Test Kitchen integration tests with Chefspec: testing cookbook with dependencies

Question

I understand that Test Kitchen follows the sequence

create node > converge cookbook > run tests

What is the best practice to create a test that assumes a strong external dependency?

An example is the Kafka cookbook https://supermarket.chef.io/cookbooks/kafka. As you might know, Kafka is a messaging broker application that depends on Zookeeper, a separate application that is the message hub.

Following proper separation of concerns, the Kafka cookbook does not include Zookeeper - it can be installed in the same host or in a different machine.

However in order to do a simple verification if Kafka is working, (i.e. create a simple message), you need to have a Zookeeper server running.

For example, the test could be running these three commands after installation

# creates a message topic
bin/kafka-create-topic.sh --zookeeper localhost:2181 --replica 1 --partition 1 --topic test

# lists existing message topics
bin/kafka-list-topic.sh --zookeeper localhost:2181

# sends a message to this machine
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test

Using Chefspec, is there a way to stub this external server (the localhost:2181 part above)?

Thank you!

Answer 1

Two parts to the answer: first ChefSpec is used for unit testing, and is unrelated to Test Kitchen and integration testing. Second, you would need to make a minimal test recipe to install a 1-node ZK server and use that for integration testing. Generally you would do this by putting a test cookbook under test/cookbook and then add it to your Berksfile with a path source. You could use a "real" ZK cookbook, or you could use something simpler and more dedicated. Just an example of minimalism for testing, see my MongoDB recipe. You can probably use something similar for ZK in this situation.