Module: Dcmgr::Helpers::CliHelper

Defined Under Namespace

Classes: CommandError, TimeoutError

Instance Method Summary collapse

Instance Method Details

#sh(cmd, args = [], opts = {}) ⇒ Object



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# File 'lib/dcmgr/helpers/cli_helper.rb', line 55

def sh(cmd, args=[], opts={})
  opts = opts.merge({:expect_exitcode=>0})
  cmd = sprintf(cmd, *args.map {|a| Shellwords.shellescape(a.to_s) })

  outbuf = errbuf = ''
  blk = proc {|pid, stdin, stdout, stderr|
    stdin.close
    outbuf = stdout.read
    errbuf = stderr.read
  }
  stat = Open4::popen4(cmd, &blk)
  if self.respond_to?(:logger)
    logger.debug("Exec command (pid=#{stat.pid}): #{cmd}")
    msg = "Command output:"
    msg << "\nSTDOUT:\n#{outbuf.strip}" if outbuf && outbuf.strip.size > 0
    msg << "\nSTDERR:\n#{errbuf.strip}" if errbuf && errbuf.strip.size > 0
    logger.debug(msg)
  end
  if stat.exitstatus != opts[:expect_exitcode]
    raise CommandError.new("Unexpected exit code=#{stat.exitstatus} (expected=#{opts[:expect_exitcode]})", \
      outbuf, errbuf)
  end
  {:stdout => outbuf, :stderr => errbuf}
end

#tryagain(opts = {:timeout=>60, :retry=>3}, &blk) ⇒ Object



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# File 'lib/dcmgr/helpers/cli_helper.rb', line 13

def tryagain(opts={:timeout=>60, :retry=>3}, &blk)
  timedout = false
  curthread = Thread.current

  timersig = EventMachine.add_timer(opts[:timeout]) {
    timedout = true
    if curthread && curthread.alive?
      curthread.raise(TimeoutError.new("timeout"))
      begin
        curthread.pass
      rescue ::Exception => e
        # any thread errors can be ignored.
      end
    end
  }

  count = opts[:retry]
  begin
    begin
      break if blk.call
    end while !timedout && ((count -= 1) >= 0)
  rescue TimeoutError => e
    raise e
  rescue RuntimeError => e
    if respond_to?(:logger)
      logger.debug("Caught Error. To be retrying....: #{e}")
    end
    retry if (count -= 1) >= 0
  ensure
    EventMachine.cancel_timer(timersig) rescue nil
  end
end