feat: Use OTel distro class to configure SDK - allow both programatic…

… and auto-configure hooks (#22)

## Which problem is this PR solving?
Updates the distro to introduce a the HoneycombDistro class which
introduces the hook for auto configuration via BaseDistro. Also exposes
the `configure_opentelemetry` function that can be used programatically
to configure the SDK.

- Closes #10 

## Short description of the changes
- Adds new HoneycombDistro class that depends on BaseDistro
- Adds `configure_opentelemetry` function that sets up the OTel SDK via
environment variables
- Adds unit tests for the distro to verify API key, endpoint and service
name can be set via parameter or env var

NOTE: env vars are used over parameters

Co-authored-by: Mike Goldsmth <goldsmith.mike@gmail.com>

examples/hello-world-flask/app.py

@@ -1,8 +1,8 @@
 from flask import Flask
 from opentelemetry import trace
-from src.honeycomb.opentelemetry import hello
-# todo: how to not include the src in imports /
-# is this because a local dep? or bc the parent pyproject.toml config?
+from honeycomb.opentelemetry import configure_opentelemetry
+
+configure_opentelemetry()
 
 app = Flask(__name__)
 
@@ -12,4 +12,4 @@ def hello_world():
     with trace.get_tracer(__name__).start_as_current_span("foo"):
         with trace.get_tracer(__name__).start_as_current_span("bar"):
             print("baz")
-    return hello.hello_world()
+    return "Hello World"

examples/hello-world-flask/pyproject.toml

@@ -12,7 +12,7 @@ opentelemetry-instrumentation = "^0.35b0"
 opentelemetry-distro = "^0.35b0"
 opentelemetry-instrumentation-flask = "^0.35b0"
 opentelemetry-exporter-otlp-proto-grpc = "^1.14.0"
-honeycomb-opentelemetry-python = {path = "../../", develop = true}
+honeycomb-opentelemetry = {path = "../../", develop = true}
 
 [build-system]
 requires = ["poetry-core"]

honeycomb/opentelemetry/__init__.py

@@ -0,0 +1 @@
+from honeycomb.opentelemetry.distro import configure_opentelemetry

honeycomb/opentelemetry/distro.py

@@ -0,0 +1,58 @@
+"""
+Add module doc string
+"""
+import os
+from opentelemetry.instrumentation.distro import BaseDistro
+from opentelemetry.environment_variables import OTEL_TRACES_EXPORTER, OTEL_METRICS_EXPORTER
+from opentelemetry.sdk.environment_variables import (
+    OTEL_SERVICE_NAME,
+    OTEL_EXPORTER_OTLP_PROTOCOL,
+    OTEL_EXPORTER_OTLP_HEADERS,
+    OTEL_EXPORTER_OTLP_ENDPOINT
+)
+
+HONEYCOMB_API_KEY = "HONEYCOMB_API_KEY"
+HONEYCOMB_API_ENDPOINT = "HONEYCOMB_API_ENDPOINT"
+
+DEFAULT_API_ENDPOINT = "api.honeycomb.io:443"
+DEFAULT_SERVICE_NAME = "unknown_service:python"
+
+
+def configure_opentelemetry(
+    apikey: str = None,
+    service_name: str = None,
+    endpoint: str = None
+):
+    os.environ.setdefault(OTEL_EXPORTER_OTLP_PROTOCOL, "grpc")
+    os.environ.setdefault(OTEL_TRACES_EXPORTER, "otlp")
+    # disable metrics for now
+    os.environ.setdefault(OTEL_METRICS_EXPORTER, "none")
+
+    service_name = os.environ.get(OTEL_SERVICE_NAME, service_name)
+    if not service_name:
+        # TODO - warn no service name set, defaulting to unknown_service:python
+        service_name = DEFAULT_SERVICE_NAME
+    os.environ.setdefault(OTEL_SERVICE_NAME, service_name)
+
+    endpoint = os.environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, endpoint)
+    if not endpoint:
+        endpoint = DEFAULT_API_ENDPOINT
+    os.environ.setdefault(OTEL_EXPORTER_OTLP_ENDPOINT, endpoint)
+
+    apikey = os.environ.get(HONEYCOMB_API_KEY, apikey)
+    if apikey:
+        os.environ.setdefault(OTEL_EXPORTER_OTLP_HEADERS,
+                              f"x-honeycomb-team={apikey}")
+    else:
+        # TODO - warn no API key set
+        pass
+
+
+class HoneycombDistro(BaseDistro):
+    """
+    The OpenTelemetry provided Distro configures a default set of
+    configuration out of the box.
+    """
+
+    def _configure(self, **kwargs):
+        configure_opentelemetry()

pyproject.toml

@@ -1,13 +1,15 @@
 [tool.poetry]
-name = "honeycomb-opentelemetry-python"
+name = "honeycomb-opentelemetry"
 version = "0.1.0"
 description = "Honeycomb OpenTelemetry Distro for Python"
 authors = ["Honeycomb <support@honeycomb.io>"]
 readme = "README.md"
-packages = [{include = "src"}]
+packages = [{include = "honeycomb" }]
 
 [tool.poetry.dependencies]
 python = "^3.10"
+opentelemetry-instrumentation = "^0.35b0"
+opentelemetry-sdk = "^1.14.0"
 
 [tool.poetry.group.dev.dependencies]
 coverage = "^6.5.0"
@@ -18,9 +20,3 @@ pycodestyle = "^2.10.0"
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
-
-[tool.pytest.ini_options]
-pythonpath = "src"
-addopts = [
-    "--import-mode=importlib",
-]