Exchanging messages using port forwarding

Prerequisite

Before you start, you need to have access to a running Kubernetes cluster environment. A Minikube instance running on your laptop will do fine.

Start minikube with a parametrized dns domain name 

minikube start --profile tutorialtester
minikube profile tutorialtester

* [tutorialtester] minikube v1.32.0 on Fedora 40
* Automatically selected the docker driver. Other choices: kvm2, qemu2, ssh
* Using Docker driver with root privileges
* Starting control plane node tutorialtester in cluster tutorialtester
* Pulling base image ...
* Creating docker container (CPUs=2, Memory=15900MB) ...
* Preparing Kubernetes v1.28.3 on Docker 24.0.7 ...
  - Generating certificates and keys ...
  - Booting up control plane ...
  - Configuring RBAC rules ...
* Configuring bridge CNI (Container Networking Interface) ...
  - Using image gcr.io/k8s-minikube/storage-provisioner:v5
* Verifying Kubernetes components...
* Enabled addons: storage-provisioner, default-storageclass
* Done! kubectl is now configured to use "tutorialtester" cluster and "default" namespace by default
* minikube profile was successfully set to tutorialtester

Enable nginx and ssl passthrough for minikube 

minikube addons enable ingress
minikube kubectl -- patch deployment -n ingress-nginx ingress-nginx-controller --type='json' -p='[{"op": "add", "path": "/spec/template/spec/containers/0/args/-", "value":"--enable-ssl-passthrough"}]'

* ingress is an addon maintained by Kubernetes. For any concerns contact minikube on GitHub.
You can view the list of minikube maintainers at: https://github.com/kubernetes/minikube/blob/master/OWNERS
  - Using image registry.k8s.io/ingress-nginx/controller:v1.9.4
  - Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v20231011-8b53cabe0
  - Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v20231011-8b53cabe0
* Verifying ingress addon...
* The 'ingress' addon is enabled
deployment.apps/ingress-nginx-controller patched

Make sure the domain of your cluster is resolvable

If you are running your OpenShift cluster locally, you might not be able to resolve the urls to IPs out of the blue. Follow this guide to configure your setup.

This tutorial will follow the simple /etc/hosts approach, but feel free to use the most appropriate one for you.

Deploy the operator

create the namespace 

kubectl create namespace send-receive-project
kubectl config set-context --current --namespace=send-receive-project

namespace/send-receive-project created
Context "tutorialtester" modified.

Go to the root of the operator repo and install it:

./deploy/install_opr.sh

Deploying operator to watch single namespace
Client Version: 4.15.0-0.okd-2024-01-27-070424
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Kubernetes Version: v1.28.3
customresourcedefinition.apiextensions.k8s.io/activemqartemises.broker.amq.io created
customresourcedefinition.apiextensions.k8s.io/activemqartemisaddresses.broker.amq.io created
customresourcedefinition.apiextensions.k8s.io/activemqartemisscaledowns.broker.amq.io created
customresourcedefinition.apiextensions.k8s.io/activemqartemissecurities.broker.amq.io created
serviceaccount/activemq-artemis-controller-manager created
role.rbac.authorization.k8s.io/activemq-artemis-operator-role created
rolebinding.rbac.authorization.k8s.io/activemq-artemis-operator-rolebinding created
role.rbac.authorization.k8s.io/activemq-artemis-leader-election-role created
rolebinding.rbac.authorization.k8s.io/activemq-artemis-leader-election-rolebinding created
deployment.apps/activemq-artemis-controller-manager created

Wait for the Operator to start (status: running).

kubectl wait pod --all --for=condition=Ready --namespace=send-receive-project --timeout=600s

pod/activemq-artemis-controller-manager-55b8c479df-2nxqd condition met

Deploying the ActiveMQ Artemis Broker

For this tutorial we need to:

  • have a broker that is able to listen to any network interface. For that we setup an acceptor that will be listening on every interfaces on port 62626.
  • have queues to exchange messages on. These are configured by the broker properties. Two queues are setup, one called APP.JOBS that is of type ANYCAST and one called APP.COMMANDS that is of type MULTICAST.
kubectl apply -f - <<EOF
apiVersion: broker.amq.io/v1beta1
kind: ActiveMQArtemis
metadata:
  name: send-receive
  namespace: send-receive-project
spec:
  acceptors:
    - bindToAllInterfaces: true
      name: acceptall
      port: 62626
  brokerProperties:
    - addressConfigurations."APP.JOBS".routingTypes=ANYCAST
    - addressConfigurations."APP.JOBS".queueConfigs."APP.JOBS".routingType=ANYCAST
    - addressConfigurations."APP.COMMANDS".routingTypes=MULTICAST
EOF

activemqartemis.broker.amq.io/send-receive created

Wait for the Broker to be ready:

kubectl wait ActiveMQArtemis send-receive --for=condition=Ready --namespace=send-receive-project --timeout=240s

activemqartemis.broker.amq.io/send-receive condition met

Exchanging messages between a producer and a consumer

Download the latest release of ActiveMQ Artemis, decompress the tarball and locate the artemis executable.

wget --quiet https://dlcdn.apache.org/activemq/activemq-artemis/2.36.0/apache-artemis-2.36.0-bin.tar.gz
tar -zxf apache-artemis-2.36.0-bin.tar.gz apache-artemis-2.36.0/

# First we need to start port forwarding
kubectl port-forward send-receive-ss-0 62626 -n send-receive-project &

# Then produce and consume some messages
./artemis producer --destination APP.JOBS  --url tcp://localhost:62626
./artemis consumer --destination APP.JOBS  --url tcp://localhost:62626

# Finally we need to kill the port forwarding
pkill kubectl -9

Forwarding from 127.0.0.1:62626 -> 62626
Forwarding from [::1]:62626 -> 62626
Connection brokerURL = tcp://localhost:62626
Handling connection for 62626
Handling connection for 62626
Producer ActiveMQQueue[APP.JOBS], thread=0 Started to calculate elapsed time ...

Producer ActiveMQQueue[APP.JOBS], thread=0 Produced: 1000 messages
Producer ActiveMQQueue[APP.JOBS], thread=0 Elapsed time in second : 8 s
Producer ActiveMQQueue[APP.JOBS], thread=0 Elapsed time in milli second : 8766 milli seconds
Connection brokerURL = tcp://localhost:62626
Consumer:: filter = null
Handling connection for 62626
Handling connection for 62626
Consumer ActiveMQQueue[APP.JOBS], thread=0 wait until 1000 messages are consumed
Received 1000
Consumer ActiveMQQueue[APP.JOBS], thread=0 Consumed: 1000 messages
Consumer ActiveMQQueue[APP.JOBS], thread=0 Elapsed time in second : 0 s
Consumer ActiveMQQueue[APP.JOBS], thread=0 Elapsed time in milli second : 68 milli seconds
Consumer ActiveMQQueue[APP.JOBS], thread=0 Consumed: 1000 messages
Consumer ActiveMQQueue[APP.JOBS], thread=0 Consumer thread finished

cleanup

To leave a pristine environment after executing this tutorial you can simply, delete the minikube cluster.

minikube delete --profile tutorialtester

* Deleting "tutorialtester" in docker ...
* Deleting container "tutorialtester" ...
* Removing /home/tlavocat/.minikube/machines/tutorialtester ...
* Removed all traces of the "tutorialtester" cluster.
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