data-decoder

A data decoding util based on mapstructure package The main target of this package is to solve the problem when requiring nested values from viper. Viper doesn't process environment values as structured value, this causes problem when unmarshalling value to structs. Decoder requires value for nested struct fields particularly if it's not found from the data map required for it's parent struct. Environment values are used if the value is not defined in map-typed data in config files.

Example

Environments

LOGGING_FILE_PATH=decoder.log

Contents in yaml file

logging:
  level: debug

Logging Config Model

type LoggingConfig struct {
    Level string
    File struct{
        Path string
    }
}

Using viper

Code

v := viper.New()
cfgFilePath := "Config File Path"
v.SetConfigFile(cfgFilePath)
v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
v.AutomaticEnv()
v.MergeInConfig()
cfgModel := LoggingConfigModel{}
fmt.Println(v.Get("logging.file.path"))
v.UnmarshalKey("logging", &cfgModel)
fmt.Println(cfgModel)

Result

decoder.log
{debug {}}

Using data-decoder

Code

v := viper.New()
cfgFilePath := filepath.Join(os.Getenv("PROJECT_PATH"), "test", "fixture", "logging_config.yaml")
v.SetConfigFile(cfgFilePath)
v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
v.AutomaticEnv()
v.MergeInConfig()

d := decoder.NewDecoder(v)

cfgModel := LoggingConfigModel{}
fmt.Println(v.Get("logging.file.path"))
d.Decode("logging", &cfgModel)
fmt.Println(cfgModel)

Result

decoder.log
{debug {decoder.log}}