Make metrics envvar constants private (open-telemetry#2255)

Author: aabmass

opentelemetry-api/src/opentelemetry/_metrics/__init__.py

@@ -49,7 +49,9 @@
     _ProxyObservableUpDownCounter,
     _ProxyUpDownCounter,
 )
-from opentelemetry.environment_variables import OTEL_PYTHON_METER_PROVIDER
+from opentelemetry.environment_variables import (
+    _OTEL_PYTHON_METER_PROVIDER as OTEL_PYTHON_METER_PROVIDER,
+)
 from opentelemetry.util._once import Once
 from opentelemetry.util._providers import _load_provider
 

opentelemetry-api/src/opentelemetry/environment_variables.py

@@ -37,12 +37,12 @@
 .. envvar:: OTEL_PYTHON_TRACER_PROVIDER
 """
 
-OTEL_PYTHON_METER_PROVIDER = "OTEL_PYTHON_METER_PROVIDER"
+_OTEL_PYTHON_METER_PROVIDER = "OTEL_PYTHON_METER_PROVIDER"
 """
 .. envvar:: OTEL_PYTHON_METER_PROVIDER
 """
 
-OTEL_METRICS_EXPORTER = "OTEL_METRICS_EXPORTER"
+_OTEL_METRICS_EXPORTER = "OTEL_METRICS_EXPORTER"
 """
 .. envvar:: OTEL_METRICS_EXPORTER
 

opentelemetry-api/tests/metrics/test_meter_provider.py

@@ -35,7 +35,9 @@
     _ProxyObservableUpDownCounter,
     _ProxyUpDownCounter,
 )
-from opentelemetry.environment_variables import OTEL_PYTHON_METER_PROVIDER
+from opentelemetry.environment_variables import (
+    _OTEL_PYTHON_METER_PROVIDER as OTEL_PYTHON_METER_PROVIDER,
+)
 from opentelemetry.test.globals_test import (
     MetricsGlobalsTest,
     reset_metrics_globals,