Analyzing network environments for security flaws and assessing new service and infrastructure configurations in general are dangerous and error-prone when done in operational networks. Therefore, cloning such networks into a dedicated test environment is beneficial for comprehensive testing and analysis without impacting the operational network. To automate this reproduction of a network environment in a physical or virtualized testbed, several key features are required: (a) a suitable network model to describe network environments, (b) an automated acquisition process to instantiate this model for the respective network environment, and (c) an automated setup process to deploy the instance to the testbed.With this work, we present INSALATA, an automated and extensible framework to reproduce physical or virtualized network environments in network testbeds. INSALATA employs a modular approach for data acquisition and deployment, resolves interdependencies in the setup process, and supports just-in-time reproduction of network environments. INSALATA is open source and available on Github. To highlight its applicability, we present a real world case study utilizing INSALATA.