chore: sdk/internal/x - generate x package from shared template (#7495)

Closes #7384 - Add sdk/internal/gen.go with gotmpl directives to generate x/x.go and x/x_test.go - Refactor sdk/internal/x/x.go to generic Feature[T] with multi-key support and Keys() - Move Resource feature into sdk/internal/x/features.go (case-insensitive true enables) - Add tests: generic feature tests in x_test.go and Resource tests in features_test.go - Aligns with sdk/log/internal/x pattern introduced in PR #7389 Internal note: replaces Key() with Keys() for internal Feature API. Build and lints pass --------- Co-authored-by: Damien Mathieu <42@dmathieu.com>
2025-10-31 00:07:40 +02:00 · 2025-10-16 12:53:17 +05:30
parent b37822be24
commit f346decaf6
14 changed files with 115 additions and 262 deletions
--- a/sdk/internal/gen.go
+++ b/sdk/internal/gen.go
@@ -0,0 +1,8 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package internal provides internal functionality for the sdk package.
+package internal // import "go.opentelemetry.io/otel/sdk/internal"
+
+//go:generate gotmpl --body=../../internal/shared/x/x.go.tmpl "--data={ \"pkg\": \"go.opentelemetry.io/otel/sdk\" }" --out=x/x.go
+//go:generate gotmpl --body=../../internal/shared/x/x_test.go.tmpl "--data={}" --out=x/x_test.go
--- a/sdk/internal/x/features.go
+++ b/sdk/internal/x/features.go
@@ -0,0 +1,39 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package x documents experimental features for [go.opentelemetry.io/otel/sdk].
+package x // import "go.opentelemetry.io/otel/sdk/internal/x"
+
+import "strings"
+
+// Resource is an experimental feature flag that defines if resource detectors
+// should be included experimental semantic conventions.
+//
+// To enable this feature set the OTEL_GO_X_RESOURCE environment variable
+// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
+// will also enable this).
+var Resource = newFeature(
+	[]string{"RESOURCE"},
+	func(v string) (string, bool) {
+		if strings.EqualFold(v, "true") {
+			return v, true
+		}
+		return "", false
+	},
+)
+
+// Observability is an experimental feature flag that determines if SDK
+// observability metrics are enabled.
+//
+// To enable this feature set the OTEL_GO_X_OBSERVABILITY environment variable
+// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
+// will also enable this).
+var Observability = newFeature(
+	[]string{"OBSERVABILITY", "SELF_OBSERVABILITY"},
+	func(v string) (string, bool) {
+		if strings.EqualFold(v, "true") {
+			return v, true
+		}
+		return "", false
+	},
+)
--- a/sdk/internal/x/features_test.go
+++ b/sdk/internal/x/features_test.go
@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package x
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestResource(t *testing.T) {
+	const key = "OTEL_GO_X_RESOURCE"
+	require.Contains(t, Resource.Keys(), key)
+
+	t.Run("100", run(setenv(key, "100"), assertDisabled(Resource)))
+	t.Run("true", run(setenv(key, "true"), assertEnabled(Resource, "true")))
+	t.Run("True", run(setenv(key, "True"), assertEnabled(Resource, "True")))
+	t.Run("false", run(setenv(key, "false"), assertDisabled(Resource)))
+	t.Run("empty", run(assertDisabled(Resource)))
+}
--- a/sdk/internal/x/x.go
+++ b/sdk/internal/x/x.go
@@ -1,48 +1,38 @@
+// Code generated by gotmpl. DO NOT MODIFY.
+// source: internal/shared/x/x.go.tmpl
+
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0

-// Package x contains support for OTel SDK experimental features.
-//
-// This package should only be used for features defined in the specification.
-// It should not be used for experiments or new project ideas.
+// Package x documents experimental features for [go.opentelemetry.io/otel/sdk].
 package x // import "go.opentelemetry.io/otel/sdk/internal/x"

 import (
 	"os"
-	"strings"
 )

-// Resource is an experimental feature flag that defines if resource detectors
-// should be included experimental semantic conventions.
-//
-// To enable this feature set the OTEL_GO_X_RESOURCE environment variable
-// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
-// will also enable this).
-var Resource = newFeature("RESOURCE", func(v string) (string, bool) {
-	if strings.EqualFold(v, "true") {
-		return v, true
-	}
-	return "", false
-})
-
 // Feature is an experimental feature control flag. It provides a uniform way
 // to interact with these feature flags and parse their values.
 type Feature[T any] struct {
-	key   string
+	keys  []string
 	parse func(v string) (T, bool)
 }

