Name: "envoy-json",
		Provider: &meshconfig.MeshConfig_ExtensionProvider_EnvoyFileAccessLog{
			EnvoyFileAccessLog: &meshconfig.MeshConfig_ExtensionProvider_EnvoyFileAccessLogProvider{
				Path: "/dev/stdout",
				LogFormat: &meshconfig.MeshConfig_ExtensionProvider_EnvoyFileAccessLogProvider_LogFormat{
					LogFormat: &meshconfig.MeshConfig_ExtensionProvider_EnvoyFileAccessLogProvider_LogFormat_Labels{
						Labels: &structpb.Struct{},

		expected   *accesslog.AccessLog
	}{
		{
			name: "stdout",
			meshConfig: &meshconfig.MeshConfig{
				AccessLogEncoding: meshconfig.MeshConfig_TEXT,
			},
			fp: stdoutFormat,
			expected: &accesslog.AccessLog{
				Name:       wellknown.FileAccessLog,
				ConfigType: &accesslog.AccessLog_TypedConfig{TypedConfig: protoconv.MessageToAny(stdout)},
			},
		},
		{
			name: "stderr",

	if err != nil {
		return err
	}

	// Do a zero-byte write to stdout before handing off to the container runtime.
	// This ensures at least one Write call is made to the writer when copying starts,
	// even if we then block waiting for log output from the container.
	if _, err := stdout.Write([]byte{}); err != nil {
		return err
	}

	metadataCommandOperator        = "%METADATA"
	celCommandOperator             = "%CEL"
	// count of all supported fotmatter, right now is 3(CEL, METADATA and REQ_WITHOUT_QUERY).
	maxFormattersLength = 3

	DevStdout = "/dev/stdout"

	builtinEnvoyAccessLogProvider = "envoy"
)

var (
	// this is used for testing. it should not be changed in regular code.
	clusterLookupFn = LookupCluster