This tiny project is a way to configure Logrus Mate using Viper as the configuration source. It is meant to be used with the currently unreleased version of Logrus Mate (v1.0.0 doesn't have the configuration providers, only master branch does).

As Viper is very different to other configuration options, there is no way to mix it with e.g. HOCON. Basically, the assumption is that your project uses Viper and you don't want any other configuration system just for logging. If so, this library may come handy.

Here's a code snippet with usage example:

loggingConfig := viper.Sub("logging")
if loggingConfig != nil {
	mate, err := vipermate.NewMate(loggingConfig)
	if err != nil {
		logrus.WithError(err).Panic("Failed to process configuration")
	}
	if err = mate.Hijack(logrus.StandardLogger(), "main"); err != nil {
		logrus.WithError(err).Panic("Failed to configure main logger")
	}
}

Then, an example config (I use YAML, YMMV) could look like, e.g.:

logging:
  main:
    out:
      name: stdout
      options: {}
    level: debug
    formatter:
      name: text
      options:
        force-colors: true
        timestamp-format: "2006-01-02T15:04:05Z07:00"
        disable-timestamp: false
        full-timestamp: true
    hooks:
      # Let's say we want to set up an ELK hook
      logstash:
        protocol: tcp
        address: "elk.example.org:5959"
        name: "myapp"

Check out the source code for more details and information about the limitations. In particular, non-string slice functions are not implemented because Viper doesn't have anything like that.