struct.go

package config

import (
	"regexp"

	"gitlab.com/uafrica/go-utils/errors"
	"gitlab.com/uafrica/go-utils/logger"
	"gitlab.com/uafrica/go-utils/string_utils"
	"gitlab.com/uafrica/go-utils/struct_utils"
)

var (
	prefixStructs = map[string]interface{}{}
)

func LoadEnv(prefix string, configStructPtr interface{}) error {
	return Load(prefix, configStructPtr, string_utils.EnvironmentKeyReader())
}

func Load(prefix string, configStructPtr interface{}, keyReader string_utils.KeyReader) error {
	if !prefixRegex.MatchString(prefix) {
		return errors.Errorf("config(%s) invalid prefix", prefix)
	}

	//store before load in case it fails to be still part of docs
	prefixStructs[prefix] = configStructPtr

	//read os.Getenv() or other reader...
	nv := struct_utils.NamedValuesFromReader(prefix, keyReader)
	logger.Debugf("nv: %+v", nv)

	//parse into struct
	unused, err := struct_utils.UnmarshalNamedValues(nv, configStructPtr)
	if err != nil {
		return errors.Wrapf(err, "config(%s) cannot load", prefix)
	}
	if len(unused) > 0 {
		//we still use os.Getenv() elsewhere, so some variables may not be in the struct
		//e.g. AUDIT_QUEUE_URL is read from queues/sqs/producer which match config(prefix="AUDIT")
		//so we cannot yet fail here, which we should, because config setting not used is often
		//a reason for errors, when we try to configure something, then it does not work, and
		//we cannot figure out why, but the value we did set, might just be misspelled etc.
		//so, for now - do not fail here, just report the unused values
		logger.Warnf("Note unused env (might be used elsewhere) for config(%s): %+v", prefix, unused)
		//return errors.Errorf("config(%s): unknown %+v", prefix, unused)
	}

	if validator, ok := configStructPtr.(Validator); ok {
		if err := validator.Validate(); err != nil {
			return errors.Wrapf(err, "config(%s) is invalid", prefix)
		}
	}
	return nil
}

func LoadRedis(prefix string, configStructPtr interface{}) error {
	if !prefixRegex.MatchString(prefix) {
		return errors.Errorf("config(%s) invalid prefix", prefix)
	}

	//store before load in case it fails to be still part of docs
	prefixStructs[prefix] = configStructPtr

	//read os.Getenv()
	nv := struct_utils.NamedValuesFromEnv(prefix)

	//parse into struct
	unused, err := struct_utils.UnmarshalNamedValues(nv, configStructPtr)
	if err != nil {
		return errors.Wrapf(err, "config(%s) cannot load", prefix)