go-prometheus

Go Prometheus is a package that allows you to integrate Prometheus, a popular open-source monitoring and alerting toolkit, into your golang applications. Prometheus is widely used for monitoring various aspects of software systems, including metrics, time series data, and alerting. By default this package aggregates metrics in memory, and it can also persist metrics to Redis when you need to share state across multiple processes.

Installation

Get Go Prometheus package on your project:

go get github.com/tech-djoin/go-prometheus

Usage

This packages provides a middleware using Echo which can be added as a global middleware or as a single route.

// in server file or anywhere middleware should be registered
e.Use(goprometheus.MetricCollector())

// in route file or anywhere route should be registered
router.Echo.GET("api/v1/posts", handler, goprometheus.MetricCollector())

Exporting Metrics

To exposes all metrics gathered by collectors, you need a route to access all metrics.

router.Echo.GET("/metrics", echo.WrapHandler(promhttp.Handler()))

Using Redis for Metric Storage

If you want to aggregate metrics across several application instances you can switch to the Redis-backed storage. Provide a Redis client (from github.com/redis/go-redis/v9) and install the backend before you start emitting metrics:

import (
	"log"

	"github.com/prometheus/client_golang/prometheus"
	goprometheus "github.com/tech-djoin/go-prometheus"
)

func init() {
	backend, err := goprometheus.NewRedisBackend(goprometheus.RedisBackendOptions{
		KeyPrefix: "app_metrics", // optional; defaults to no prefix
	})
	if err != nil {
		log.Fatalf("new redis backend: %v", err)
	}

	// Use Redis for recording metrics and register a collector to expose them.
	goprometheus.UseBackend(backend)
	prometheus.MustRegister(goprometheus.NewRedisCollectorFromBackend(backend))
}

When RedisBackendOptions.Client is omitted, the package reads its connection details from the following environment variables:

• GOPROM_REDIS_ADDR (optional) – full host:port value when you want to specify the address directly.
• GOPROM_REDIS_HOST and GOPROM_REDIS_PORT – used when GOPROM_REDIS_ADDR is not set (default 127.0.0.1:6379).
• GOPROM_REDIS_USERNAME and GOPROM_REDIS_PASSWORD – used when your Redis deployment requires credentials.

Metrics are stored in a set of Redis hashes keyed by the prefix you provide. The default latency histogram buckets (goprometheus.DefaultLatencyBuckets) are reused unless you override them in RedisBackendOptions.

License

This project is licensed under the MIT License - see the LICENSE.md file for details.

Contributors