# Codec rubydebug output not showing in 'docker logs' output

**URL:** <https://discuss.elastic.co/t/codec-rubydebug-output-not-showing-in-docker-logs-output/47799>\
**Category:** Logstash\
**Created:** [April 19, 2016, 2:10pm UTC](https://discuss.elastic.co/t/codec-rubydebug-output-not-showing-in-docker-logs-output/47799 "2016-04-19T14:10:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Alex\_Harvey](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alex_harvey/32/32183_2.png) [@Alex\_Harvey](https://discuss.elastic.co/u/Alex_Harvey)\
**Post date:** [April 19, 2016, 2:10pm UTC](https://discuss.elastic.co/t/codec-rubydebug-output-not-showing-in-docker-logs-output/47799/1 "2016-04-19T14:10:50Z")

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I am trying to debug the official Logstash Docker container. All available documentation I can find seems to imply that if I add an output `stdout { codec => rubydebug }`, I should be able to see this in `docker logs`. It's not working for me, however, although if I add `--debug` to the command line, I can see all that debug output fine.

Anyone have any clues on what I could be doing wrong?

In some more detail:

```
# docker pull docker.io/logstash
# docker run -v -d /path/to/logstash.conf:/etc/logstash/logstash.conf --name logstash logstash logstash -f /etc/logstash/logstash.conf

```

And in logstash.conf

```
output {
  stdout {
    codec => rubydebug
  }
}
```

---

<div class="post-metadata">

**Author:** ![Alex\_Harvey](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alex_harvey/32/32183_2.png) [@Alex\_Harvey](https://discuss.elastic.co/u/Alex_Harvey)\
**Post date:** [May 13, 2016, 11:32am UTC](https://discuss.elastic.co/t/codec-rubydebug-output-not-showing-in-docker-logs-output/47799/3 "2016-05-13T11:32:21Z")

</div>

This was a newbie mistake. The root cause was not exposing the port to the Docker container, and the fix is adding a flag to the docker run command `-p 6782:6782`.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 4:57am UTC](https://discuss.elastic.co/t/codec-rubydebug-output-not-showing-in-docker-logs-output/47799/4 "2017-07-06T04:57:41Z")

</div>