oc-lib/tools/conf_loader.go

package tools

import (
	"strings"

	"cloud.o-forge.io/core/oc-lib/logs"
	"github.com/goraz/onion"
)

// GetConfLoader
// Get the configuration loader for the application
// Parameters:
// - AppName: string : the name of the application
// Returns:
// - *onion.Onion : the configuration loader
//  The configuration loader will load the configuration from the following sources:
//  - the environment variables with the prefix APPNAME_
//  - the file /etc/oc/appname.json
//  - the file ./appname.json
//  The configuration loader will merge the configuration from the different sources
//  The configuration loader will give priority to the environment variables
//  The configuration loader will give priority to the local file over the default file

func GetConfLoader() *onion.Onion {
	logger := logs.GetLogger()
	AppName := logs.GetAppName()
	EnvPrefix := strings.ToUpper(AppName[0:2]+AppName[3:]) + "_"
	defaultConfigFile := "/etc/oc/" + AppName[0:2] + ".json"
	localConfigFile := "./" + AppName[0:2] + ".json"
	var configFile string
	var o *onion.Onion
	l3 := onion.NewEnvLayerPrefix("_", EnvPrefix)
	l2, err := onion.NewFileLayer(localConfigFile, nil)
	if err == nil {
		logger.Info().Msg("Local config file found " + localConfigFile + ", overriding default file")
		configFile = localConfigFile
	}
	l1, err := onion.NewFileLayer(defaultConfigFile, nil)
	if err == nil {
		logger.Info().Msg("Config file found : " + defaultConfigFile)
		configFile = defaultConfigFile
	}
	if configFile == "" {
		logger.Info().Msg("No config file found, using env")
		o = onion.New(l3)
	} else if l1 != nil && l2 != nil {
		o = onion.New(l1, l2, l3)
	} else if l1 == nil {
		o = onion.New(l2, l3)
	} else if l2 == nil {
		o = onion.New(l1, l3)
	}
	return o
}