Helios Event Senders
===

There is support to send events on Helios cluster updates.

From helios masters, the following events are sent:

Topic `HeliosDeploymentGroupEvents` with a `DeploymentGroupEvent` message,
see `com.spotify.helios.rollingupdate.DeploymentGroupEventFactory`.

From helios agents:

Topic `HeliosTaskStatusEvents` with a `HeliosTaskStatusEvent` message,
see `com.spotify.helios.common.descriptors.TaskStatusEvent`.


There is support to send events over Kafka, and over Google PubSub.


Kafka
---

Using the command line argument `--kafka <broker>`, Kafka publishing is enabled. The Kafka sender creates a KafkaRecord from the
topic and message as is.

GooglePubSub
---

Using the command line argument `--pubsub-topic-prefix <topic-prefix>`, Google PubSub publishing is enabled. The Google PubSub sender
concatenates the topic prefix with the the helios event topic (with no separator), and sends the message as payload.

Add event sender .md file.
Add event sender .md file.
