metrics

Reusable wrapper around the OpenTelemetry Go metrics SDK with a Prometheus exporter, handling provider setup, resource attributes, and custom histogram buckets.

Features

• OpenTelemetry MeterProvider with Prometheus exporter
• Configurable service name, version, namespace, and environment
• Custom default histogram bucket boundaries
• Prometheus-compatible HTTP handler for /metrics
• Private Prometheus registry by default (avoids global pollution)
• Optional global MeterProvider registration
• Convenience attribute helpers (KeyValue, KeyInt, KeyFloat, KeyBool)

Key types

• Config -- provider configuration (service info, attributes, buckets, registry)
• Provider -- wraps MeterProvider with exporter and HTTP handler

Key functions

• Init(cfg) -- create and optionally register a global Provider
• NewProvider(cfg) -- create Provider without setting globals
• Provider.Meter() -- get an otelmetric.Meter for instrument creation
• Provider.HTTPHandler() -- Prometheus /metrics endpoint handler
• Provider.Shutdown(ctx) -- flush and shut down
• KeyValue, KeyInt, KeyFloat, KeyBool -- attribute helpers

Quick start

import (
    "net/http"
    "github.com/LingByte/ling-base/common/metrics"
)

provider, err := metrics.Init(metrics.Config{
    ServiceName:    "my-service",
    ServiceVersion: "1.0.0",
})
if err != nil {
    log.Fatal(err)
}
defer provider.Shutdown(ctx)

http.Handle("/metrics", provider.HTTPHandler())
go http.ListenAndServe(":9090", nil)

counter, _ := provider.Meter().Float64Counter("requests_total")
counter.Add(ctx, 1)

License

MIT