micro/config/configfiles.go

88 lines
2.4 KiB
Go

package config
import (
"errors"
"fmt"
"io/ioutil"
"os"
"os/user"
"path/filepath"
"reflect"
"github.com/creasty/defaults"
"gopkg.in/yaml.v3"
"scm.yoorie.de/go-lib/util"
)
func GetConfigurationFiles(appName string) []string {
// First checking local config
executablePath, _ := os.Executable()
fname := filepath.Base(executablePath)
fext := filepath.Ext(executablePath)
fdir := filepath.Dir(executablePath)
fnameWoExt := fname[0 : len(fname)-len(fext)]
ymlExts := [2]string{".yml", ".yaml"}
fileNames := make([]string, 0, 4)
for _, ext := range ymlExts {
fileNames = append(fileNames, filepath.Join(fdir, fnameWoExt+ext))
}
usr, _ := user.Current()
fileNames = append(fileNames, filepath.Join(usr.HomeDir, "."+appName, "config"))
// Check for global config
fileNames = append(fileNames, util.GetGlobalConfigurationFile(appName, "config"))
return fileNames
}
func GetConfigurationFile(appName string) string {
// First checking local config
files := GetConfigurationFiles(appName)
for _, localConfigFile := range files {
if util.FileExists(localConfigFile) {
return localConfigFile
}
}
return ""
}
func LoadConfiguration[T any](config T) error {
return LoadConfigurationFromFile(config, "")
}
func IsStructPointer[T any](config T) bool {
value := reflect.ValueOf(config)
return value.Type().Kind() == reflect.Pointer && reflect.Indirect(value).Type().Kind() == reflect.Struct
}
func LoadConfigurationFromFile[T any](config T, configFile string) error {
if !IsStructPointer(config) {
genericType := reflect.TypeOf(config)
return errors.New(fmt.Sprintf("Type: %s.%s is not a struct pointer", genericType.PkgPath(), genericType.Name()))
}
defaults.Set(config)
if configFile != "" {
if !util.FileExists(configFile) {
return errors.New(fmt.Sprintf("given configuration file %s cannot be found", configFile))
}
} else {
if method := reflect.ValueOf(config).MethodByName("appName"); !method.IsNil() {
result := method.String()
if result != "" {
configFile = GetConfigurationFile(result)
}
}
}
if configFile == "" {
return nil
}
ymldata, err := ioutil.ReadFile(configFile)
if err != nil {
return errors.New(fmt.Sprintf("cannot read configuration file %s. %v", configFile, err))
}
err = yaml.Unmarshal(ymldata, config)
if err != nil {
return errors.New(fmt.Sprintf("error unmarshalling configuration data: %v", err))
}
return nil
}