Use config package to handle all controller configurations

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

config/config.go

+package config
+
+import (
+	"os"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+)
+
+const (
+	defaultTimeOutDuration10minutes = time.Minute * 10
+	basePNDUUIDKey                  = "basePNDUUID"
+	baseSouthBoundTypeKey           = "baseSouthBoundType"
+	baseSouthBoundUUIDKey           = "baseSouthBoundUUID"
+	changeTimeoutKey                = "GOSDN_CHANGE_TIMEOUT"
+)
+
+// BasePndUUID is an uuid for the base PND
+var BasePndUUID uuid.UUID
+
+// BaseSouthBoundType is the type of the base SBI
+var BaseSouthBoundType int32
+
+// BaseSouthBoundUUID is an uuid for the base SBI
+var BaseSouthBoundUUID uuid.UUID
+
+// ChangeTimeout is the default timeout for a change
+var ChangeTimeout time.Duration
+
+// LogLevel ist the default log level
+var LogLevel logrus.Level
+
+// Init gets called on module import
+func Init() {
+	InitializeConfig()
+}
+
+// InitializeConfig loads the configuration
+func InitializeConfig() error {
+	var err error
+
+	basePNDUUIDFromViper, err := getUUIDFromViper(basePNDUUIDKey)
+	if err != nil {
+		return err
+	}
+
+	BasePndUUID = basePNDUUIDFromViper
+
+	baseSouthBoundUUIDFromViper, err := getUUIDFromViper(baseSouthBoundUUIDKey)
+	if err != nil {
+		return err
+	}
+
+	BaseSouthBoundUUID = baseSouthBoundUUIDFromViper
+
+	BaseSouthBoundType = viper.GetInt32(baseSouthBoundTypeKey)
+	if BaseSouthBoundType != 0 {
+		viper.Set(baseSouthBoundTypeKey, 0)
+		viper.WriteConfig()
+	}
+
+	err = setChangeTimeout()
+	if err != nil {
+		return err
+	}
+
+	setLogLevel()
+
+	return nil
+}
+
+func getUUIDFromViper(viperKey string) (uuid.UUID, error) {
+	UUIDAsString := viper.GetString(viperKey)
+	if UUIDAsString == "" {
+		newUUID := uuid.New()
+		viper.Set(viperKey, newUUID.String())
+		viper.WriteConfig()
+
+		return newUUID, nil
+	}
+
+	parsedUUID, err := uuid.Parse(UUIDAsString)
+	if err != nil {
+		return uuid.Nil, err
+	}
+
+	return parsedUUID, nil
+}
+
+func setChangeTimeout() error {
+	e := os.Getenv(changeTimeoutKey)
+	if e != "" {
+		changeTimeout, err := time.ParseDuration(e)
+		if err != nil {
+			log.Fatal(err)
+		}
+		ChangeTimeout = changeTimeout
+	} else {
+		ChangeTimeout = time.Minute * 10
+	}
+
+	return nil
+}
+
+func setLogLevel() {
+	if os.Getenv("GOSDN_LOG") == "nolog" {
+		LogLevel = logrus.PanicLevel
+	} else {
+		LogLevel = logrus.InfoLevel
+	}
+}