Using package-level global variables

The apex and logrus packages in the earlier examples both used a package-level global variable. Sometimes, it's useful to structure your libraries to support both structs with a variety of methods and top-level functions so that you can use them directly without passing them around.

This recipe also demonstrates using sync.Once to ensure that the global logger will only be initialized once. It can also be bypassed by the Set method. The recipe only exports WithField and Debug, but one can imagine exporting every method attached to a log object.

Getting ready

Configure your environment according to these steps:

1. Refer to the Getting ready section of the Handling errors and the Error interface recipe.
2. Run the go get github.com/sirupsen/logrus command.

How to do it...

These steps cover writing and running your application:

1. From your terminal/console application, create thechapter4/global directory and navigate to it.
2. Copy tests from https://github.com/agtorre/go-cookbook...