|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + "os" |
| 7 | + "os/signal" |
| 8 | + "syscall" |
| 9 | + "time" |
| 10 | + |
| 11 | + "go.opentelemetry.io/collector/consumer" |
| 12 | + "go.opentelemetry.io/collector/pdata/pmetric" |
| 13 | + "go.uber.org/zap" |
| 14 | + |
| 15 | + "github.com/prometheus/client_golang/prometheus" |
| 16 | + "github.com/prometheus/client_golang/prometheus/promauto" |
| 17 | + dto "github.com/prometheus/client_model/go" |
| 18 | + |
| 19 | + "github.com/smartcontractkit/chainlink-common/pkg/promotel" |
| 20 | +) |
| 21 | + |
| 22 | +const testCounterMetricName = "test_counter_metric" |
| 23 | + |
| 24 | +func reportMetrics(reg prometheus.Registerer, logger *zap.Logger) { |
| 25 | + testCounter := promauto.With(reg).NewCounter(prometheus.CounterOpts{ |
| 26 | + Name: testCounterMetricName, |
| 27 | + ConstLabels: prometheus.Labels{ |
| 28 | + "app": "promotel-demo", |
| 29 | + }, |
| 30 | + }) |
| 31 | + for { |
| 32 | + testCounter.Inc() |
| 33 | + m := &dto.Metric{} |
| 34 | + _ = testCounter.Write(m) |
| 35 | + logger.Info("Reported Prometheus metric ", zap.Any("name", testCounterMetricName), zap.Any("value", m.GetCounter().GetValue())) |
| 36 | + time.Sleep(1 * time.Second) |
| 37 | + } |
| 38 | +} |
| 39 | + |
| 40 | +func gatherMetricsDirectly(reg prometheus.Gatherer, logger *zap.Logger) { |
| 41 | + for { |
| 42 | + mf, err := reg.Gather() |
| 43 | + if err != nil { |
| 44 | + fmt.Printf("Error gathering metrics: %v\n", err) |
| 45 | + } |
| 46 | + for _, metricFamily := range mf { |
| 47 | + if *metricFamily.Name == testCounterMetricName { |
| 48 | + for _, metric := range metricFamily.Metric { |
| 49 | + logger.Info("Received Prometheus metric ", zap.Any("name", testCounterMetricName), zap.Any("value", metric.Counter.GetValue())) |
| 50 | + } |
| 51 | + } |
| 52 | + } |
| 53 | + time.Sleep(1 * time.Second) |
| 54 | + } |
| 55 | +} |
| 56 | + |
| 57 | +func startExporter(ctx context.Context, logger *zap.Logger) promotel.MetricExporter { |
| 58 | + expConfig, err := promotel.NewExporterConfig(map[string]any{ |
| 59 | + "endpoint": "localhost:4317", |
| 60 | + "tls": map[string]any{ |
| 61 | + "insecure": true, |
| 62 | + }, |
| 63 | + }) |
| 64 | + if err != nil { |
| 65 | + logger.Fatal("Failed to create exporter config", zap.Error(err)) |
| 66 | + } |
| 67 | + // Sends metrics data in OTLP format to otel-collector endpoint |
| 68 | + exporter, err := promotel.NewMetricExporter(expConfig, logger) |
| 69 | + if err != nil { |
| 70 | + logger.Fatal("Failed to create metric exporter", zap.Error(err)) |
| 71 | + } |
| 72 | + err = exporter.Start(ctx) |
| 73 | + if err != nil { |
| 74 | + logger.Fatal("Failed to start exporter", zap.Error(err)) |
| 75 | + } |
| 76 | + return exporter |
| 77 | +} |
| 78 | + |
| 79 | +func startMetricReceiver(reg prometheus.Gatherer, logger *zap.Logger, next consumer.ConsumeMetricsFunc) promotel.Runnable { |
| 80 | + logger.Info("Starting promotel metric receiver") |
| 81 | + config, err := promotel.NewDefaultReceiverConfig() |
| 82 | + if err != nil { |
| 83 | + logger.Fatal("Failed to create config", zap.Error(err)) |
| 84 | + } |
| 85 | + |
| 86 | + // Gather metrics via promotel |
| 87 | + // MetricReceiver fetches metrics from pormetheus.Gatherer, then converts it to OTel format and writes formatted metrics to stdout |
| 88 | + receiver, err := promotel.NewMetricReceiver(config, reg, next, logger) |
| 89 | + |
| 90 | + if err != nil { |
| 91 | + logger.Fatal("Failed to create debug metric receiver", zap.Error(err)) |
| 92 | + } |
| 93 | + // Starts the promotel |
| 94 | + if err := receiver.Start(context.Background()); err != nil { |
| 95 | + logger.Fatal("Failed to start metric receiver", zap.Error(err)) |
| 96 | + } |
| 97 | + return receiver |
| 98 | +} |
| 99 | + |
| 100 | +func main() { |
| 101 | + logger, _ := zap.NewDevelopment() |
| 102 | + |
| 103 | + go reportMetrics(prometheus.DefaultRegisterer, logger) |
| 104 | + // Gather metrics directly from DefaultGatherer to verify that the metrics are being reported |
| 105 | + go gatherMetricsDirectly(prometheus.DefaultGatherer, logger) |
| 106 | + |
| 107 | + exporter := startExporter(context.Background(), logger) |
| 108 | + // Fetches metrics from in memory prometheus.Gatherer and converts to OTel format |
| 109 | + receiver := startMetricReceiver(prometheus.DefaultGatherer, logger, func(ctx context.Context, md pmetric.Metrics) error { |
| 110 | + // Logs the converted OTel metric |
| 111 | + logOtelMetric(md, testCounterMetricName, logger) |
| 112 | + // Exports the converted OTel metric |
| 113 | + return exporter.Consumer().ConsumeMetrics(ctx, md) |
| 114 | + }) |
| 115 | + |
| 116 | + // Wait for a signal to exit |
| 117 | + signalChan := make(chan os.Signal, 1) |
| 118 | + signal.Notify(signalChan, os.Interrupt, syscall.SIGTERM) |
| 119 | + |
| 120 | + // Block until a signal is received |
| 121 | + <-signalChan |
| 122 | + logger.Info("Exiting promotel") |
| 123 | + // Gracefully shuts down promotel |
| 124 | + if err := receiver.Close(); err != nil { |
| 125 | + logger.Fatal("Failed to close scraper", zap.Error(err)) |
| 126 | + } |
| 127 | + if err := exporter.Close(); err != nil { |
| 128 | + logger.Fatal("Failed to close exporter", zap.Error(err)) |
| 129 | + } |
| 130 | +} |
| 131 | + |
| 132 | +func logOtelMetric(md pmetric.Metrics, name string, logger *zap.Logger) { |
| 133 | + rms := md.ResourceMetrics() |
| 134 | + for i := 0; i < rms.Len(); i++ { |
| 135 | + rm := rms.At(i) |
| 136 | + ilms := rm.ScopeMetrics() |
| 137 | + for j := 0; j < ilms.Len(); j++ { |
| 138 | + ilm := ilms.At(j) |
| 139 | + metrics := ilm.Metrics() |
| 140 | + for k := 0; k < metrics.Len(); k++ { |
| 141 | + metric := metrics.At(k) |
| 142 | + if metric.Name() == name { |
| 143 | + logger.Info("Exporting OTel metric ", zap.Any("name", metric.Name()), zap.Any("value", metric.Sum().DataPoints().At(0).DoubleValue())) |
| 144 | + } |
| 145 | + } |
| 146 | + } |
| 147 | + } |
| 148 | +} |
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