},
			}, map[string]any{
				"key": "value",
			}),
			expected: "{\"ISTIO_VERSION\":\"fake\",\"key\":\"value\"}",
		},
		{
			testName: "discovery address",
			key:      "discovery_address",
			option:   option.DiscoveryAddress("fake"),
			expected: "fake",
		},
		{
			testName: "localhost v4",
			key:      "localhost",
			option:   option.Localhost(option.LocalhostIPv4),

	defaultDiscovery := config.DefaultConfig.DiscoveryAddress

	t.Run("apply single", func(t *testing.T) {
		mc, err := mesh.ApplyProxyConfig("discoveryAddress: foo", config)
		if err != nil {
			t.Fatal(err)
		}
		if mc.DefaultConfig.DiscoveryAddress != "foo" {
			t.Fatalf("expected discoveryAddress: foo, got %q", mc.DefaultConfig.DiscoveryAddress)
		}
	})

	t.Run("apply again", func(t *testing.T) {

}

func TestGetDNSNames(t *testing.T) {
	tests := []struct {
		name             string
		customHost       string
		discoveryAddress string
		revision         string
		sans             []string
	}{
		{
			name:             "no customHost",
			customHost:       "",
			discoveryAddress: "istiod.istio-system.svc.cluster.local",
			revision:         "default",
			sans: []string{
				"istio-pilot.istio-system.svc",

		pc.DrainDuration = nil
	}
	if proto.Equal(pc.TerminationDrainDuration, defaults.TerminationDrainDuration) {
		pc.TerminationDrainDuration = nil
	}
	if pc.DiscoveryAddress == defaults.DiscoveryAddress {
		pc.DiscoveryAddress = ""
	}
	if proto.Equal(pc.EnvoyMetricsService, defaults.EnvoyMetricsService) {
		pc.EnvoyMetricsService = nil
	}

	opts := make([]option.Instance, 0)

	opts = append(opts, option.ProxyConfig(config),
		option.Cluster(getServiceCluster(metadata)),
		option.PilotGRPCAddress(config.DiscoveryAddress),
		option.DiscoveryAddress(config.DiscoveryAddress),
		option.StatsdAddress(config.StatsdUdpAddress),
		option.XDSRootCert(metadata.XDSRootCert))

	// Add tracing options.
	if config.Tracing != nil {
		isH2 := false

  },
  "layered_runtime": {
      "layers": [
          {
            "name": "global config",

  },
  "layered_runtime": {
      "layers": [

accessLogFile: /dev/stdout
accessLogFormat: ""
defaultConfig:
  concurrency: 2
  configPath: ./etc/istio/proxy
  connectTimeout: 10s
  controlPlaneAuthPolicy: NONE
  discoveryAddress: istiod.istio-system.svc:15012
  drainDuration: 45s
  parentShutdownDuration: 1m0s
  proxyAdminPort: 15000
  proxyMetadata:
    DNS_AGENT: ""
  serviceCluster: istio-proxy
  tracing:
    zipkin:

  },
  "layered_runtime": {
      "layers": [
          {

        {{ end -}}
        - --drainDuration
        - "{{ formatDuration .ProxyConfig.DrainDuration }}"
        - --discoveryAddress
        - "{{ annotation .ObjectMeta `sidecar.istio.io/discoveryAddress` .ProxyConfig.DiscoveryAddress }}"
      {{- if eq .Values.global.proxy.tracer "lightstep" }}
        - --lightstepAddress
        - "{{ .ProxyConfig.GetTracing.GetLightstep.GetAddress }}"