How to resolve toml naming incompatibility with env

[ericedem]

Hey, thanks for the great library!

My question revolves around a legacy app that uses .toml where I want to also be able to override defaults with environment variables. For example, I may have a toml file like this:

[feature]
  is_enabled = true

And then in golang I would do something like this:

isEnabled := viper.GetBool("feature.is_enabled")

What I'd like to do is add an environment variable override using viper.AutomaticEnv() or viper.BindEnv("feature.is_enabled"). However it looks like what ends up happening in this case is that "feature.is_enabled" will be converted to an environment variable key "FEATURE.IS_ENABLED" which is a malformed environment key; at least in bash.

To work around this, I've manually added overrides like so:

viper.BindEnv("feature.is_enabled", "FEATURE_IS_ENABLED")

But what I'd prefer to do is use viper.AutomaticEnv() so that I can override as I please without having to make new code changes or forgetting to bind some parameter. Does anyone have any recommendations here? I was thinking about opening up an issue to find and replace . characters in viper.BindEnv() but figured asking a question first is better in case someone had an idea.

Thanks!

[sagikazarmark]

Take a look at the SetEnvKeyReplacer function.

[ericedem]

This is perfect thank you. I can do:

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