Using JSON-RPC with GraphQL modules in conjunction with Express, a private ethereum gas-free network can be created with support for truffle and metamask coneectivity.
When using a private ethereum network, should be placed behind a firewall with restricted access to the public facing internet.
Navigate to,
http://localhost:8545/graphql/ui
to view,
Learning GraphQL
(https://www.youtube.com/watch?v=l2rzT_Dp4T0)