This plugin provides cuttlefish and automatically updates the release configuration at runtime to utilize cuttlefish. There is no need to add schema files to the relx overlay, copy the cuttlefish escript or create a custom start script, it is all handled by the plugin provider.
Add the plugin to your top level rebar config:
{plugins, [rebar3_cuttlefish]}.
The cuttlefish release and tar providers need
$ rebar3 cuttlefish release
The plugin provider will tell relx to create the dirs share/schema in the release, copy the cuttlefish escript to bin/ and discover all schema files in the project apps and their dependencies.
Since cuttlefish uses sort order of the schema files by their name you may want to prepend a number to the schema file name, like 01-eleveldb.schema. While the plugin will automatically copy all schema files for you it will first check if there is already an overlay entry for each schema file. So if in overlay there is an entry {template, "schema/eleveldb.schema", "01-eleveldb.schema"} it will not make another copy.