But almost always the module or service that you work on relies on other services and datastores. boot2docker can help you pull down an entire stack to your workstation and not rely on connecting to an external network. You can essentially work on Airplane mode.
Or, you can architect your module/service to run the things it depends on in a self-contained manner and avoid creating a hard dependency on virtualization of Linux.
But almost always the module or service that you work on relies on other services and datastores. boot2docker can help you pull down an entire stack to your workstation and not rely on connecting to an external network. You can essentially work on Airplane mode.