Publisher plugin implementation

2025-04-29 15:45:26 +05:30
parent e65ee8d644
commit ae98cc992f
4 changed files with 218 additions and 0 deletions
--- a/pkg/plugin/implementation/publisher/publisher.go
+++ b/pkg/plugin/implementation/publisher/publisher.go
@@ -0,0 +1,119 @@
+package publisher
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+
+	"github.com/beckn/beckn-onix/pkg/log"
+	"github.com/beckn/beckn-onix/pkg/model"
+	"github.com/rabbitmq/amqp091-go"
+)
+
+// Config holds the configuration required to establish a connection with RabbitMQ.
+type Config struct {
+	Addr       string
+	Exchange   string
+	RoutingKey string
+	Durable    bool
+	UseTLS     bool
+}
+
+// Publisher manages the RabbitMQ connection and channel to publish messages.
+type Publisher struct {
+	Conn    *amqp091.Connection
+	Channel *amqp091.Channel
+	Config  *Config
+}
+
+// Error variables representing different failure scenarios.
+var (
+	ErrEmptyConfig       = errors.New("empty config")
+	ErrAddrMissing       = errors.New("missing required field 'Addr'")
+	ErrExchangeMissing   = errors.New("missing required field 'Exchange'")
+	ErrCredentialMissing = errors.New("missing RabbitMQ credentials in environment")
+	ErrConnectionFailed  = errors.New("failed to connect to RabbitMQ")
+	ErrChannelFailed     = errors.New("failed to open channel")
+	ErrExchangeDeclare   = errors.New("failed to declare exchange")
+)
+
+// Validate checks whether the provided Config is valid for connecting to RabbitMQ.
+func Validate(cfg *Config) error {
+	if cfg == nil {
+		return model.NewBadReqErr(fmt.Errorf("config is nil"))
+	}
+	if strings.TrimSpace(cfg.Addr) == "" {
+		return model.NewBadReqErr(fmt.Errorf("missing config.Addr"))
+	}
+	if strings.TrimSpace(cfg.Exchange) == "" {
+		return model.NewBadReqErr(fmt.Errorf("missing config.Exchange"))
+	}
+	return nil
+}
+
+// GetConnURL constructs the RabbitMQ connection URL using the config and environment credentials.
+func GetConnURL(cfg *Config) (string, error) {
+	user := os.Getenv("RABBITMQ_USERNAME")
+	pass := os.Getenv("RABBITMQ_PASSWORD")
+	if user == "" || pass == "" {
+		return "", model.NewBadReqErr(fmt.Errorf("missing RabbitMQ credentials in environment"))
+	}
+
+	parts := strings.SplitN(cfg.Addr, "/", 2)
+	hostPort := parts[0]
+	vhost := "/"
+	if len(parts) > 1 {
+		vhost = parts[1]
+	}
+
+	if !strings.Contains(hostPort, ":") {
+		if cfg.UseTLS {
+			hostPort += ":5671"
+		} else {
+			hostPort += ":5672"
+		}
+	}
+
+	encodedUser := url.QueryEscape(user)
+	encodedPass := url.QueryEscape(pass)
+	encodedVHost := url.QueryEscape(vhost)
+	protocol := "amqp"
+	if cfg.UseTLS {
+		protocol = "amqps"
+	}
+
+	connURL := fmt.Sprintf("%s://%s:%s@%s/%s", protocol, encodedUser, encodedPass, hostPort, encodedVHost)
+	log.Debugf(context.Background(), "Generated RabbitMQ connection URL: %s", connURL)
+	return connURL, nil
+}
+
+// Publish sends a message to the configured RabbitMQ exchange with the specified routing key.
+// If routingKey is empty, the default routing key from Config is used.
+func (p *Publisher) Publish(ctx context.Context, routingKey string, msg []byte) error {
+	if routingKey == "" {
+		routingKey = p.Config.RoutingKey
+	}
+	log.Debugf(ctx, "Attempting to publish message. Exchange: %s, RoutingKey: %s", p.Config.Exchange, routingKey)
+	err := p.Channel.PublishWithContext(
+		ctx,
+		p.Config.Exchange,
+		routingKey,
+		false,
+		false,
+		amqp091.Publishing{
+			ContentType: "application/json",
+			Body:        msg,
+		},
+	)
+
+	if err != nil {
+		log.Errorf(ctx, err, "Publish failed for Exchange: %s, RoutingKey: %s", p.Config.Exchange, routingKey)
+		return model.NewBadReqErr(fmt.Errorf("publish message failed: %w", err))
+	}
+
+	log.Infof(ctx, "Message published successfully to Exchange: %s, RoutingKey: %s", p.Config.Exchange, routingKey)
+	return nil
+}