micro/config/configfiles.go

112 lines
2.8 KiB
Go

package config
import (
"fmt"
"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, executableErr := os.Executable()
if executableErr != nil {
executablePath = os.Args[0]
}
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))
}
homeDir := "."
if usr, userErr := user.Current(); userErr == nil {
homeDir = usr.HomeDir
}
fileNames = append(fileNames, filepath.Join(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 resolveConfigFile[T any](config T, configFile string) (string, error) {
if configFile != "" {
if !util.FileExists(configFile) {
return "", fmt.Errorf("given configuration file %s cannot be found", configFile)
}
return configFile, nil
}
appName := getAppNameFromConfig(config)
if appName == "" {
return "", nil
}
return GetConfigurationFile(appName), nil
}
func getAppNameFromConfig[T any](config T) string {
method := reflect.ValueOf(config).MethodByName("AppName")
if !method.IsValid() {
return ""
}
results := method.Call(nil)
if len(results) == 0 {
return ""
}
return results[0].String()
}
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 fmt.Errorf("type: %s.%s is not a struct pointer", genericType.PkgPath(), genericType.Name())
}
defaults.Set(config)
resolvedConfigFile, err := resolveConfigFile(config, configFile)
if err != nil {
return err
}
if resolvedConfigFile == "" {
return nil
}
ymldata, err := os.ReadFile(resolvedConfigFile)
if err != nil {
return fmt.Errorf("cannot read configuration file %s: %w", resolvedConfigFile, err)
}
err = yaml.Unmarshal(ymldata, config)
if err != nil {
return fmt.Errorf("error unmarshalling configuration data: %w", err)
}
return nil
}