/
init_telemetry.go
175 lines (152 loc) · 5.68 KB
/
init_telemetry.go
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package telemetry
import (
"context"
"fmt"
"log"
"os"
"strings"
"time"
"github.com/turbot/go-kit/helpers"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
"go.opentelemetry.io/otel/metric/global"
"go.opentelemetry.io/otel/propagation"
controller "go.opentelemetry.io/otel/sdk/metric/controller/basic"
processor "go.opentelemetry.io/otel/sdk/metric/processor/basic"
"go.opentelemetry.io/otel/sdk/metric/selector/simple"
"go.opentelemetry.io/otel/sdk/resource"
sdktrace "go.opentelemetry.io/otel/sdk/trace"
semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
"google.golang.org/grpc"
)
func Init(serviceName string) (func(), error) {
ctx := context.Background()
// is telemetry enabled
telemetryEnvStr := strings.ToLower(os.Getenv(EnvOtelLevel))
tracingEnabled := helpers.StringSliceContains([]string{OtelAll, OtelTrace}, telemetryEnvStr)
metricsEnabled := helpers.StringSliceContains([]string{OtelAll, OtelMetrics}, telemetryEnvStr)
log.Printf("[TRACE] telemetry.Init service '%s', tracingEnabled: %v, metricsEnabled: %v", serviceName, tracingEnabled, metricsEnabled)
if !tracingEnabled && !metricsEnabled {
log.Printf("[TRACE] metrics and tracing disabled' - returning")
// return empty shutdown func
return func() {}, nil
}
// check whether a telemetry endpoint is configured
otelAgentAddr, endpointSet := os.LookupEnv(EnvOtelEndpoint)
if !endpointSet {
log.Printf("[TRACE] OTEL_EXPORTER_OTLP_ENDPOINT not set - defaulting to 'localhost:4317'")
otelAgentAddr = "localhost:4317"
}
log.Printf("[TRACE] endpoint: %s", otelAgentAddr)
var pusher *controller.Controller
var traceExp *otlptrace.Exporter
var tracerProvider *sdktrace.TracerProvider
var err error
if metricsEnabled {
pusher, err = initMetrics(ctx, otelAgentAddr)
if err != nil {
// return empty shutdown func
return nil, err
}
}
log.Printf("[TRACE] create client")
if tracingEnabled {
traceExp, tracerProvider, err = initTracing(ctx, otelAgentAddr, serviceName)
if err != nil {
return nil, err
}
}
shutdown := func() {
log.Printf("[TRACE] shutdown telemetry ")
cxt, cancel := context.WithTimeout(ctx, time.Second)
defer cancel()
if tracingEnabled {
// not sure why this is necessary - maybe because of batching?
tracerProvider.ForceFlush(context.Background())
if err := traceExp.Shutdown(cxt); err != nil {
log.Printf("[TRACE] error occurred during telemetry shutdown: %s", err.Error())
otel.Handle(err)
}
}
if metricsEnabled {
// pushes any last exports to the receiver
if err := pusher.Stop(cxt); err != nil {
log.Printf("[TRACE] error occurred during telemetry shutdown: %s", err.Error())
otel.Handle(err)
}
}
}
log.Printf("[TRACE] init telemetry end")
return shutdown, nil
}
func initMetrics(ctx context.Context, otelAgentAddr string) (*controller.Controller, error) {
log.Printf("[TRACE] telemetry.initMetrics")
metricClient := otlpmetricgrpc.NewClient(
otlpmetricgrpc.WithInsecure(),
otlpmetricgrpc.WithEndpoint(otelAgentAddr))
metricExp, err := otlpmetric.New(ctx, metricClient)
if err != nil {
log.Printf("[TRACE] initMetrics: failed to create the collector metric exporter: %s", err.Error())
return nil, fmt.Errorf("failed to initialise Open Telemetry: %s", err.Error())
}
pusher := controller.New(
processor.NewFactory(
simple.NewWithHistogramDistribution(),
metricExp,
),
controller.WithExporter(metricExp),
controller.WithCollectPeriod(2*time.Second),
)
global.SetMeterProvider(pusher)
if err := pusher.Start(ctx); err != nil {
log.Printf("[TRACE] initMetrics: failed to start metric pusher: %s", err.Error())
return nil, fmt.Errorf("failed to initialise Open Telemetry: %s", err.Error())
}
log.Printf("[TRACE] telemetry.initMetrics complete")
return pusher, nil
}
func initTracing(ctx context.Context, otelAgentAddr, serviceName string) (*otlptrace.Exporter, *sdktrace.TracerProvider, error) {
traceClient := otlptracegrpc.NewClient(
otlptracegrpc.WithInsecure(),
otlptracegrpc.WithEndpoint(otelAgentAddr),
otlptracegrpc.WithDialOption(grpc.WithBlock(), grpc.WithTimeout(5*time.Second)),
)
traceExp, err := otlptrace.New(ctx, traceClient)
if err != nil {
log.Printf("[TRACE] initTracing: error creating trace exporter: %v", err)
if strings.LastIndex(err.Error(), "context deadline exceeded") != -1 {
err = fmt.Errorf("timeout connecting to listener at %s", otelAgentAddr)
}
return nil, nil, fmt.Errorf("failed to initialise Open Telemetry: %s", err.Error())
}
log.Printf("[TRACE] got exporter")
res, err := resource.New(ctx,
resource.WithFromEnv(),
resource.WithProcess(),
resource.WithTelemetrySDK(),
resource.WithHost(),
resource.WithAttributes(
// the service name used to display traces in backends
semconv.ServiceNameKey.String(serviceName),
),
)
if err != nil {
log.Printf("[TRACE] initTracing: failed to create resource: %s", err.Error())
return nil, nil, fmt.Errorf("failed to initialise Open Telemetry: %s", err.Error())
}
log.Printf("[TRACE] got resource")
bsp := sdktrace.NewBatchSpanProcessor(traceExp)
tracerProvider := sdktrace.NewTracerProvider(
sdktrace.WithSampler(sdktrace.AlwaysSample()),
sdktrace.WithResource(res),
sdktrace.WithSpanProcessor(bsp),
)
log.Printf("[TRACE] got tracerProvider")
// set global propagator to tracecontext (the default is no-op).
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
otel.SetTracerProvider(tracerProvider)
return traceExp, tracerProvider, nil
}