-func newFeature[T any](suffix string, parse func(string) (T, bool)) Feature[T] {
+func newFeature[T any](suffix []string, parse func(string) (T, bool)) Feature[T] {
 	const envKeyRoot = "OTEL_GO_X_"
+	keys := make([]string, 0, len(suffix))
+	for _, s := range suffix {
+		keys = append(keys, envKeyRoot+s)
+	}
 	return Feature[T]{
-		key:   envKeyRoot + suffix,
+		keys:  keys,
 		parse: parse,
 	}
 }

-// Key returns the environment variable key that needs to be set to enable the
+// Keys returns the environment variable keys that can be set to enable the
 // feature.
-func (f Feature[T]) Key() string { return f.key }
+func (f Feature[T]) Keys() []string { return f.keys }

 // Lookup returns the user configured value for the feature and true if the
 // user has enabled the feature. Otherwise, if the feature is not enabled, a
@@ -52,11 +42,13 @@ func (f Feature[T]) Lookup() (v T, ok bool) {
 	//
 	// > The SDK MUST interpret an empty value of an environment variable the
 	// > same way as when the variable is unset.
-	vRaw := os.Getenv(f.key)
-	if vRaw == "" {
-		return v, ok
+	for _, key := range f.keys {
+		vRaw := os.Getenv(key)
+		if vRaw != "" {
+			return f.parse(vRaw)
+		}
 	}
-	return f.parse(vRaw)
+	return v, ok
 }

 // Enabled reports whether the feature is enabled.
--- a/sdk/internal/x/x_test.go
+++ b/sdk/internal/x/x_test.go
@@ -1,25 +1,40 @@
+// Code generated by gotmpl. DO NOT MODIFY.
+// source: internal/shared/x/x_text.go.tmpl
+
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0

 package x

 import (
+	"strings"
 	"testing"

 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )

-func TestResource(t *testing.T) {
-	const key = "OTEL_GO_X_RESOURCE"
-	require.Equal(t, key, Resource.Key())
+const (
+	mockKey  = "OTEL_GO_X_MOCK_FEATURE"
+	mockKey2 = "OTEL_GO_X_MOCK_FEATURE2"
+)

-	t.Run("true", run(setenv(key, "true"), assertEnabled(Resource, "true")))
-	t.Run("True", run(setenv(key, "True"), assertEnabled(Resource, "True")))
-	t.Run("TRUE", run(setenv(key, "TRUE"), assertEnabled(Resource, "TRUE")))
-	t.Run("false", run(setenv(key, "false"), assertDisabled(Resource)))
-	t.Run("1", run(setenv(key, "1"), assertDisabled(Resource)))
-	t.Run("empty", run(assertDisabled(Resource)))
+var mockFeature = newFeature([]string{"MOCK_FEATURE", "MOCK_FEATURE2"}, func(v string) (string, bool) {
+	if strings.EqualFold(v, "true") {
+		return v, true
+	}
+	return "", false
+})
+
+func TestFeature(t *testing.T) {
+	require.Contains(t, mockFeature.Keys(), mockKey)
+	require.Contains(t, mockFeature.Keys(), mockKey2)
+
+	t.Run("100", run(setenv(mockKey, "100"), assertDisabled(mockFeature)))
+	t.Run("true", run(setenv(mockKey, "true"), assertEnabled(mockFeature, "true")))
+	t.Run("True", run(setenv(mockKey, "True"), assertEnabled(mockFeature, "True")))
+	t.Run("false", run(setenv(mockKey, "false"), assertDisabled(mockFeature)))
+	t.Run("empty", run(assertDisabled(mockFeature)))
 }

 func run(steps ...func(*testing.T)) func(*testing.T) {
@@ -31,7 +46,7 @@ func run(steps ...func(*testing.T)) func(*testing.T) {
 	}
 }

-func setenv(k, v string) func(t *testing.T) { //nolint:unparam
+func setenv(k, v string) func(t *testing.T) { //nolint:unparam // This is a reusable test utility function.
 	return func(t *testing.T) { t.Setenv(k, v) }
 }

--- a/sdk/trace/doc.go
+++ b/sdk/trace/doc.go
@@ -7,7 +7,7 @@ Package trace contains support for OpenTelemetry distributed tracing.
 The following assumes a basic familiarity with OpenTelemetry concepts.
 See https://opentelemetry.io.

