Can I tell viper.Unmarshal to take environment variables into account?

[aeneasr]

This is my viper config:

    if cfgFile != "" {
        // enable ability to specify config file via flag
        viper.SetConfigFile(cfgFile)
    }

    path := absPathify("$HOME")
    if _, err := os.Stat(filepath.Join(path, ".hydra.yml")); err != nil {
        _, _ = os.Create(filepath.Join(path, ".hydra.yml"))
    }

    viper.SetConfigType("yaml")
    viper.SetConfigName(".hydra") // name of config file (without extension)
    viper.AddConfigPath("$HOME")  // adding home directory as first search path
    viper.AutomaticEnv()          // read in environment variables that match

    // If a config file is found, read it in.
    if err := viper.ReadInConfig(); err != nil {
        fmt.Printf(`Config file not found because "%s"`, err)
        fmt.Println("")
    }

I also have a bunch of environment varibales, like CLIENT_ID or DATABASE_URL. Right now I'm setting those via:

    if databaseURL, ok := viper.Get("DATABASE_URL").(string); ok {
        c.DatabaseURL = databaseURL
    }

Is it possible to tell viper.Unmarshal to use the environment variables in addition to the config file?

[aeneasr]

yes, i need to use BindEnv and write the keys upper case in mapstructure:...

[postcert]

I was able to get it working without BindEnv or setting the mapstructure tags uppercase.
Though I am calling ReadInConfig prior to AutomaticEnv. Then after unmarshaling into the config struct of course.

Give it a try, repeated BindEnv calls sounds very tedious.

[aeneasr]

That worked for me too!

[Ehekatl]

@postcert did't get it work here, can u give some sample code ? many thx

[Ehekatl]

I found that unmarshal env variable only work when the key is also in config file...not sure if this is bug

[postcert]

Yes, it only works when already present in the config file. Still discovering these edge cases.

[astoliarov]

Hi! Is it working?

[sagikazarmark]

Please see and follow the issue above. ☝️