title: Logstash grok pattern for space field
body: <p>Hi How to write a grok expression for the below log </p>
  
  <pre><code>[2017-03-25T00:00:07,137][WARN ]
  
  match =&gt; { "message" =&gt; "\[%{TIMESTAMP_ISO8601:timestamp}/]/[%{LOGLEVEL:log-level}\s*\]" }
  </code></pre>
  
  <p>Is this correct , how to write space in grok ? 
  Thanks </p>