[surfacers.otel] Allow adding a prefix to metric names. (cloudprober#658

)

- Default prefix is cloudprober_.
- This is important to identify cloudprober metrics on the final
metrics system.

surfacers/internal/otel/otel.go

@@ -295,8 +295,8 @@ func (os *OtelSurfacer) convertMetric(em *metrics.EventMetrics, metricName strin
 
 	otelmetrics := func(data metricdata.Aggregation) metricdata.Metrics {
 		return metricdata.Metrics{
-			Name:        metricName,
-			Description: metricName + " metric for Cloudprober",
+			Name:        os.c.GetMetricsPrefix() + metricName,
+			Description: os.c.GetMetricsPrefix() + metricName + " metric for Cloudprober",
 			Unit:        unit,
 			Data:        data,
 		}

surfacers/internal/otel/otel_test.go

@@ -105,8 +105,8 @@ func TestOtelSurfacerWrite(t *testing.T) {
 				"probe.p1": {
 					Scope: instrumentation.Scope{Name: "probe.p1"},
 					Metrics: []metricdata.Metrics{
-						testMetric("failures", "1", sumData(dataPoint[int64](20, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
-						testMetric("latency", "us", sumData(dataPoint[float64](9.2, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
+						testMetric("cloudprober_failures", "1", sumData(dataPoint[int64](20, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
+						testMetric("cloudprober_latency", "us", sumData(dataPoint[float64](9.2, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
 					},
 				},
 			},
@@ -118,10 +118,10 @@ func TestOtelSurfacerWrite(t *testing.T) {
 				"probe.p2": {
 					Scope: instrumentation.Scope{Name: "probe.p2"},
 					Metrics: []metricdata.Metrics{
-						testMetric("resp_code", "1", sumData(
+						testMetric("cloudprober_resp_code", "1", sumData(
 							dataPoint[int64](2, [][2]string{{"probe", "p2"}, {"code", "200"}}, startTime, ems[1].Timestamp),
 							dataPoint[int64](1, [][2]string{{"probe", "p2"}, {"code", "500"}}, startTime, ems[1].Timestamp))),
-						testMetric("latency", "ms", metricdata.Histogram[float64]{
+						testMetric("cloudprober_latency", "ms", metricdata.Histogram[float64]{
 							DataPoints: []metricdata.HistogramDataPoint[float64]{
 								{
 									Attributes:   attribute.NewSet(attribute.String("probe", "p2")),
@@ -146,10 +146,10 @@ func TestOtelSurfacerWrite(t *testing.T) {
 				"probe.p1": {
 					Scope: instrumentation.Scope{Name: "probe.p1"},
 					Metrics: []metricdata.Metrics{
-						testMetric("failures", "1", sumData(dataPoint[int64](20, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
-						testMetric("latency", "us", sumData(dataPoint[float64](9.2, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
-						testMetric("failures", "1", sumData(dataPoint[int64](25, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp.Add(2*time.Second)))),
-						testMetric("latency", "us", sumData(dataPoint[float64](8.7, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp.Add(2*time.Second)))),
+						testMetric("cloudprober_failures", "1", sumData(dataPoint[int64](20, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
+						testMetric("cloudprober_latency", "us", sumData(dataPoint[float64](9.2, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp))),
+						testMetric("cloudprober_failures", "1", sumData(dataPoint[int64](25, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp.Add(2*time.Second)))),
+						testMetric("cloudprober_latency", "us", sumData(dataPoint[float64](8.7, [][2]string{{"probe", "p1"}}, startTime, ems[0].Timestamp.Add(2*time.Second)))),
 					},
 				},
 			},

surfacers/internal/otel/proto/config.proto

@@ -53,5 +53,11 @@ message SurfacerConf {
     GRPCExporter otlp_grpc_exporter = 2;
   }
 
+  // How often metrics will be exported. Note that metrics are accumulated
+  // internally and exported at this interval. Increasing this value will
+  // increase the memory usage.
   optional int32 export_interval_sec = 3 [default = 10];
+
+  // Prefix to use for metrics. Defaults to "cloudprober_".
+  optional string metrics_prefix = 4 [default = "cloudprober_"];
 }

surfacers/internal/otel/proto/config_proto_gen.cue

@@ -53,5 +53,12 @@ import "github.com/cloudprober/cloudprober/internal/tlsconfig/proto"
 		// OTLP gRPC exporter.
 		otlpGrpcExporter: #GRPCExporter @protobuf(2,GRPCExporter,name=otlp_grpc_exporter)
 	}
+
+	// How often metrics will be exported. Note that metrics are accumulated
+	// internally and exported at this interval. Increasing this value will
+	// increase the memory usage.
 	exportIntervalSec?: int32 @protobuf(3,int32,name=export_interval_sec,"default=10")
+
+	// Prefix to use for metrics. Defaults to "cloudprober_".
+	metricsPrefix?: string @protobuf(4,string,name=metrics_prefix,#"default="cloudprober_""#)
 }