Merge pull request #56 from EmilS/plugins/kafka-consumer-readme

Adds README for Kafka consumer plugin

plugins/kafka_consumer/README.md

@@ -0,0 +1,24 @@
+# Kafka Consumer
+
+The [Kafka](http://kafka.apache.org/) consumer plugin polls a specified Kafka
+topic and adds messages to InfluxDB. The plugin assumes messages follow the
+line protocol. [Consumer Group](http://godoc.org/github.com/wvanbergen/kafka/consumergroup)
+is used to talk to the Kafka cluster so multiple instances of telegraf can read
+from the same topic in parallel.
+
+## Testing
+
+Running integration tests requires running Zookeeper & Kafka. The following
+commands assume you're on OS X & using [boot2docker](http://boot2docker.io/).
+
+To start Kafka & Zookeeper:
+
+```
+docker run -d -p 2181:2181 -p 9092:9092 --env ADVERTISED_HOST=`boot2docker ip` --env ADVERTISED_PORT=9092 spotify/kafka
+```
+
+To run tests:
+
+```
+ZOOKEEPER_PEERS=$(boot2docker ip):2181 KAFKA_PEERS=$(boot2docker ip):9092 go test
+```