Set options.UserAgent so that the OpenCensus exporter does not overri… (

#1620)

* Set options.UserAgent so that the OpenCensus exporter does not override the UA

* Add comments to clarify how user agent settings are used

* Fix comments

exporter/stackdriverexporter/stackdriver.go

@@ -65,18 +65,23 @@ func (me *metricsExporter) Shutdown(context.Context) error {
  return nil
 }
 
-func generateClientOptions(cfg *Config, version string) ([]option.ClientOption, error) {
- userAgent := strings.ReplaceAll(cfg.UserAgent, "{{version}}", version)
+func setVersionInUserAgent(cfg *Config, version string) {
+ cfg.UserAgent = strings.ReplaceAll(cfg.UserAgent, "{{version}}", version)
+}
+
+func generateClientOptions(cfg *Config) ([]option.ClientOption, error) {
  var copts []option.ClientOption
- if userAgent != "" {
- copts = append(copts, option.WithUserAgent(userAgent))
+ // option.WithUserAgent is used by the Trace exporter, but not the Metric exporter (see comment below)
+ if cfg.UserAgent != "" {
+ copts = append(copts, option.WithUserAgent(cfg.UserAgent))
  }
  if cfg.Endpoint != "" {
  if cfg.UseInsecure {
- // WithGRPCConn option takes precedent over all other supplied options so need to provide user agent here as well
+ // option.WithGRPCConn option takes precedent over all other supplied options so the
+ // following user agent will be used by both exporters if we reach this branch
  var dialOpts []grpc.DialOption
- if userAgent != "" {
- dialOpts = append(dialOpts, grpc.WithUserAgent(userAgent))
+ if cfg.UserAgent != "" {
+ dialOpts = append(dialOpts, grpc.WithUserAgent(cfg.UserAgent))
  }
  conn, err := grpc.Dial(cfg.Endpoint, append(dialOpts, grpc.WithInsecure())...)
  if err != nil {
@@ -94,12 +99,14 @@ func generateClientOptions(cfg *Config, version string) ([]option.ClientOption,
 }
 
 func newStackdriverTraceExporter(cfg *Config, params component.ExporterCreateParams) (component.TracesExporter, error) {
+ setVersionInUserAgent(cfg, params.ApplicationStartInfo.Version)
+
  topts := []cloudtrace.Option{
  cloudtrace.WithProjectID(cfg.ProjectID),
  cloudtrace.WithTimeout(cfg.Timeout),
  }
 
- copts, err := generateClientOptions(cfg, params.ApplicationStartInfo.Version)
+ copts, err := generateClientOptions(cfg)
  if err != nil {
  return nil, err
  }
@@ -184,6 +191,8 @@ func validateAndAppendDurationOption(topts []cloudtrace.Option, name string, val
 }
 
 func newStackdriverMetricsExporter(cfg *Config, params component.ExporterCreateParams) (component.MetricsExporter, error) {
+ setVersionInUserAgent(cfg, params.ApplicationStartInfo.Version)
+
  // TODO: For each ProjectID, create a different exporter
  // or at least a unique Stackdriver client per ProjectID.
  options := stackdriver.Options{
@@ -199,7 +208,12 @@ func newStackdriverMetricsExporter(cfg *Config, params component.ExporterCreateP
  Timeout: cfg.Timeout,
  }
 
- copts, err := generateClientOptions(cfg, params.ApplicationStartInfo.Version)
+ // note options.UserAgent overrides the option.WithUserAgent client option in the Metric exporter
+ if cfg.UserAgent != "" {
+ options.UserAgent = cfg.UserAgent
+ }
+
+ copts, err := generateClientOptions(cfg)
  if err != nil {
  return nil, err
  }