Simplify initializing and running the Worker

[andrewgy8]

One consistent peice of feedback that I have received is simplifying the Worker class. Right now, you must Initialize with the subs, each individual config attribute, run setup, run start, and then sleep.

Like this:

worker = Worker(
    [photo_uploaded],
    config.gc_project_id,
    config.credentials,
    config.ack_deadline,
)
worker.setup()
worker.start()
sleep(120)

I propose we simplify the API to run a worker to look something like this instead:

worker = Worker([photo_uploaded], config)
worker.run(sleep=120)

run would call both setup and start, and we could add the standard sleep method. In addition we consolidate the configuration into one attribute.

This would be backwards compatible since we will be creating a new method. And the change to Worker initialization could also fall back to the declared attributes if defined. Otherwise, use the config object.

[tobami]

Sounds like a great plan to me!

[craigmulligan]

Not sure this is convenient or possible but If you already have an api for setting up rele singleton with the required config, can't the worker use that api too? Then the setup for publishing and the Worker would be the same?

eg

# config.setup should always be called first.
rele.config.setup({
    'GC_CREDENTIALS': service_account.Credentials.from_service_account_file(
        GOOGLE_APPLICATION_CREDENTIALS
    ),
    'GC_PROJECT_ID': GOOGLE_PROJECT_ID,
})

worker = rele.Worker(
    [photo_uploaded],
)
worker.setup()
worker.start()
sleep(120)

[tobami]

That's certainly an option! We could make the config parameters optional in case the config was already initialized

[andrewgy8]

Released in #131