title: Print a string to stdout using Logstash 1.4?
body: <p>So I was testing this config for using metrics from the Logstash website <a href="http://logstash.net/docs/1.4.2/filters/metrics" rel="nofollow">here</a>.</p>
  
  <pre><code>input {
    generator {
      type =&gt; "generated"
    }
  }
  
  filter {
    if [type] == "generated" {
      metrics {
        meter =&gt; "events"
        add_tag =&gt; "metric"
      }
    }
  }
  
  output {
    # only emit events with the 'metric' tag
    if "metric" in [tags] {
      stdout {
        message =&gt; "rate: %{events.rate_1m}"
      }
    }
  }
  </code></pre>
  
  <p>But it looks like the "message" field for stdout was deprecated. What is the correct way to do this in Logstash 1.4?</p>