In this tutorial we install Apache Camel K on minikube. Apache Camel K is a lightweight integration framework built from Apache Camel that runs natively on Kubernetes and is specifically designed for serverless and microservice architecture. You can follow the video or continue reading.

Prerequisites

• Docker installed
• Minikube installed

Download and install camel-k cli

Download the camel-k cli binary for your Operating System from here. I am using version 1.2.0. You put the binary on your path.

Start the cluster

I am using the Docker driver for this Tutorial. I start minikube with this command:

minikube start --driver=docker

After a minute or so the cluster should be up and running. If minikube fails to start, see the drivers page for help setting up a compatible container or virtual-machine manager.

Add the registry addon to the minikube cluster.

minikube addons enable registry

Install camel-k

To install the camel-k operator type

kamel install

Test the installation with the command

kamel get
NAME    PHASE   KIT

You get an empty list of integrations. Let’s change this.

Deploy the sample code

Download the sample code from here and unzip it. Change to the unzipped directory.

Start activemq docker container

For testing we need a running Apache ActiveMQ instance. We use an existing docker image and start the container like this

    docker run -p 61616:61616 -p 8161:8161 rmohr/activemq

Access the admin console and login with de default user admin and password admin.

The sample code looks like this

    public class ActivemqTransacted extends RouteBuilder {

        @Override
        public void configure() {

            from("activemq:inqueue").throwException(IllegalArgumentException.class, "bad message");
            
        }

    }

We listen on a queue named inqueue for messages and throw immedietly an IllegalArgumentException. If we send a message to the inqueue the DefaultErrorHandler kicks in and the exception will be propagated back to the caller and the Exchange ends immediately. Let’s have a look on the application.properties file. Please replace the IP Adresse in the broker-url with your IP.

    # transactionsautowired props
    camel.component.activemq.broker-url=tcp://192.168.0.129:61616
    camel.component.activemq.transacted=false

Now we deploy the camel-k integration with this command

    kamel run --dev --property-file src/main/resources/application.properties src/main/java/ch/dulce/ActivemqTransacted.java

The integration get’s built and deployed to our minikube instance. Access the admin console and login with de default user admin and password admin. Go to the Queues tab. We should see a queue named inqueue. Klick on the right side under Operations on Send To and send a test message. Enable Persistent Delivery like this

Click on the send button. We see the IllegalArgumentException thrown and the message get’s consumed (lost)! Now let’s enable the transacted attribute in the application.properties file.

    # transactionsautowired props
    camel.component.activemq.broker-url=tcp://192.168.0.129:61616
    camel.component.activemq.transacted=true <- set to true

The integration should get redeployed automatically since we used the kamel --dev flag. Send another test message to the inqueue. This time the message is not lost because activemq rolls back the transaction on the IllegalArgumentException and redelivers the message until the activemq broker default redelivery times (6) is reached. Then the message will be sent to a Dead Letter Queue (DLQ).

Type Ctrl-C in the window where you executed the kamel run command to undeploy the integration.

Summary

In this tutorial we installed camel-k on minikube. And made some test wit a simple integration using activemq with transactions.