Subnetworks
Want to get started with subnetworks? See how to easily simulate a networking failure here
A service started inside a Kurtosis enclave will by default be able to communicate with all other services inside the same enclave. To change that behavior, Kurtosis exposes the concept of subnetworks.
A subnetwork is a way to group together an arbitrary number of services from the same enclave. It is very lightweight and it can be instantiated by "tagging" each service with a subnetwork name (see add_service and update_service). A service added to an enclave without a subnetwork specified is added to the default subnetwork (called default).
All services with the same "subnetwork tag" will belong to the same subnetwork, and networking can then be configured accross subnetworks. All services in the same subnetwork (including the default one) will always be able to communicate.
The connection configuration between two subnetworks inherits a default connection defined in Kurtosis. It is set to allow all communications when the enclave starts but it can be changed using set_connection.
To have fine grained control, the connection between two specific subnetworks can be overridden also using the same set_connection. The override can be removed using remove_connection.
This functionaility is only available for Kurtosis running on Docker. Kurtosis running on Kubernetes cannot use subnetworks yet, and instructions requiring it will throw an error.
This functionality must be enabled manually per enclave using the CLI. When running Starlark scripts or packages using this feature, add the --with-subnetworks optional flag.