The scratch environment (http://core-functional.ci.folio.org/) is a shared environment for deploying and testing back-end modules. Back-end devs can use it in place of the local Okapi setups described in this document: https://dev.folio.org/guides/run-local-folio/, which eliminates a lot of the work of setting up a local development environment. No fiddling with virtualboxes, local host networks, or the Okapi module registration process necessary.
What is Rancher?
From the Rancher site: Rancher is an open source software platform that enables organizations to run and manage Docker and Kubernetes in production. With Rancher, organizations no longer have to build a container services platform from scratch using a distinct set of open source technologies. Rancher supplies the entire software stack needed to manage containers in production.
To put it another way, Rancher is a tool for deploying Docker containers to the scratch environment quickly and relatively painlessly. You can overwrite the stock docker container for a given module with your own and be testing it on the scratch environment in minutes.
More comprehensive information on Rancher: https://dev.folio.org/faqs/how-to-get-started-with-rancher/
Requirements:
Docker will need to be installed on your system, and you will need to set up a public docker repo in docker hub. Working with back-end modules also requires Maven and a recent version of the Java SE.
How to do it:
Clone the module you need to work on from github using the --recursive flag.
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