Akka Cluster Orchestration Example

Project Status

Lightbend Orchestration is no longer actively developed and will reach its End of Life on April 15, 2020.

We recommend Migrating to the Improved Kubernetes Deployment Experience.

Summary

This is a very simple Akka Cluster and Akka HTTP application. Its main purpose is to show how you can build a similar application and take advantage of the Lightbend Orchestration for Kubernetes to easily and safely deploy to Kubernetes with minimal configuration required.

Deployment

Prerequisites:

• reactive-cli
• Minikube

You'll need version 0.9.0 (or later) of the CLI.

If you already have a Minikube and wish to start fresh, run minikube delete to remove your existing Minikube.

1. Start minikube

minikube start

eval $(minikube docker-env)

minikube addons enable ingress

2. Build and Deploy project

There's two ways to deploy this project. You can do it from within SBT or from the command line.

SBT

This is the developer friendly method of running the project. Simply invoke the deploy minikube task.

sbt 'deploy minikube'

Command Line

This matches more closely what you'd do in a production environment. You'll build the project. Then, you'll use rp to generate resources for it and pipe those to kubectl.

Build project

sbt docker:publishLocal

Inspect images

docker images

Deploy project

rp generate-kubernetes-resources akka-cluster-orchestration-example:0.1.0 \
  --generate-all \
  --ingress-annotation ingress.kubernetes.io/rewrite-target=/ \
  --ingress-annotation nginx.ingress.kubernetes.io/rewrite-target=/ \
  --pod-controller-replicas 3 | kubectl apply -f -

3. View Results (Note: -k is needed because the certificate is self-signed)

This may take 30 seconds or so until all pods have been started and the cluster has formed. You should see a member listing.

kubectl get all

NAME                                               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deploy/akka-cluster-orchestration-example-v0-1-0   3         3         3            3           1m

NAME                                                      DESIRED   CURRENT   READY     AGE
rs/akka-cluster-orchestration-example-v0-1-0-6d8b954c45   3         3         3         1m

NAME                                               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deploy/akka-cluster-orchestration-example-v0-1-0   3         3         3            3           1m

NAME                                                      DESIRED   CURRENT   READY     AGE
rs/akka-cluster-orchestration-example-v0-1-0-6d8b954c45   3         3         3         1m

NAME                                                      READY     STATUS    RESTARTS   AGE
po/akka-cluster-orchestration-example-v0-1-0-6d8b954c45-2jzbb   1/1       Running   0          1m
po/akka-cluster-orchestration-example-v0-1-0-6d8b954c45-vfkg6   1/1       Running   0          1m
po/akka-cluster-orchestration-example-v0-1-0-6d8b954c45-zq8wj   1/1       Running   0          1m

NAME                                     TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                         AGE
svc/akka-cluster-orchestration-example   ClusterIP   None         <none>        10000/TCP,10001/TCP,10002/TCP   1m
svc/kubernetes                           ClusterIP   10.96.0.1    <none>        443/TCP                         3m

curl -k "https://$(minikube ip)/cluster-example"

Akka Cluster Members
====================

akka.tcp://[email protected]:10000
akka.tcp://[email protected]:10000
akka.tcp://[email protected]:10000

4. Run the job (Optional)

This application has a job in it that joins the existing cluster, prints a message, and then exits.

rp generate-kubernetes-resources akka-cluster-orchestration-example:0.1.0 \
  --application my-job \
  --akka-cluster-join-existing \
  --generate-pod-controllers \
  --pod-controller-type job | kubectl apply -f -

You can then inspect the jobs output using:

kubectl logs jobs/akka-cluster-orchestration-example-v0-1-0

And lastly, remove the job, thus deleting logs:

kubectl delete jobs/akka-cluster-orchestration-example-v0-1-0

5. Remove project (Optional)

If you wish to remove the resources, you can use kubectl delete as follows:

rp generate-kubernetes-resources akka-cluster-orchestration-example:0.1.0 \
  --generate-all --pod-controller-replicas 3 | kubectl delete -f -