Resque 作业无法连接到外部主机

Question

在我的 Rails 应用程序中，我设置了 ActiveJob 以使用 Resque。我创建了这个作业来发送带有grocer gem 的 iOS 推送通知：

class SendPushNotificationJob < ActiveJob::Base
  queue_as :default

  def perform(device_token, msg)
    # TODO: Move the grocer initialization somewhere else.
    pusher = Grocer.pusher(
      certificate: ENV['PUSH_CERT_PATH'],
      passphrase:  ENV['PUSH_CERT_KEY'],
      gateway:     "gateway.sandbox.push.apple.com",
      port:        2195,
      retries:     3
    )

    Resque.logger.debug "PUSHER OBJECT IS #{pusher.inspect}!"

    notification = Grocer::Notification.new(
    device_token: device_token,
    alert: msg)

    Resque.logger.debug "NOTIFICATION OBJECT IS #{notification.inspect}"

    res = pusher.push(notification)

    Resque.logger.debug "PUSH RESULT IS #{res.inspect}"
  end
end

这个job被接时Resque日志的输出是：

** [22:08:31 2016-07-06] 24074: Found job on default
** [22:08:31 2016-07-06] 24074: got: (Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"SendPushNotificationJob", "job_id"=>"c88619a4-d2ea-4b27-a3c8-3ea5be04a130", "queue_name"=>"default", "arguments"=>["<my_device_token>", "Test message"], "locale"=>"en"}])
** [22:08:31 2016-07-06] 24074: resque-1.26.0: Processing default since 1467860911 [ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper]
** [22:08:31 2016-07-06] 24074: Running before_fork hooks with [(Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"SendPushNotificationJob", "job_id"=>"c88619a4-d2ea-4b27-a3c8-3ea5be04a130", "queue_name"=>"default", "arguments"=>["<my_device_token>", "Test message"], "locale"=>"en"}])]
** [22:08:31 2016-07-06] 24074: resque-1.26.0: Forked 24092 at 1467860911
** [22:08:31 2016-07-06] 24092: Running after_fork hooks with [(Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"SendPushNotificationJob", "job_id"=>"c88619a4-d2ea-4b27-a3c8-3ea5be04a130", "queue_name"=>"default", "arguments"=>["<my_device_token>", "Test message"], "locale"=>"en"}])]
** [22:08:31 2016-07-06] 24092: PUSHER OBJECT IS #<Grocer::Pusher:0x007f862152f4f0 @connection=#<Grocer::Connection:0x007f862152f630 @certificate="<cert path>", @passphrase="<passphrase>", @gateway="gateway.sandbox.push.apple.com", @port=2195, @retries=3>>!
** [22:08:31 2016-07-06] 24092: NOTIFICATION OBJECT IS #<Grocer::Notification:0x007f8627a23f00 @identifier=0, @device_token="<my_device_token>", @alert="Test message", @encoded_payload=nil>

然后异常发生：

** [22:08:31 2016-07-06] 24092: (Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"SendPushNotificationJob", "job_id"=>"c88619a4-d2ea-4b27-a3c8-3ea5be04a130", "queue_name"=>"default", "arguments"=>["<my_device_token>", "Test message"], "locale"=>"en"}]) failed: #<SocketError: getaddrinfo: nodename nor servname provided, or not known>

这是我所知道的：

1. 网关 URL 设置正确。
2. 环境变量设置正确。
3. 当使用 perform_now 而不是 perform_later 时，此作业有效。

最后，grocer 不是问题。我创建了另一个只记录 URL 来源的作业：

class TestExternalConnectionJob < ActiveJob::Base
  queue_as :default

  def perform(url)
    res = HTTParty.get(url)

    if res
      Resque.logger.debug "SUCCESS"
      Resque.logger.debug res.body
    else
      Resque.logger.debug "FAILURE"      
    end
  end
end

在 Rails 控制台中运行 TestExternalConnectionJob.perform_later('http://stackoverflow.com') 会在 Resque 日志中生成以下输出：

** [22:14:41 2016-07-06] 24285: Found job on default
** [22:14:41 2016-07-06] 24285: got: (Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"TestExternalConnectionJob", "job_id"=>"523da5ca-2b6c-452e-95ef-33edece69996", "queue_name"=>"default", "arguments"=>["http://stackoverflow.com"], "locale"=>"en"}])
** [22:14:41 2016-07-06] 24285: resque-1.26.0: Processing default since 1467861281 [ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper]
** [22:14:41 2016-07-06] 24285: Running before_fork hooks with [(Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"TestExternalConnectionJob", "job_id"=>"523da5ca-2b6c-452e-95ef-33edece69996", "queue_name"=>"default", "arguments"=>["http://stackoverflow.com"], "locale"=>"en"}])]
** [22:14:41 2016-07-06] 24285: resque-1.26.0: Forked 24300 at 1467861281
** [22:14:41 2016-07-06] 24300: Running after_fork hooks with [(Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"TestExternalConnectionJob", "job_id"=>"523da5ca-2b6c-452e-95ef-33edece69996", "queue_name"=>"default", "arguments"=>["http://stackoverflow.com"], "locale"=>"en"}])]
** [22:14:41 2016-07-06] 24300: (Job{default} | ActiveJob::QueueAdapters::ResqueAdapter::JobWrapper | [{"job_class"=>"TestExternalConnectionJob", "job_id"=>"523da5ca-2b6c-452e-95ef-33edece69996", "queue_name"=>"default", "arguments"=>["http://stackoverflow.com"], "locale"=>"en"}]) failed: #<SocketError: Failed to open TCP connection to stackoverflow.com:80 (getaddrinfo: nodename nor servname provided, or not known)>

所以，tl;dr，我的 Resque 作业都无法连接到外部服务。

附录

我的lib/resque.rake 文件：

require 'resque/tasks'

namespace :resque do
  task :setup => :environment do
    require 'resque'
  end
end

我的config/initializers/resque.rb 文件：

require 'resque'

Resque.redis = Redis.new(url: 'redis://127.0.0.1:6379')
Resque.logger = Logger.new(Rails.root.join('log', "#{Rails.env}_resque.log"))
Resque.logger.level = Logger::DEBUG
Resque.after_fork = Proc.new { ActiveRecord::Base.establish_connection }

Answer 1

嗯，写这个问题是非常浪费时间。

由于某种原因，在重新启动并重新启动我的所有进程后，我能够连接到外部主机。

以前，我多次重启进程没有重启。我正在使用eye 来管理它们，所以为了解决这个问题，我多次发出eye restart 命令来重新启动我的应用程序所依赖的所有进程（postgres、redis 和resque-worker）。每次重启后我都会得到同样的错误。

但不知何故，重启就成功了。

计算机有时很奇怪。