desiredstate

Desiredstate is a modeling approach in which the intended configuration and behavior of a system are described explicitly, as opposed to the steps used to achieve them. The term is used in configuration management, infrastructure as code, and deployment to express the end condition that a system should reach. It is commonly described as a “desired state” or as “Desired State Configuration” (DSC) in specific tools, and sometimes written as a single word in code or project names.

In a desired-state model, administrators declare the target state—such as installed packages, running services, network rules, and file permissions—and a management engine enforces it. The engine compares the actual state to the declared state, detects drift, and issues changes to reconcile the two. This embodies the declarative paradigm, as opposed to imperative scripts that specify how to reach a target outcome.

Examples include Windows Desired State Configuration (DSC) and configuration tools such as Puppet, Chef, and Ansible, which rely on declarative manifests. In modern platforms like Kubernetes, controllers continuously reconcile the observed cluster state with the user-defined specification, ensuring the live environment conforms to the desired state. Infrastructure as code tools such as Terraform maintain a representation of the intended resources and apply changes to reach that state.

Advantages of desired-state management include repeatability, predictability, easier auditing, and reduced drift between environments. Challenges include accurately expressing complex configurations, handling external changes, ensuring convergence, and dealing with partial failures or conflicting constraints. Security, access control, and performance considerations are also important in large-scale deployments.