Boxxspring Worker SDK

The Boxxspring workers gem provides the base functionality for other Boxxspring workers, such as Youtube Workers, Feed Workers, Subscription Workers, etc.

Worker base

• The worker has a queue that is subscribed a topic (Amazon SQS). Usually there's only one topic for each environemnt, e.g. staging-tasks.

# lib/boxxspring/worker/base.rb
@queue_interface ||= Aws::SQS::Client.new

• As it receives messages from the topic, it proccesses the payload from the message:

self.receive_messages()
payload = self.payload_from_message( message )
self.process_payload( payload )

• If there's an error with the payload, the worker will log the error:

rescue StandardError => error
  self.logger.error(
    "The #{ self.human_name } worker failed to process the payload."
  )
  self.logger.error( error.message )
  self.logger.info( error.backtrace.join( "\n" ) )

• Messages are deleted if the payload is invalid or not meant for it self.delete_message( message )

• The worker can delegate_payload by forwarding a message to another queue

Task Base

• When the worker receives a payload process_payload( payload ), it attempts to read the task, and throws an error if the task can't be retrieved or if there's a SignalException.

• If the task is valid, it is delegated to process_task( task ), which is defined in each individual worker.

• The default task_state for a task received by the worker is idle.

• The methods beloeve are available to workers inheriting from Boxxspring::Worker::TaskBase:

• task_write(task): Updates the task in the database with new values assigned to task attributes & returns the task.

• task_write_state(task, state, message): Updates the task state and message with the arguments and returns the updated task.

• operation(endpoint) is a short hand Boxxspring::Operation. Example:

Boxxspring::Operation.new(
  "/properties/#{property_id}/tasks/#{task_id}",
  Worker.configuration.api_credentials.to_hash
)

Environment variables

• LOG_LEVEL: When set to debug, the worker will log messages that are restricted to debug mode.