# Does the input and output plugins support variables?

**URL:** <https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160>\
**Category:** Logstash\
**Created:** [April 21, 2017, 7:49am UTC](https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160 "2017-04-21T07:49:12Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kvin](https://avatars.discourse-cdn.com/v4/letter/k/e99b99/32.png) [@Kvin](https://discuss.elastic.co/u/Kvin)\
**Post date:** [April 21, 2017, 7:49am UTC](https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160/1 "2017-04-21T07:49:13Z")

</div>

I'm trying to set up a pipeline configuration with the following input filter:

```
rabbitmq {
	exchange => "exchange"
	host => "%{HOST}"
	queue => "queue"
	durable => true
	ack => true
	threads => 1
	prefetch_count => 1000
	password => "%{PWD}"
	user => "%{USER}"
}

```

The variables, %{HOST}, %{PWD} and %{USER} should be read from environmental variables, but Logstash complains in the logs that it can not connect to %{HOST}, because it takes it as a literal string.

I'm using 5.2.

What could cause this?

---

<div class="post-metadata">

**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [April 21, 2017, 8:41am UTC](https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160/2 "2017-04-21T08:41:20Z")

</div>

To read environment variables use `${FOO}`, not `%{FOO}`.

---

<div class="post-metadata">

**Author:** ![Kvin](https://avatars.discourse-cdn.com/v4/letter/k/e99b99/32.png) [@Kvin](https://discuss.elastic.co/u/Kvin)\
**Post date:** [April 21, 2017, 11:29am UTC](https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160/3 "2017-04-21T11:29:42Z")

</div>

Thank you! That was it.

---

<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:** [May 19, 2017, 11:35am UTC](https://discuss.elastic.co/t/does-the-input-and-output-plugins-support-variables/83160/4 "2017-05-19T11:35:17Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.