Mnesia is not included in VerneMQ?

[Ugnius]

For a few days I am trying to develop custom script which includes mnesia module. I got stuck on the first step: mnesia is undefined in the VerneMQ environment.
VerneMQ is running in the docker container.
By starting erlang in container's terminal I can successfully start mnesia by writting: mnesia:create_schema([node()]).
The same function called in the VerneMQ hook is returned with error: "call to undefined function mnesia:create_schema".

I am not very familiar with erlang, and maybe there is something obvious and easily fixable? Thank you in advance.

P.S. I tried to write "mnesia" in .app.src under "applications" or "modules", but no luck.

[André Fatton]

Hi,

a VerneMQ build usually includes its own Erlang runtime, including some core libs. To add Mnesia, you have to add it to the release:

https://github.com/vernemq/vernemq/blob/db19fc99f552f2c11ae97d31408711028a85ac5d/rebar.config#L62

As you've noticed, the official binary packages do not include Mnesia. There wasn't real demand for that from customers so far. For future releases, I'm not against adding Mnesia, as it's actually not a bad idea to use it in plugins.

Hope this helps,

Best,

André