95 lines
2.5 KiB
Go
95 lines
2.5 KiB
Go
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// Package tracing provides OpenTelemetry instrumentation for the API gateway.
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package tracing
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import (
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"context"
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"os"
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"time"
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"go.opentelemetry.io/otel"
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"go.opentelemetry.io/otel/attribute"
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"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
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"go.opentelemetry.io/otel/propagation"
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"go.opentelemetry.io/otel/sdk/resource"
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sdktrace "go.opentelemetry.io/otel/sdk/trace"
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semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
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)
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// Config holds tracing configuration.
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type Config struct {
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ServiceName string
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ServiceVersion string
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Environment string
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OTLPEndpoint string
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}
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// DefaultConfig returns configuration from environment variables.
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func DefaultConfig() Config {
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endpoint := os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT")
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if endpoint == "" {
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endpoint = "otel-collector.tracing.svc.cluster.local:4317"
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}
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return Config{
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ServiceName: getEnvOrDefault("OTEL_SERVICE_NAME", "api-gateway"),
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ServiceVersion: getEnvOrDefault("OTEL_SERVICE_VERSION", "1.0.0"),
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Environment: getEnvOrDefault("OTEL_ENVIRONMENT", "production"),
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OTLPEndpoint: endpoint,
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}
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}
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func getEnvOrDefault(key, defaultVal string) string {
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if v := os.Getenv(key); v != "" {
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return v
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}
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return defaultVal
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}
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// Init initializes the OpenTelemetry tracer provider.
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// Returns a shutdown function that should be called on application exit.
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func Init(ctx context.Context, cfg Config) (func(context.Context) error, error) {
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// Create OTLP exporter
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exporter, err := otlptracegrpc.New(ctx,
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otlptracegrpc.WithEndpoint(cfg.OTLPEndpoint),
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otlptracegrpc.WithInsecure(),
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otlptracegrpc.WithTimeout(5*time.Second),
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)
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if err != nil {
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return nil, err
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}
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// Create resource with service information
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res, err := resource.Merge(
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resource.Default(),
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resource.NewWithAttributes(
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semconv.SchemaURL,
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semconv.ServiceName(cfg.ServiceName),
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semconv.ServiceVersion(cfg.ServiceVersion),
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attribute.String("deployment.environment", cfg.Environment),
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),
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)
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if err != nil {
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return nil, err
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}
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// Create tracer provider with batch processor
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tp := sdktrace.NewTracerProvider(
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sdktrace.WithBatcher(exporter,
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sdktrace.WithBatchTimeout(5*time.Second),
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sdktrace.WithMaxExportBatchSize(512),
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),
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sdktrace.WithResource(res),
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sdktrace.WithSampler(sdktrace.AlwaysSample()),
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)
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// Set global tracer provider
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otel.SetTracerProvider(tp)
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// Set global propagator (W3C Trace Context + Baggage)
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otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
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propagation.TraceContext{},
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propagation.Baggage{},
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))
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return tp.Shutdown, nil
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}
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