Sidekiq compatible background workers in golang.

• reliable queueing for all queues using brpoplpush
• handles retries
• support custom middleware
• customize concurrency per queue
• responds to Unix signals to safely wait for jobs to finish before exiting.
• provides stats on what jobs are currently running
• redis sentinel support
• well tested

Example usage:

package main

import (
	"github.com/digitalocean/go-workers2"
)

func myJob(message *workers.Msg) error {
  // do something with your message
  // message.Jid()
  // message.Args() is a wrapper around go-simplejson (http://godoc.org/github.com/bitly/go-simplejson)
  return nil
}

func myMiddleware(queue string, mgr *Manager, next JobFunc) JobFunc {
  return func(message *workers.Msg) (err error) {
    // do something before each message is processed
    err = next()
    // do something after each message is processed
    return
  }
}

func main() {
  // Create a manager, which manages workers
  manager, err := workers.NewManager(Options{
    // location of redis instance
    ServerAddr: "localhost:6379",
    // instance of the database
    Database:   0,
    // number of connections to keep open with redis
    PoolSize:   30,
    // unique process id for this instance of workers (for proper recovery of inprogress jobs on crash)
    ProcessID:  "1",
  })

  // create a middleware chain with the default middlewares, and append myMiddleware
  mids := workers.DefaultMiddlewares().Append(myMiddleware)

  // pull messages from "myqueue" with concurrency of 10
  // this worker will not run myMiddleware, but will run the default middlewares
  manager.AddWorker("myqueue", myJob, 10)

  // pull messages from "myqueue2" with concurrency of 20
  // this worker will run the default middlewares and myMiddleware
  manager.AddWorker("myqueue2", myJob, 20, mids...)

  // pull messages from "myqueue3" with concurrency of 20
  // this worker will only run myMiddleware
  manager.AddWorker("myqueue3", myJob, 20, myMiddleware)

  // Create a producer to enqueue messages
  producer, err := workers.NewProducer(Options{
    // location of redis instance
    ServerAddr: "localhost:6379",
    // instance of the database
    Database:   0,
    // number of connections to keep open with redis
    PoolSize:   30,
    // unique process id for this instance of workers (for proper recovery of inprogress jobs on crash)
    ProcessID:  "1",
  })
  // Alternatively, if you already have a manager and want to enqueue
  // to the same place:
  producer := manager.Producer()

  // Add a job to a queue
  producer.Enqueue("myqueue3", "Add", []int{1, 2})

  // Add a job to a queue with retry
  producer.EnqueueWithOptions("myqueue3", "Add", []int{1, 2}, workers.EnqueueOptions{Retry: true})

  // stats will be available at http://localhost:8080/stats
  go workers.StartStatsServer(8080)

  // Blocks until process is told to exit via unix signal
  manager.Run()
}

Development sponsored by DigitalOcean. Code forked from github/jrallison/go-workers. Initial development sponsored by Customer.io.