Sidekiq Middleware registered in the wrong order with Batches when used with Sidekiq Pro

[eapache-opslevel]

When using activerecord-multi-tenant with the paid Sidekiq-Pro gem, sidekiq batch callbacks do not have a tenant set by default, even if the original job and batch were enqueued inside a tenant block.

Given the following example job:

class TestJob
  include Sidekiq::Job

  def perform
    puts "perform"
    puts MultiTenant.current_tenant
  end

  def callback(status, options)
    puts "callback"
    puts MultiTenant.current_tenant
  end
end

and the following execution (assuming 1 is a valid tenant ID):

MultiTenant.with(1) do
  b = Sidekiq::Batch.new
  b.on(:success, "TestJob#callback")
  b.jobs { TestJob.perform_async }
end

You will find that while the tenant is set correctly in perform, it is not set in callback. This is because of a middleware ordering issue between the multitenant code and the sidekiq-pro batch code.

We were able to work around this issue by manually removing and re-ordering the middleware in our own initializer:

# Fix middleware order so that Sidekiq Batch Callbacks are run with a tenant set
chain.remove(Sidekiq::Middleware::MultiTenant::Client)
chain.insert_before(Sidekiq::Batch::Client, Sidekiq::Middleware::MultiTenant::Client)

(and the same thing for the server middleware, and the client middleware on the server).

---

Given that this is a sidekiq-builtin feature, it would be nice if this gem could check for the presence of the Batch middleware and insert its middleware in the correct spot by default.