Provide documentation for ignoring "config file not found" error

[lucperkins]

Previously, this PR contained a solution to the problem pointed out in issue #1 (namely a ReadInConfigIfExists() function. But I think that the solution shown in the comments of #1 is probably a better approach, so I've chosen to document that approach instead.

cc @sagikazarmark

[CLAassistant]

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[sagikazarmark]

Thanks @lucperkins!

[fangpinsern]

Hi, I tried this solution and it does not seem to work. The error returned by err := viper.ReadInConfig() is an *fs.PathError error and not a viper.ConfigFileNotFoundError.

Though this is an old PR, google search on ignoring file not found leads me here. So just want to check if there is any new in built solutions to this issue?

Below is my code to initialize configurations

func InitializeConfig() {
	viper.SetConfigFile(".env")

	viper.AutomaticEnv()

	if err := viper.ReadInConfig(); err != nil {
		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
			panic(fmt.Errorf("fatal error config file: %w", err))
		}
	}
}

Thanks