How to combine middleware with batches

[iamtheschmitzer]

I have middleware to set custom attributes when pushing a job, and then use them in the worker.

When a batch callback is triggered, the worker middleware is invoked, but it doesn't look like the client middleware is (custom attributes are missing). In this case, the job is triggered by the batch, not by client code.

Is this a bug/limitation, or am I just missing how to setup the middleware for batch callbacks, or is there something to do when creating the batch?

Thanks

[iamtheschmitzer]

Looks like I found the answer - in the batch success setting, I was able to set custom

    batch.success = { jobtype: FooBatchCallback, args: [options],
                      queue: 'foo_priority', custom: { bar: 'baz } }

[mperham]

Well done for figuring it out. This is documented here:

https://github.com/contribsys/faktory/wiki/Ent-Batches#callbacks

but not with Ruby code. How can we document it better?

Fundamentally you're constructing a job payload, as defined here:

https://github.com/contribsys/faktory/wiki/The-Job-Payload

and custom is meant to provide persistence for the broader environment around the job payload: thread-locals, Rails CurrentAttributes, golang's context, etc.

Side note: I feel like we should make an effort to look into renaming custom, I think env or context are objectively better names for its intended use and so clearer to a developer's mental model. env would be my choice.