April 12, 2020

Using kaf for Azure EventHub

Since kaf v0.1.35 it is now possible to interact with Azure EventHub. Kaf is a modern CLI to interact with Kafka, i.e. producing data, consuming, or viewing topic and Consumer Group information. Now having first-class support for EventHub makes EventHub much more accessible than before. In the following Example i’ll show how to set up kaf for your EventHub. It’s very simple.

Install kaf

There’s several ways to install kaf.

Install script

curl https://raw.githubusercontent.com/birdayz/kaf/master/godownloader.sh | BINDIR=$HOME/bin bash


yay -S kaf

Via Go

go get github.com/birdayz/kaf/cmd/kaf

Setup EventHub

To create an EventHub, you have to first create an EventHubs namespace. The equivalent to a EventHub Namespace in the Kafka world is a Kafka Cluster.

This can be either done on the Portal, or via CLI:

az eventhubs namespace create --name joe-test-2 --resource-group my-resource-group

This command may take some minutes to complete.

Since quite some time, the Kafka compatibility mode is enabled by default for all new EventHub Namespaces, so you don’t need to explicitly enable it.

After creating the EventHub Namespace, you have to create an EventHub. The equivalent to an EventHub is a Kafka Topic.

az eventhubs eventhub create -g my-resource-group --namespace-name joe-test-2 --name iot-data

Now that we created the Namespace (Cluster) and the EventHub (Topic), we still need a way to access it. For this, a Connection String is used. It can be obtained via either Portal, or the Azure CLI:

az eventhubs namespace authorization-rule keys list -g my-resource-group --namespace-name joe-test-2 --name RootManageSharedAccessKey | jq -r '.primaryConnectionString'

This prints out the Connection String to your EventHub Namespace. If you don’t have jq installed, you can omit the jq command and copy the primaryConnectionString by hand.

Configure kaf

Configuring kaf to use the eventhub is very straight-forward; run the following command:

kaf config add-eventhub my-eventhub --eh-connstring $(az eventhubs namespace authorization-rule keys list -g my-resource-group --namespace-name joe-test-2 --name RootManageSharedAccessKey | jq -r '.primaryConnectionString')
Added EventHub.

Note: Replace joe-test-2 with your EventHub Namespace name.

To ensure that kaf sets your new EventHub Namespace as the active cluster, run

kaf config use-cluster my-eventhub
Switched to cluster "my-eventhub".

Run commands

Now you can use kaf to interact with your EventHub.

List Topics (EventHubs):

kaf topics
iot-data   4            0

You see, the EventHub we previously created is shown under topics.

We can go a step further. We can create a new topic, which means that a new EventHub is created within this EventHub Namespace:

kaf topic create second-topic -p 2
✅ Created topic!
      Topic Name:            second-topic
      Partitions:            2
      Replication Factor:    1
      Cleanup Policy:        delete

List topics:

kaf topics
iot-data       4            0
second-topic   2            0

Even the Azure Portal shows the created topic (EventHub):


Consuming and Producing data:

To consume, run

kaf consume second-topic

To produce, run

echo test | kaf produce second-topic
Sent record to partition 1 at offset 0.

The consume command will output the message:

Partition:   1
Offset:      0
Timestamp:   2020-04-12 23:40:01.591 +0200 CEST

Cleaning up

Don’t forget to delete your EventHub if you just used it to try kaf out.