How to unmarshal config in my case

[KabudoWiseMan]

Hello, could you elaborate on how to unmarshal config in such case.

I have a config structure like so:

type Config struct {
	...
	TracingConfig   *HttpTracingConfig `mapstructure:"tracing"`
	...
}

type HttpTracingConfig struct {
	*HttpReporterConfig `validate:"required"`
        ...
}

type HttpReporterConfig struct {
	Url *string `mapstructure:"url" required:"true"`
}

And config file:

{
  ...
  "tracing": {
    "url": "http://zipkin-svc...",
    ...
  },
  ...
}

So I try to load config:

func Load(configPath string) (*Config, error) {
	viper.SetConfigFile(configPath)

	viper.AutomaticEnv()
	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))

	if err := viper.ReadInConfig(); err != nil {
		return nil, err
	}

	var config Config
	if err := viper.Unmarshal(&config); err != nil {
		return nil, err
	}

	return &config, validator.Struct(&config)
}

But unmarshaling doesn't work in such case. Why doesn't it recognise that key "tracing.url" should be placed as

HttpReporterConfig{
        Url: viper.Get("tracing.url")
}

And how do I fix that behaviour?

Thanks!

[sagikazarmark]

I believe this should do the trick:

type HttpTracingConfig struct {
	*HttpReporterConfig `validate:"required" mapstructure:",squash"`
        ...
}

Please check the mapstructure documentation for details.

[KabudoWiseMan]

Unfortunately squash doesn't work with pointers, so maybe there is some other trick?

More specific, I got an error: * HttpReporterConfig: unsupported type for squash: ptr