Setting up Data Service HOWTO about gryphon

[garethdmm]

Yeah this is a blind-spot in the docs right now, just because it's a more advanced feature so it wasn't a priority to document for launch. I can get you started on these questions.

The GDS database is set up the same way as dashboards/trading. Make a new database, point your GDS_DB_CRED environment variable at it, and run gryphon-exec run_migrations --database gds

Foreman is a ruby gem, so it is usually installed with a command like gem install foreman.

There currently isn't a built-in entrypoint for GDS because it is a more complicated service than the strategy engine or other things accessible through gryphon-exec. GDS uses foreman to orchestrate multiple processes at once, and foreman requires a procfile in the current working directory. It was expected that users would want to edit their own procfile, so we left it without a simple entrypoint in the package.

emerald is an old name for GDS which still shows up in the code some places. They are the same thing.

It's actually fine to run runt.py on it's own for short to medium periods of time at once. You'll get orderbook data into redis that strategies can use, but the consumers won't be running so that data won't get into the GDS database.