Distributed Mnesia

[nisbus]

Makes mnesia replicate all data between nodes.

• Adds Nodefinder as a dependency.

On startup, if there are other nodes in the cluster the mnesia storage will replicate from the other nodes.
Multiple nodes will then have all records synced between them.

Testing:

• Create directories for two mnesia storage locations for example: one and two
• Enable mnesia storage backend in erldns.config.

{erldns
      {storage, [
             {type, erldns_storage_mnesia},
             {dir, "./one"}
            ]
      }
}
{mnesia,
[
{dir, "./one"}
]},

Run the first node:

rebar3 shell --sname one --setcookie dns

• Edit erldns.config to run on a different port (e.g. 8054)
• Change the storage location for mnesia to the second location you created ("./two").
• Empty the priv/example.zone.json to only contain "[]"

Run the second node:

rebar3 shell --sname two --setcookie dns

Test that both nodes respond with the first node zones.

dig @127.0.0.1 -p 8053 example.com
dig @127.0.0.1 -p 8054 example.com