otelconf: support OTEL_CONFIG_FILE as it is no longer experimental

CHANGELOG.md

@@ -8,10 +8,18 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- Configuration file can now be set via `OTEL_CONFIG_FILE` in `go.opentelemetry.io/contrib/otelconf`. (#8639)
+
 ### Fixed
 
 - Limit the request body size at 1MB in `go.opentelemetry.io/contrib/zpages`. (#8656)
 
+### Deprecated
+
+- `OTEL_EXPERIMENTAL_CONFIG_FILE` has been deprecated in favour of `OTEL_CONFIG_FILE` in `go.opentelemetry.io/contrib/otelconf`. (#8639)
+
 <!-- Released section -->
 <!-- Don't change this section unless doing release -->
 

otelconf/config.go

@@ -24,7 +24,10 @@ import (
 	"go.opentelemetry.io/contrib/otelconf/internal/provider"
 )
 
-const envVarConfigFile = "OTEL_EXPERIMENTAL_CONFIG_FILE"
+const (
+	envVarConfigFileDeprecated = "OTEL_EXPERIMENTAL_CONFIG_FILE"
+	envVarConfigFile           = "OTEL_CONFIG_FILE"
+)
 
 // SDK is a struct that contains all the providers
 // configured via the configuration model.
@@ -61,13 +64,16 @@ func (s *SDK) Shutdown(ctx context.Context) error {
 	return s.shutdown(ctx)
 }
 
-var noopSDK = SDK{
-	loggerProvider: nooplog.LoggerProvider{},
-	meterProvider:  noopmetric.MeterProvider{},
-	tracerProvider: nooptrace.TracerProvider{},
-	propagator:     propagation.NewCompositeTextMapPropagator(),
-	shutdown:       func(context.Context) error { return nil },
-}
+var (
+	noopSDK = SDK{
+		loggerProvider: nooplog.LoggerProvider{},
+		meterProvider:  noopmetric.MeterProvider{},
+		tracerProvider: nooptrace.TracerProvider{},
+		propagator:     propagation.NewCompositeTextMapPropagator(),
+		shutdown:       func(context.Context) error { return nil },
+	}
+	errDeprecatedEnvVarUsed = errors.New("OTEL_EXPERIMENTAL_CONFIG_FILE is no longer supported, use OTEL_CONFIG_FILE instead")
+)
 
 func parseConfigFileFromEnvironment(filename string) (ConfigurationOption, error) {
 	b, err := os.ReadFile(filename)
@@ -86,10 +92,14 @@ func parseConfigFileFromEnvironment(filename string) (ConfigurationOption, error
 }
 
 // NewSDK creates SDK providers based on the configuration model. It checks the local environment and
-// uses the file set in the variable `OTEL_EXPERIMENTAL_CONFIG_FILE` to configure the SDK automatically.
-// Any file defined by `OTEL_EXPERIMENTAL_CONFIG_FILE` will supersede all files passed with
+// uses the file set in the variable `OTEL_CONFIG_FILE` to configure the SDK automatically.
+// Any file defined by `OTEL_CONFIG_FILE` will supersede all files passed with
 // [WithOpenTelemetryConfiguration].
 func NewSDK(opts ...ConfigurationOption) (SDK, error) {
+	_, ok := os.LookupEnv(envVarConfigFileDeprecated)
+	if ok {
+		return noopSDK, errDeprecatedEnvVarUsed
+	}
 	filename, ok := os.LookupEnv(envVarConfigFile)
 	if ok {
 		opt, err := parseConfigFileFromEnvironment(filename)

otelconf/config_test.go

@@ -428,6 +428,10 @@ func TestNewSDKWithEnvVar(t *testing.T) {
 	t.Setenv(envVarConfigFile, filepath.Join("testdata", "v1.0.0.yaml"))
 	_, err = NewSDK(cfg...)
 	require.ErrorIs(t, err, newErrInvalid("otlp_file/development"))
+	// validate that use of deprecated env var returns an error
+	t.Setenv(envVarConfigFileDeprecated, filepath.Join("testdata", "v1.0.0.yaml"))
+	_, err = NewSDK(cfg...)
+	require.ErrorIs(t, err, errDeprecatedEnvVarUsed)
 }
 
 var v10OpenTelemetryConfig = OpenTelemetryConfiguration{