akka-microservice-sample

This is a akka kubernetes deployment example. It runs on minikube and uses the newest akka-management release and the sbt native packager for container creation.

• A backend service which starts a akka cluster on 3 nodes (pods) and counts the greeting count for a given name
• A frontend service which uses akka discovery to get the gRPC endpoint of service 1 to ask the cluster

Quickstart

Steps to run the demo cluster:

• install minikube brew cask install minikube
• configure docker eng in terminal eval $(minikube docker-env)
• go to k8s folder cd k8s
• run build script ./build-images.sh
• configure kubernetes cluster roles before first run kubectl apply -f rbac-init.yaml
• run service 1 (backend) first kubectl apply -f service1.yaml
• run service 2 (frontend) kubectl apply -f service2.yaml
• get your minikube ip minikube ip
• get the service port of your NodePort Service 2 kubectl get services
• call you minikube ip on the given NodePort with your favorite browser - The http result should be Service 2 is ok
  • if this doesn't work use minikube service service2 which shows the URL you have to use and opens your favourite browser - The http result in the browser should be Service 2 is ok
• call the get path greet with a name e.g http://192.168.99.100:32462/greet/innFactory - The http result should be something like Hello innFactory - The actorsystem greeted you 1 times!

Update service

Example for service1:

• make your code changes
• in the file service1/build.sbt update the version in Docker value to 0.2 for example
• go to k8s folder cd k8s
• run build script ./build-images.sh
• rollout new version kubectl set image deployment/service1 service1=innfactory-test/service1:0.2
• check the status of the deployment with kubectl get pods

Monitoring and Tracing

There are 3 branches with different tools for monitoring and tracing:

• branch lightbend_monitoring: Simple Monitoring example with Lightbend Monitoring.
  • folder lightbend_monitoring in the lightbend_monitoring branch.
• branch kamon_jaeger: Monitoring example with Kamon and tracing example with Jaeger.
  • folder monitoring-and-tracing in the kamon_jaeger branch.
• branch istio: Example Istio integration.
  • folder istio in the istio branch.

Notes

ServiceDiscovery is made with akka discovery and a bit dirty, because it does not use the cluster ip of service 1 for the grpc calls. It just tooks the first resolution address from the pod list with selector app=service1 and blocks service2 with Await. For a production use-case this should be changed and the the grpc client binding should use the result of the kubernetes-api-discovery from future and not from Await with hard .get!!!. Logging is also very dirty and there are a lot of println.

Blogpost

• English
• German

Contributors

• Tobias Jonas
• Michael List

innFactory - Cloud Engineering Experts - akka, grpc, k8s, kubernetes