-See [go.opentelemetry.io/otel/sdk/trace/internal/x] for information about
+See [go.opentelemetry.io/otel/sdk/internal/x] for information about
 the experimental features.
 */
 package trace // import "go.opentelemetry.io/otel/sdk/trace"
--- a/sdk/trace/internal/gen.go
+++ b/sdk/trace/internal/gen.go
@@ -1,8 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-// Package internal provides internal functionality for the sdk/trace package.
-package internal // import "go.opentelemetry.io/otel/sdk/trace/internal"
-
-//go:generate gotmpl --body=../../../internal/shared/x/x.go.tmpl "--data={ \"pkg\": \"go.opentelemetry.io/otel/sdk/trace\" }" --out=x/x.go
-//go:generate gotmpl --body=../../../internal/shared/x/x_test.go.tmpl "--data={}" --out=x/x_test.go
--- a/sdk/trace/internal/observ/batch_span_processor.go
+++ b/sdk/trace/internal/observ/batch_span_processor.go
@@ -12,7 +12,7 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk"
-	"go.opentelemetry.io/otel/sdk/trace/internal/x"
+	"go.opentelemetry.io/otel/sdk/internal/x"
 	semconv "go.opentelemetry.io/otel/semconv/v1.37.0"
 	"go.opentelemetry.io/otel/semconv/v1.37.0/otelconv"
 )
--- a/sdk/trace/internal/observ/tracer.go
+++ b/sdk/trace/internal/observ/tracer.go
@@ -12,7 +12,7 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk"
-	"go.opentelemetry.io/otel/sdk/trace/internal/x"
+	"go.opentelemetry.io/otel/sdk/internal/x"
 	"go.opentelemetry.io/otel/semconv/v1.37.0/otelconv"
 	"go.opentelemetry.io/otel/trace"
 )
--- a/sdk/trace/internal/x/README.md
+++ b/sdk/trace/internal/x/README.md
@@ -1,35 +0,0 @@
-# Experimental Features
-
-The Trace SDK contains features that have not yet stabilized in the OpenTelemetry specification.
-These features are added to the OpenTelemetry Go Trace SDK prior to stabilization in the specification so that users can start experimenting with them and provide feedback.
-
-These features may change in backwards incompatible ways as feedback is applied.
-See the [Compatibility and Stability](#compatibility-and-stability) section for more information.
-
-## Features
-
- [Observability](#observability)
-
-### Observability
-
-The SDK can be configured to provide observability about itself using OpenTelemetry metrics.
-
-To opt-in, set the environment variable `OTEL_GO_X_OBSERVABILITY` to `true`.
-
-When enabled, the SDK will create the following metrics using the global `MeterProvider`:
-
- `otel.sdk.span.live`
- `otel.sdk.span.started`
-
-Please see the [Semantic conventions for OpenTelemetry SDK metrics] documentation for more details on these metrics.
-
-[Semantic conventions for OpenTelemetry SDK metrics]: https://github.com/open-telemetry/semantic-conventions/blob/v1.36.0/docs/otel/sdk-metrics.md
-
-## Compatibility and Stability
-
-Experimental features do not fall within the scope of the OpenTelemetry Go versioning and stability [policy](../../../../VERSIONING.md).
-These features may be removed or modified in successive version releases, including patch versions.
-
-When an experimental feature is promoted to a stable feature, a migration path will be included in the changelog entry of the release.
-There is no guarantee that any environment variable feature flags that enabled the experimental feature will be supported by the stable version.
-If they are supported, they may be accompanied with a deprecation notice stating a timeline for the removal of that support.
--- a/sdk/trace/internal/x/features.go
+++ b/sdk/trace/internal/x/features.go
@@ -1,22 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package x // import "go.opentelemetry.io/otel/sdk/trace/internal/x"
-
-import "strings"
-
-// Observability is an experimental feature flag that determines if SDK
-// observability metrics are enabled.
-//
-// To enable this feature set the OTEL_GO_X_OBSERVABILITY environment variable
-// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
-// will also enable this).
-var Observability = newFeature(
-	[]string{"OBSERVABILITY", "SELF_OBSERVABILITY"},
-	func(v string) (string, bool) {
-		if strings.EqualFold(v, "true") {
-			return v, true
-		}
-		return "", false
-	},
-)
--- a/sdk/trace/internal/x/features_test.go
+++ b/sdk/trace/internal/x/features_test.go
@@ -1,24 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package x
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestObservability(t *testing.T) {
