Add `ping` to Docker image

What does “if the worker is running” mean? Unless it means that the server has loaded all predicates from bulk export and is ready to run queries, I still need to use ping to do what I want.

I have a separate container that spins up, does some operations, and creates the RDF file and uses the bulk loader to create the p folder. After this is done, the container quits.

My script pings the sync container and when it goes down, starts the Dgraph server.

Any other way to do that???