Puppet is an open-source configuration management tool that runs on many Unix-like systems as well as on Microsoft Windows. It provides a declarative language and a Ruby-based domain-specific language (DSL) to describe the desired state of system resources, allowing administrators to define how systems should be configured and maintained.
Puppet stores configuration definitions in files known as Puppet manifests. To build a view of the current system, Puppet uses a utility called Facter to gather facts about the target system. The Puppet master compiles the manifests together with those facts into a system-specific catalog that lists resources and their dependencies. The agent on the target system applies the catalog, enforces the declared resource states, and reports the actions it took back to the server.
Using Puppet, teams can manage configuration consistently across many machines, automate repetitive tasks, and ensure that systems converge to the desired state. Manifests express resource types such as packages, services, files, and users, along with their properties and relationships. Puppet’s dependency model allows it to determine the correct order of operations so that changes are applied safely and predictably.
Puppet’s architecture supports both agent/master and agentless workflows, and it integrates with external tools for orchestration, reporting, and version control. Because manifests are plain text, they can be stored in code repositories, reviewed, and versioned, enabling infrastructure-as-code practices. When changes are committed and deployed, Puppet helps maintain system consistency and reduces configuration drift.
Administrators can extend Puppet through modules that package reusable manifests, templates, and custom types/providers. The ecosystem of modules makes it easier to adopt Puppet for common services and platforms while allowing for customization when needed. Logging and reporting features provide visibility into what changes were made and why, which supports troubleshooting and compliance auditing.
For teams managing both Unix-like and Windows environments, Puppet offers cross-platform resource abstractions so the same manifest can manage similar concerns across different operating systems. This reduces the need for platform-specific scripts and simplifies management at scale.
Overall, Puppet is a tool for defining, enforcing, and reporting on system configuration in a repeatable, automated manner, helping organizations implement reliable infrastructure-as-code practices.