promnatsfiber

promnatsfiber is a Go package designed to seamlessly integrate Prometheus metrics collection into applications using the Fiber web framework and NATS messaging system. It offers easy-to-use middleware for Fiber to collect HTTP metrics and a wrapper for NATS message handlers for message processing metrics. The package also includes system metrics collection using the gopsutil library.

Features

• Fiber Middleware for HTTP metrics collection.
• NATS Handler Wrapper for message processing metrics.
• System Metrics Collector for process-specific metrics (CPU, Memory, etc.).
• Easy integration with Prometheus for monitoring.

Exposed Metrics

promnatsfiber is designed to expose all the minimally required metrics for production use. The following metrics are exposed by the package:

HTTP Metrics

Metric Name	Metric Type	Description
http_requests_total	Counter	Total number of HTTP requests processed by the Fiber app.
http_request_duration_seconds	Histogram	Total duration of HTTP requests processed by the Fiber app.
http_requests_in_progress_total	Gauge	Total number of HTTP requests currently being processed by the Fiber app.

NATS Metrics

Metric Name	Metric Type	Description
nats_messages_processed_total	Counter	Total number of NATS messages processed by the Fiber app.
nats_message_processing_duration_seconds	Histogram	Total duration of NATS messages processed by the Fiber app.
nats_publishing_messages_total	Counter	Total number of NATS messages published by the Fiber app.
nats_publishing_message_duration_seconds	Histogram	Total duration of NATS messages published by the Fiber app.

System Metrics

Metric Name	Metric Type	Description
system_cput_usage_percent	Constant Gauge	Current CPU usage percentage.
system_memory_usage_bytes	Constant Gauge	Current memory usage in bytes.
system_memory_total_bytes	Constant Gauge	Total memory in bytes.
system_gc_stats	Constant Gauge	Garbage collection statistics.
system_go_routine_count	Constant Gauge	Current number of Go routines.

Installation

To install promnatsfiber, you need to have Go installed on your machine. You can then use the following command:

go get github.com/todesdev/promnatsfiber

Usage

Here's a quick example to get you started:

package main

import (
	"github.com/gofiber/fiber/v2"
	"github.com/nats-io/nats.go"
	"github.com/todesdev/promnatsfiber"
	"github.com/todesdev/promnatsfiber/middleware"
	"log"
)

func main() {
	// Create new Fiber instance
	app := fiber.New()

	// Connect to NATS
	natsConnection := connectToNats()

	// Initialize the metrics collectors, register Fiber middleware, and register the metrics endpoint
	promnatsfiber.New(&promnatsfiber.Config{
		FiberApp:        app,
		ServiceName:     "my-service",
		MetricsEndpoint: "/metrics",
	})

	// Subscribe to NATS messages
	go subscribeToMessages(natsConnection)

	// Start the Fiber app
	log.Fatal(app.Listen(":3000"))
}

func connectToNats() *nats.Conn {
	nc, err := nats.Connect(nats.DefaultURL)
	if err != nil {
		log.Fatal(err)
	}

	return nc
}

// Example of wrapping a NATS message handler with the promnatsfiber middleware
// NATS metrics are collected automatically by using the middleware
func subscribeToMessages(nc *nats.Conn) {
	sub, err := nc.Subscribe("messages", middleware.WrapProcessMessage(messageHandler))
	if err != nil {
		log.Fatal(err)
	}

	defer func(sub *nats.Subscription) {
		err := sub.Unsubscribe()
		if err != nil {
			log.Fatal(err)
		}
	}(sub)
}

func messageHandler(msg *nats.Msg) {
	log.Printf("Received a message: %s\n", string(msg.Data))
}

For detailed usage and more examples, refer to examples:

• Fiber and Simple NATS subscription
• Fiber and Simple NATS publishing
• Fiber and JetStream queue subscription
• Fiber and JetStream publishing

Special Acknowledgements

This project was inspired by the fiberprometheus package. We extend our gratitude to the authors and contributors of fiberprometheus for their invaluable work, which guided the development of promnatsfiber.

Acknowledgements

This project makes use of several open-source libraries:

• Fiber
• Prometheus Go client library
• NATS - Go Client
• gopsutil

We are grateful to these authors for their contributions to the open-source community.

License

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