Initial working poc for publishing to rabbitmq

lib/service/rabbitmq.go

@@ -0,0 +1,115 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/getAlby/lndhub.go/common"
+	"github.com/getAlby/lndhub.go/db/models"
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+func (svc *LndhubService) StartRabbitMqPublisher(ctx context.Context) error {
+	conn, err := amqp.Dial(svc.Config.RabbitMQUri)
+	if err != nil {
+		return err
+	}
+	svc.RabbitMqConn = conn
+	ch, err := conn.Channel()
+	if err != nil {
+		return err
+	}
+	defer ch.Close()
+
+	err = ch.ExchangeDeclare(
+		//TODO: review exchange config
+		svc.Config.RabbitMQInvoiceExchange,
+		"topic", // type
+		true,    // durable
+		false,   // auto-deleted
+		false,   // internal
+		false,   // no-wait
+		nil,     // arguments
+	)
+	if err != nil {
+		return err
+	}
+
+	svc.Logger.Infof("Starting rabbitmq publisher")
+	incomingInvoices := make(chan models.Invoice)
+	outgoingInvoices := make(chan models.Invoice)
+	_, err = svc.InvoicePubSub.Subscribe(common.InvoiceTypeIncoming, incomingInvoices)
+	if err != nil {
+		svc.Logger.Error(err.Error())
+	}
+	_, err = svc.InvoicePubSub.Subscribe(common.InvoiceTypeOutgoing, outgoingInvoices)
+	if err != nil {
+		svc.Logger.Error(err.Error())
+	}
+	for {
+		select {
+		case <-ctx.Done():
+			return fmt.Errorf("context canceled")
+		case incoming := <-incomingInvoices:
+			svc.publishInvoice(ctx, incoming, ch)
+		case outgoing := <-outgoingInvoices:
+			svc.publishInvoice(ctx, outgoing, ch)
+		}
+	}
+}
+
+func (svc *LndhubService) publishInvoice(ctx context.Context, invoice models.Invoice, ch *amqp.Channel) {
+	key := fmt.Sprintf("%s.%s.invoice", invoice.Type, invoice.State)
+
+	//Look up the user's login to add it to the invoice
+	user, err := svc.FindUser(context.Background(), invoice.UserID)
+	if err != nil {
+		svc.Logger.Error(err)
+		return
+	}
+
+	payload := new(bytes.Buffer)
+	err = json.NewEncoder(payload).Encode(WebhookInvoicePayload{
+		ID:                       invoice.ID,
+		Type:                     invoice.Type,
+		UserLogin:                user.Login,
+		Amount:                   invoice.Amount,
+		Fee:                      invoice.Fee,
+		Memo:                     invoice.Memo,
+		DescriptionHash:          invoice.DescriptionHash,
+		PaymentRequest:           invoice.PaymentRequest,
+		DestinationPubkeyHex:     invoice.DestinationPubkeyHex,
+		DestinationCustomRecords: invoice.DestinationCustomRecords,
+		RHash:                    invoice.RHash,
+		Preimage:                 invoice.Preimage,
+		Keysend:                  invoice.Keysend,
+		State:                    invoice.State,
+		ErrorMessage:             invoice.ErrorMessage,
+		CreatedAt:                invoice.CreatedAt,
+		ExpiresAt:                invoice.ExpiresAt.Time,
+		UpdatedAt:                invoice.UpdatedAt.Time,
+		SettledAt:                invoice.SettledAt.Time,
+	})
+	if err != nil {
+		svc.Logger.Error(err)
+		return
+	}
+
+	err = ch.PublishWithContext(ctx,
+		svc.Config.RabbitMQInvoiceExchange,
+		key,
+		false,
+		false,
+		amqp.Publishing{
+			ContentType: "application/json",
+			Body:        payload.Bytes(),
+		},
+	)
+	if err != nil {
+		svc.Logger.Error(err)
+		return
+	}
+	svc.Logger.Debugf("Succesfully published %s", payload.String())
+}