gotosocial/vendor/go.opentelemetry.io/otel/sdk/internal/x/x.go
2024-08-26 18:05:54 +02:00

67 lines
2.1 KiB
Go

// 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 // 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.ToLower(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
parse func(v string) (T, bool)
}
func newFeature[T any](suffix string, parse func(string) (T, bool)) Feature[T] {
const envKeyRoot = "OTEL_GO_X_"
return Feature[T]{
key: envKeyRoot + suffix,
parse: parse,
}
}
// Key returns the environment variable key that needs to be set to enable the
// feature.
func (f Feature[T]) Key() string { return f.key }
// 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.
vRaw := os.Getenv(f.key)
if vRaw == "" {
return v, ok
}
return f.parse(vRaw)
}
// Enabled returns if the feature is enabled.
func (f Feature[T]) Enabled() bool {
_, ok := f.Lookup()
return ok
}