I am looking for JasperServer version 7.1 documentation regarding how to create a domain using the REST v2 API.
Nothing new with domains via REST between 7.1 and 7.2.
The structure of domains in REST is described here:
To create a domain via REST, you add the main domain "resource"
And then add the schema, security and translation files:
If you want to create the domain with all its parts in one pass, use the POST method with multipart requests described under https://community.jaspersoft.com/documentation/tibco-jasperreports-server-rest-api-reference/v720/resources-service#Creating_a_Resource This is what is happening with the JasperReports Server Java REST Client: https://github.com/sgwood63/jrs-rest-java-client#uploading-semanticlayerdatasource