fix: add resource_attributes_as_tags support prometheusexporter

exporter/prometheusexporter/README.md

@@ -17,6 +17,8 @@ The following settings can be optionally configured:
 - `send_timestamps` (default = `false`): if true, sends the timestamp of the underlying
   metric sample in the response.
 - `metric_expiration` (default = `5m`): defines how long metrics are exposed without updates
+- `resource_attributes_as_tag` (default = `false`): if set to true will transform all resource
+  attributes into labels.
 
 Example:
 
@@ -30,4 +32,5 @@ exporters:
       "another label": spaced value
     send_timestamps: true
     metric_expiration: 180m
+	resource_attributes_as_tags: true
 ```

exporter/prometheusexporter/config.go

@@ -40,4 +40,8 @@ type Config struct {
 
 	// MetricExpiration defines how long metrics are kept without updates
 	MetricExpiration time.Duration `mapstructure:"metric_expiration"`
+
+	// ResourceAttributesAsTags, if sMet to true, will use the exporterhelper feature to
+	// transform all resource attributes into metric labels.
+	ResourceAttributesAsTags bool `mapstructure:"resource_attributes_as_tags"`
 }

exporter/prometheusexporter/factory.go

@@ -52,5 +52,19 @@ func createMetricsExporter(
 ) (component.MetricsExporter, error) {
 	pcfg := cfg.(*Config)
 
-	return newPrometheusExporter(pcfg, params.Logger)
+	exporter, err := newPrometheusExporter(pcfg, params.Logger)
+	if err != nil {
+		return nil, err
+	}
+
+	return exporterhelper.NewMetricsExporter(
+		cfg,
+		params.Logger,
+		exporter.ConsumeMetrics,
+		exporterhelper.WithStart(exporter.Start),
+		exporterhelper.WithShutdown(exporter.Shutdown),
+		exporterhelper.WithResourceToTelemetryConversion(exporterhelper.ResourceToTelemetrySettings{
+			Enabled: pcfg.ResourceAttributesAsTags,
+		}),
+	)
 }