+        # Set global HTTP response propagator
+        set_global_response_propagator(SolarWindsTraceResponsePropagator())

Diff for: opentelemetry_distro_solarwinds/distro.py

@@ -1,87 +1,52 @@
-"""Module to configure OpenTelemetry agent to work with SolarWinds backend"""
+"""Module to configure OpenTelemetry to work with SolarWinds backend"""
 
 import logging
 from os import environ
-from pkg_resources import iter_entry_points
 
-from opentelemetry import trace
-from opentelemetry.environment_variables import OTEL_PROPAGATORS, OTEL_TRACES_EXPORTER
+from opentelemetry.environment_variables import (
+    OTEL_PROPAGATORS,
+    OTEL_TRACES_EXPORTER
+)
 from opentelemetry.instrumentation.distro import BaseDistro
-from opentelemetry.instrumentation.propagators import set_global_response_propagator
-from opentelemetry.propagate import set_global_textmap
-from opentelemetry.propagators.composite import CompositePropagator
-from opentelemetry.sdk.trace import TracerProvider
-from opentelemetry.sdk.trace.export import BatchSpanProcessor
-
-from opentelemetry_distro_solarwinds.response_propagator import SolarWindsTraceResponsePropagator
-from opentelemetry_distro_solarwinds.sampler import ParentBasedSwSampler
+from opentelemetry.sdk.environment_variables import OTEL_TRACES_SAMPLER
 
 logger = logging.getLogger(__name__)
 
 class SolarWindsDistro(BaseDistro):
-    """SolarWinds custom distro for OpenTelemetry agents."""
+    """OpenTelemetry Distro for SolarWinds reporting environment"""
 
-    _DEFAULT_OTEL_EXPORTER = "solarwinds_exporter"
-    _DEFAULT_OTEL_PROPAGATORS = [
-        "tracecontext",
+    _TRACECONTEXT_PROPAGATOR = "tracecontext"
+    _SW_PROPAGATOR = "solarwinds_propagator"
+    _DEFAULT_SW_PROPAGATORS = [
+        _TRACECONTEXT_PROPAGATOR,
         "baggage",
-        "solarwinds_propagator",
+        _SW_PROPAGATOR,
     ]
+    _DEFAULT_SW_TRACES_EXPORTER = "solarwinds_exporter"
 
     def _configure(self, **kwargs):
-        # Automatically use custom SolarWinds sampler
-        trace.set_tracer_provider(
-            TracerProvider(sampler=ParentBasedSwSampler()))
-
-        # Customize Exporter else default to SolarWindsSpanExporter
-        environ_exporter = environ.get(
-            OTEL_TRACES_EXPORTER,
-            self._DEFAULT_OTEL_EXPORTER
-        )
-        try:
-            exporter = next(
-                iter_entry_points(
-                    "opentelemetry_traces_exporter",
-                    environ_exporter
-                )).load()()
-        except:
-            logger.exception(
-                "Failed to load configured exporter `%s`", environ_exporter
-            )
-            raise
-
-        span_exporter = BatchSpanProcessor(exporter)
-        trace.get_tracer_provider().add_span_processor(span_exporter)
-
-        # Configure context propagators to always include
-        # tracecontext,baggage,solarwinds -- first and in that order
-        # -- plus any others specified by env var
+        environ.setdefault(OTEL_TRACES_EXPORTER, self._DEFAULT_SW_TRACES_EXPORTER)
+        
         environ_propagators = environ.get(
             OTEL_PROPAGATORS,
-            ",".join(self._DEFAULT_OTEL_PROPAGATORS)
+            ",".join(self._DEFAULT_SW_PROPAGATORS)
         ).split(",")
-        if environ_propagators != self._DEFAULT_OTEL_PROPAGATORS:
-            for default in self._DEFAULT_OTEL_PROPAGATORS:
-                while default in environ_propagators:
-                    environ_propagators.remove(default)
-            environ_propagators = self._DEFAULT_OTEL_PROPAGATORS + environ_propagators
+        # If not using the default propagators,
+        # can any arbitrary list BUT
+        # (1) must include tracecontext and solarwinds_propagator
+        # (2) tracecontext must be before solarwinds_propagator
+        if environ_propagators != self._DEFAULT_SW_PROPAGATORS:
+            if not self._TRACECONTEXT_PROPAGATOR in environ_propagators or \
+                not self._SW_PROPAGATOR in environ_propagators:
+                raise ValueError("Must include tracecontext and solarwinds_propagator in OTEL_PROPAGATORS to use SolarWinds Observability.")
+
+            if environ_propagators.index(self._SW_PROPAGATOR) \
+                < environ_propagators.index(self._TRACECONTEXT_PROPAGATOR):
+                raise ValueError("tracecontext must be before solarwinds_propagator in OTEL_PROPAGATORS to use SolarWinds Observability.")
         environ[OTEL_PROPAGATORS] = ",".join(environ_propagators)
 
-        # Init and set CompositePropagator globally, like OTel API
-        propagators = []
-        for propagator in environ_propagators:
-            try:
-                propagators.append(
-                    next(
-                        iter_entry_points("opentelemetry_propagator", propagator)
-                    ).load()()
-                )
-            except Exception:
-                logger.exception(
-                    "Failed to load configured propagator `%s`", propagator
-                )
-                raise
-        set_global_textmap(CompositePropagator(propagators))
-
-        # Set global HTTP response propagator
-        set_global_response_propagator(SolarWindsTraceResponsePropagator())
+        logger.debug("Configured SolarWindsDistro: {}, {}, {}".format(
+            environ.get(OTEL_TRACES_SAMPLER),
+            environ.get(OTEL_TRACES_EXPORTER),
+            environ.get(OTEL_PROPAGATORS)
+        ))

Diff for: setup.cfg

@@ -25,7 +25,11 @@ install_requires =
 [options.entry_points]
 opentelemetry_distro =
     solarwinds_distro = opentelemetry_distro_solarwinds.distro:SolarWindsDistro
+opentelemetry_configurator =
+    solarwinds_configurator = opentelemetry_distro_solarwinds.configurator:SolarWindsConfigurator
 opentelemetry_propagator =
     solarwinds_propagator = opentelemetry_distro_solarwinds.propagator:SolarWindsPropagator
 opentelemetry_traces_exporter =
-    solarwinds_exporter = opentelemetry_distro_solarwinds.exporter:SolarWindsSpanExporter
+    solarwinds_exporter = opentelemetry_distro_solarwinds.exporter:SolarWindsSpanExporter
+opentelemetry_traces_sampler = 
+    solarwinds_sampler = opentelemetry_distro_solarwinds.sampler:ParentBasedSwSampler