Production containers now copy the Zeppelin source files at
build-time rather than using a shared volume. This means fewer
permission issues and backend/dashboard builds only have to run once
at build-time, not every time the containers are started.
Docs in PRODUCTION.md have been updated accordingly.
The env var now only affects the bot container, not the API.
This is because we don't currently need this extra debug information
for the API.
For the bot, with DEBUG set, the bot container will now start and do
nothing. To start the bot in this container in debug mode, open a
shell into the container and run the start-bot-prod-debug script
manually. This change was made to allow more control over what
profiling scripts and other things are run in the debug environment.
This makes the prepare_backend container (which runs migrations) wait
until the mysql server is actually running, not just the container.
Thanks to Skyz on Discord for the implementation.
