Puppet 5 remains the software configuration management software of choice, especially for larger-scale configurations.
Here are some examples of current real-world use cases of Puppet:
- Twitter uses Puppet for what is currently one of the larger social networking infrastructures (https://blog.twitter.com/engineering/en_us/topics/infrastructure/2017/the-infrastructure-behind-twitter-scale.html). Facebook uses Opscode Chef, the competitive product in the software configuration management category.
- Uber uses Puppet for its standard configuration management (https://eng.uber.com/uchat/).
- Walmart is also a very large Puppet user (https://puppet.com/blog/how-walmart-scaled-puppet-55K-nodes-and-beyond).
Although there are newer products, such as Ansible and Salt, Puppet remains – I believe – the premier tool, especially for such larger infrastructures (10,000+ servers). It is worth mentioning that Ansible has also become very popular, possibly due to its shallower learning curve and adoption by Red Hat.
Dealing with this level of scale and complexity is non-trivial. With this book, Mastering Puppet 5, we want to put the know-how at your disposal to tackle your own large-scale challenges, at mastery level.
Version 5 of Puppet, which is the version covered by this book, was announced with considerable fanfare at last year's PuppetConf (2017) by the new CEO, Sanjay Mirchandani, as "Puppet's largest set of product innovations. Ever."
 In this book, we've gone through these new technologies, including Puppet Discovery, Puppet Tasks, and Puppet Pipelines, to give you the know-how you need to use Puppet 5 in the real world with confidence.
