func buildCustomTagsFromProvider(providerTags map[string]*telemetrypb.Tracing_CustomTag) []*tracing.CustomTag {
	var tags []*tracing.CustomTag
	for tagName, tagInfo := range providerTags {
		if tagInfo == nil {
			log.Warnf("while building custom tags from provider, encountered nil custom tag: %s, skipping", tagName)
			continue
		}
		switch tag := tagInfo.Type.(type) {
		case *telemetrypb.Tracing_CustomTag_Environment:

apiVersion: telemetry.istio.io/v1
kind: Telemetry
metadata:
  name: valid
spec:
  tracing:

[GOOS:plan9] env userconfig=$home/lib

go telemetry
stdout 'local'

go telemetry off
go telemetry
stdout 'off'
go env GOTELEMETRY
stdout 'off'

go telemetry local
go telemetry
stdout 'local'
go env GOTELEMETRY
stdout 'local'

go telemetry on
go telemetry
stdout 'on'
go env GOTELEMETRY
stdout 'on'

go env
stdout 'GOTELEMETRY=''?on''?'

apiVersion: telemetry.istio.io/v1alpha1
kind: Telemetry
metadata:
  name: valid
spec:
  tracing:

//go:build !cmd_go_bootstrap && !compiler_bootstrap

// Package telemetry is a shim package around the golang.org/x/telemetry
// and golang.org/x/telemetry/counter packages that has code build tagged
// out for cmd_go_bootstrap so that the bootstrap Go command does not
// depend on net (which is a dependency of golang.org/x/telemetry/counter
// on Windows).
package telemetry

import (
	"flag"
	"os"

	"golang.org/x/telemetry"

apiVersion: telemetry.istio.io/v1alpha1
kind: Telemetry
metadata:
  name: telemetry
  namespace: istio-system
spec:
  metrics:
  - providers:
    - name: prometheus
  accessLogging:
  - providers:
      - name: envoy-json
---
# Set up a Service associated with our proxy, which will run as 1.1.1.1 IP
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: proxy-service-instance
spec:
  hosts:

// Package telemetrycmd implements the "go telemetry" command.
package telemetrycmd

import (
	"context"
	"fmt"
	"os"

	"cmd/go/internal/base"
	"cmd/internal/telemetry"
)

var CmdTelemetry = &base.Command{
	UsageLine: "go telemetry [off|local|on]",
	Short:     "manage telemetry data and settings",
	Long: `Telemetry is used to manage Go telemetry data and settings.

Telemetry can be in one of three modes: off, local, or on.

	UseRealStackdriver bool
)

func init() {
	flag.DurationVar(&TelemetryRetryDelay, "istio.test.telemetry.retryDelay", time.Second*2, "Default retry delay used in tests")
	flag.DurationVar(&TelemetryRetryTimeout, "istio.test.telemetry.retryTimeout", time.Second*80, "Default retry timeout used in tests")
	flag.BoolVar(&UseRealStackdriver, "istio.test.telemetry.useRealStackdriver", false,

		"If true, pilot will add telemetry related metadata to cluster and endpoint resources, which will be consumed by telemetry filter.",
	).Get()

	EndpointTelemetryLabel = env.Register("PILOT_ENDPOINT_TELEMETRY_LABEL", true,
		"If true, pilot will add telemetry related metadata to Endpoint resource, which will be consumed by telemetry filter.",
	).Get()

					},
					Logging: telemetry.Spec.GetAccessLogging(),
				})
			}
			ts = append(ts, telemetry.Spec.GetTracing()...)
		}
	}

	if namespace != t.RootNamespace {
		telemetry := t.namespaceWideTelemetryConfig(namespace)
		if telemetry != (Telemetry{}) {
			key.Namespace = types.NamespacedName{Name: telemetry.Name, Namespace: telemetry.Namespace}
			ms = append(ms, telemetry.Spec.GetMetrics()...)