Refactored initialization Beelzebub core with Builder Pattern (#14)

* Fixed deprecated function

* Coded builder pattern

* coded the first version builder

* coded rabbitmq into Builder.go

* Refactored builder, and configured director

* refactoring rabbitmq eventtracing

* Refactoring builder, managed close connections

* Fixed typos

Co-authored-by: mariocandela <mario.candela@nttdata.com>

builder/Builder.go

@@ -0,0 +1,125 @@
+package builder
+
+import (
+	"beelzebub/parser"
+	"beelzebub/protocols"
+	"beelzebub/tracer"
+	"errors"
+	"fmt"
+	amqp "github.com/rabbitmq/amqp091-go"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"os"
+)
+
+const RabbitmqQueueName = "event"
+
+type Builder struct {
+	beelzebubServicesConfiguration []parser.BeelzebubServiceConfiguration
+	traceStrategy                  tracer.Strategy
+	rabbitMQChannel                *amqp.Channel
+	rabbitMQConnection             *amqp.Connection
+	logsFile                       *os.File
+}
+
+func (b *Builder) setTraceStrategy(traceStrategy tracer.Strategy) {
+	b.traceStrategy = traceStrategy
+}
+
+func (b *Builder) buildLogger(configurations parser.Logging) error {
+	logsFile, err := os.OpenFile(configurations.LogsPath, os.O_APPEND|os.O_CREATE|os.O_RDWR, 0666)
+	if err != nil {
+		return err
+	}
+
+	log.SetOutput(io.MultiWriter(os.Stdout, logsFile))
+
+	log.SetFormatter(&log.JSONFormatter{
+		DisableTimestamp: configurations.LogDisableTimestamp,
+	})
+	log.SetReportCaller(configurations.DebugReportCaller)
+	if configurations.Debug {
+		log.SetLevel(log.DebugLevel)
+	} else {
+		log.SetLevel(log.InfoLevel)
+	}
+	b.logsFile = logsFile
+	return err
+}
+
+func (b *Builder) buildRabbitMQ(rabbitMQURI string) error {
+	rabbitMQConnection, err := amqp.Dial(rabbitMQURI)
+	if err != nil {
+		return err
+	}
+
+	b.rabbitMQChannel, err = rabbitMQConnection.Channel()
+	if err != nil {
+		return err
+	}
+
+	//creates a queue if it doesn't already exist, or ensures that an existing queue matches the same parameters.
+	if _, err = b.rabbitMQChannel.QueueDeclare(RabbitmqQueueName, false, false, false, false, nil); err != nil {
+		return err
+	}
+
+	b.rabbitMQConnection = rabbitMQConnection
+	return nil
+}
+
+func (b *Builder) Close() error {
+	if err := b.rabbitMQChannel.Close(); err != nil {
+		return err
+	}
+	if err := b.rabbitMQConnection.Close(); err != nil {
+		return err
+	}
+	if err := b.logsFile.Close(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (b *Builder) Run() error {
+	// Init Protocol strategies
+	secureShellStrategy := &protocols.SecureShellStrategy{}
+	hypertextTransferProtocolStrategy := &protocols.HypertextTransferProtocolStrategy{}
+	transmissionControlProtocolStrategy := &protocols.TransmissionControlProtocolStrategy{}
+
+	// Init Tracer strategies, and set the trace strategy default HTTP
+	protocolManager := protocols.InitProtocolManager(b.traceStrategy, hypertextTransferProtocolStrategy)
+
+	for _, beelzebubServiceConfiguration := range b.beelzebubServicesConfiguration {
+		switch beelzebubServiceConfiguration.Protocol {
+		case "http":
+			protocolManager.SetProtocolStrategy(hypertextTransferProtocolStrategy)
+			break
+		case "ssh":
+			protocolManager.SetProtocolStrategy(secureShellStrategy)
+			break
+		case "tcp":
+			protocolManager.SetProtocolStrategy(transmissionControlProtocolStrategy)
+			break
+		default:
+			log.Fatalf("Protocol %s not managed", beelzebubServiceConfiguration.Protocol)
+			continue
+		}
+
+		if err := protocolManager.InitService(beelzebubServiceConfiguration); err != nil {
+			return errors.New(fmt.Sprintf("Error during init protocol: %s, %s", beelzebubServiceConfiguration.Protocol, err.Error()))
+		}
+	}
+	return nil
+}
+
+func (b *Builder) build() *Builder {
+	return &Builder{
+		beelzebubServicesConfiguration: b.beelzebubServicesConfiguration,
+		traceStrategy:                  b.traceStrategy,
+	}
+}
+
+func NewBuilder() *Builder {
+	return &Builder{}
+}