-	const key = "OTEL_GO_X_OBSERVABILITY"
-	require.Contains(t, Observability.Keys(), key)
-
-	const altKey = "OTEL_GO_X_SELF_OBSERVABILITY"
-	require.Contains(t, Observability.Keys(), altKey)
-
-	t.Run("100", run(setenv(key, "100"), assertDisabled(Observability)))
-	t.Run("true", run(setenv(key, "true"), assertEnabled(Observability, "true")))
-	t.Run("True", run(setenv(key, "True"), assertEnabled(Observability, "True")))
-	t.Run("false", run(setenv(key, "false"), assertDisabled(Observability)))
-	t.Run("empty", run(assertDisabled(Observability)))
-}
--- a/sdk/trace/internal/x/x.go
+++ b/sdk/trace/internal/x/x.go
@@ -1,58 +0,0 @@
-// Code generated by gotmpl. DO NOT MODIFY.
-// source: internal/shared/x/x.go.tmpl
-
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-// Package x documents experimental features for [go.opentelemetry.io/otel/sdk/trace].
-package x // import "go.opentelemetry.io/otel/sdk/trace/internal/x"
-
-import (
-	"os"
-)
-
-// Feature is an experimental feature control flag. It provides a uniform way
-// to interact with these feature flags and parse their values.
-type Feature[T any] struct {
-	keys  []string
-	parse func(v string) (T, bool)
-}
-
-func newFeature[T any](suffix []string, parse func(string) (T, bool)) Feature[T] {
-	const envKeyRoot = "OTEL_GO_X_"
-	keys := make([]string, 0, len(suffix))
-	for _, s := range suffix {
-		keys = append(keys, envKeyRoot+s)
-	}
-	return Feature[T]{
-		keys:  keys,
-		parse: parse,
-	}
-}
-
-// Keys returns the environment variable keys that can be set to enable the
-// feature.
-func (f Feature[T]) Keys() []string { return f.keys }
-
-// Lookup returns the user configured value for the feature and true if the
-// user has enabled the feature. Otherwise, if the feature is not enabled, a
-// zero-value and false are returned.
-func (f Feature[T]) Lookup() (v T, ok bool) {
-	// https://github.com/open-telemetry/opentelemetry-specification/blob/62effed618589a0bec416a87e559c0a9d96289bb/specification/configuration/sdk-environment-variables.md#parsing-empty-value
-	//
-	// > The SDK MUST interpret an empty value of an environment variable the
-	// > same way as when the variable is unset.
-	for _, key := range f.keys {
-		vRaw := os.Getenv(key)
-		if vRaw != "" {
-			return f.parse(vRaw)
-		}
-	}
-	return v, ok
-}
-
-// Enabled reports whether the feature is enabled.
-func (f Feature[T]) Enabled() bool {
-	_, ok := f.Lookup()
-	return ok
-}
--- a/sdk/trace/internal/x/x_test.go
+++ b/sdk/trace/internal/x/x_test.go
@@ -1,75 +0,0 @@
-// Code generated by gotmpl. DO NOT MODIFY.
-// source: internal/shared/x/x_text.go.tmpl
-
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package x
-
-import (
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-const (
-	mockKey  = "OTEL_GO_X_MOCK_FEATURE"
-	mockKey2 = "OTEL_GO_X_MOCK_FEATURE2"
-)
-
-var mockFeature = newFeature([]string{"MOCK_FEATURE", "MOCK_FEATURE2"}, func(v string) (string, bool) {
-	if strings.EqualFold(v, "true") {
-		return v, true
-	}
-	return "", false
-})
-
-func TestFeature(t *testing.T) {
-	require.Contains(t, mockFeature.Keys(), mockKey)
-	require.Contains(t, mockFeature.Keys(), mockKey2)
-
-	t.Run("100", run(setenv(mockKey, "100"), assertDisabled(mockFeature)))
-	t.Run("true", run(setenv(mockKey, "true"), assertEnabled(mockFeature, "true")))
-	t.Run("True", run(setenv(mockKey, "True"), assertEnabled(mockFeature, "True")))
-	t.Run("false", run(setenv(mockKey, "false"), assertDisabled(mockFeature)))
-	t.Run("empty", run(assertDisabled(mockFeature)))
-}
-
-func run(steps ...func(*testing.T)) func(*testing.T) {
-	return func(t *testing.T) {
-		t.Helper()
-		for _, step := range steps {
-			step(t)
-		}
-	}
-}
-
-func setenv(k, v string) func(t *testing.T) { //nolint:unparam // This is a reusable test utility function.
-	return func(t *testing.T) { t.Setenv(k, v) }
-}
-
-func assertEnabled[T any](f Feature[T], want T) func(*testing.T) {
-	return func(t *testing.T) {
-		t.Helper()
-		assert.True(t, f.Enabled(), "not enabled")
-
-		v, ok := f.Lookup()
-		assert.True(t, ok, "Lookup state")
-		assert.Equal(t, want, v, "Lookup value")
-	}
-}
-
-func assertDisabled[T any](f Feature[T]) func(*testing.T) {
-	var zero T
-	return func(t *testing.T) {
-		t.Helper()
-
-		assert.False(t, f.Enabled(), "enabled")
-
-		v, ok := f.Lookup()
-		assert.False(t, ok, "Lookup state")
-		assert.Equal(t, zero, v, "Lookup value")
-	}
-}