When you say you have it configured, do you mean the “key” field? I have found that you do not need to set that. To send the output of Jenkins jobs to logstash, only set:
Jenkins -> Manage Jenkins -> Logstash
1. indexer type to ‘syslog’
2. hostname to logstash
3. port to $logstash_port
If you have a lot of output going to logstash, you might have json parse errors which would prevent proper indexing to elasticsearch. Check the records in elasticsearch around the time that you would expect to see the Jenkins output as it might not be typed properly. One way to troubleshoot this is to set the max lines from the job going to logstash to something small, like 5, and then check to see if you are sending data properly. Also, be sure to use the post build action to send output to logstash.