Example of running multiple microservices talking to each other in Micronaut / Docker / Kubernetes
So the point of this example is demonstrating simpy how to:
- build a couple of Micronaut microservices
- package them in Docker images
- deploy them in a Kubernetes deployment
- have Kubnernetes set up DNS so the services can call each other
To run/test:
- run
build.sh- this will build the Micronaut apps and create docker images - run
kubectl apply -f micronaut-multiple-services-kubernetes.yaml- this will - curl localhost:8080/greetings | jq
Note that there are two microservices:
- 'name service' - GET /names returns a random name
- 'greeting service' - GET /greetings retrieves a random name from the name serivce and returns a greeting 'hello <random name>'
The Kubernetes deployment file (micronaut-multiple-services-kubernetes.yaml)
- deploys the services (with appropriate 'liveness' checks)
- sets up a LoadBalancer service for the greeting service, to expose it externally
- sets up a NodePort service for the name serivce, so the greeting service can call the name serivce via
GET http://name-service-loadbalancer:8080/names(see NameServiceClient)
Please see this page for the relevant Kubernetes docs: https://kubernetes.io/docs/concepts/services-networking/connect-applications-service/