Add metric for instrumented processes

docs/sources/metrics.md

@@ -109,3 +109,4 @@ Beyla can be [configured to report internal metrics]({{< relref "./configure/opt
 | `otel_trace_exports` | Counter | Length of the trace batches submitted to the remote OTEL collector |
 | `otel_trace_export_errors` | CounterVec | Error count on each failed OTEL trace export, by error type |
 | `prometheus_http_requests` | CounterVec | Number of requests towards the Prometheus Scrape endpoint, faceted by HTTP port and path |
+| `beyla_discovered_services` | GaugeVec | Discovered services by Beyla, with process name |

pkg/internal/discover/attacher.go

@@ -95,6 +95,7 @@ func (ta *TraceAttacher) getTracer(ie *Instrumentable) (*ebpf.ProcessTracer, boo
  ta.log.Debug(".done")
  return nil, false
  }
+ ta.Metrics.DiscoverService(ie.FileInfo.ExecutableName())
  ta.log.Info("instrumenting process", "cmd", ie.FileInfo.CmdExePath, "pid", ie.FileInfo.Pid)
 
  // builds a tracer for that executable
@@ -205,6 +206,7 @@ func (ta *TraceAttacher) notifyProcessDeletion(ie *Instrumentable) {
  // notifying the tracer to block any trace from that PID
  // to avoid that a new process reusing this PID could send traces
  // unless explicitly allowed
+ ta.Metrics.UndiscoverService(ie.FileInfo.ExecutableName())
  tracer.BlockPID(uint32(ie.FileInfo.Pid), ie.FileInfo.Ns)
 
  // if there are no more trace instances for a Go program, we need to notify that

pkg/internal/imetrics/imetrics.go

@@ -28,6 +28,10 @@ type Reporter interface {
  OTELTraceExportError(err error)
  // PrometheusRequest is invoked every time the Prometheus exporter is invoked, for a given port and path
  PrometheusRequest(port, path string)
+ // DiscoverService is invoked every time a new service is discovered by the eBPF tracer
+ DiscoverService(service string)
+ // UndiscoverService is invoked every time a new service is removed from the discovered services by the eBPF tracer
+ UndiscoverService(service string)
 }
 
 // NoopReporter is a metrics Reporter that just does nothing
@@ -40,3 +44,5 @@ func (n NoopReporter) OTELMetricExportError(_ error) {}
 func (n NoopReporter) OTELTraceExport(_ int) {}
 func (n NoopReporter) OTELTraceExportError(_ error) {}
 func (n NoopReporter) PrometheusRequest(_, _ string) {}
+func (n NoopReporter) DiscoverService(_ string) {}
+func (n NoopReporter) UndiscoverService(_ string) {}

pkg/internal/imetrics/iprom.go

@@ -28,6 +28,7 @@ type PrometheusReporter struct {
  otelTraceExports prometheus.Counter
  otelTraceExportErrs *prometheus.CounterVec
  prometheusRequests *prometheus.CounterVec
+ discoveredServices *prometheus.GaugeVec
 }
 
 func NewPrometheusReporter(cfg *PrometheusConfig, manager *connector.PrometheusManager) *PrometheusReporter {
@@ -61,14 +62,19 @@ func NewPrometheusReporter(cfg *PrometheusConfig, manager *connector.PrometheusM
  Name: "prometheus_http_requests",
  Help: "requests towards the Prometheus Scrape endpoint",
  }, []string{"port", "path"}),
+ discoveredServices: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+ Name: "beyla_discovered_services",
+ Help: "discovered services by Beyla",
+ }, []string{"service"}),
  }
  manager.Register(cfg.Port, cfg.Path,
  pr.tracerFlushes,
  pr.otelMetricExports,
  pr.otelMetricExportErrs,
  pr.otelTraceExports,
  pr.otelTraceExportErrs,
- pr.prometheusRequests)
+ pr.prometheusRequests,
+ pr.discoveredServices)
 
  return pr
 }
@@ -100,3 +106,11 @@ func (p *PrometheusReporter) OTELTraceExportError(err error) {
 func (p *PrometheusReporter) PrometheusRequest(port, path string) {
  p.prometheusRequests.WithLabelValues(port, path).Inc()
 }
+
+func (p *PrometheusReporter) DiscoverService(service string) {
+ p.discoveredServices.WithLabelValues(service).Set(1)
+}
+
+func (p *PrometheusReporter) UndiscoverService(service string) {
+ p.discoveredServices.WithLabelValues(service).Set(0)
+}