home_data/gatherer/piper.go

package main

import (
	"github.com/influxdata/influxdb-client-go/v2/api/write"
	amqp "github.com/rabbitmq/amqp091-go"
)

func create_and_connect_to_queue(ch *amqp.Channel, name string, routing_key string) <-chan amqp.Delivery {
	q, err := ch.QueueDeclare(
		name,  // name
		false, // durable
		false, // delete when unused
		true,  // exclusive
		false, // no-wait
		nil,   // arguments
	)
	failOnError(err, "Failed to declare a queue")

	err = ch.QueueBind(
		q.Name,      // queue name
		routing_key, // routing key
		"amq.topic", // exchange
		false,
		nil,
	)
	failOnError(err, "Failed to bind a queue")

	msgs, err := ch.Consume(
		q.Name, // queue
		"",     // consumer
		true,   // auto ack
		false,  // exclusive
		false,  // no local
		false,  // no wait
		nil,    // args
	)
	failOnError(err, "Failed to register a consumer")

	return msgs
}

type Piper struct {
	influx   *InfluxWriter
	delivery <-chan amqp.Delivery
}

func (p *Piper) Init(writer *InfluxWriter, amqp AMQPConnection, queue_name string, routing_key string) {
	// Create a new client using an InfluxDB server base URL and an authentication token
	p.influx = writer
	p.delivery, _ = amqp.ConnectToQueue(queue_name, routing_key)

	notify := amqp.NotifyError()
	go func() {
		for _ = range notify {
			p.delivery, _ = amqp.ConnectToQueue(queue_name, routing_key)
			println("Reconnected to queue")
		}
	}()
}

func (p *Piper) RunPipe(
	conversion func(amqp.Delivery) ([]*write.Point, error),
) {
	// Create point using fluent style
	for msg := range p.delivery {
		points, _ := conversion(msg)
		// Write data
		for _, point := range points {
			p.influx.Write(point)
		}
	}

}