http4k on k8s
Bootstrapped minimal http4k app with inbuilt support for k8s using this guide.
Different stages of transition of the app onto k8s
- Run locally using
gradle - Run using
docker - Run using
docker compose - Run on k8s using
kubectl - Run on k8s using
helm
For steps 1 to 3, you reach application by
curl -v http://localhost:8081/liveness
curl -v http://localhost:8081/readiness
curl http://localhost:8080/pingFor step 4 & 5, only http://localhost:8080/ping is exposed.
liveness and readiness probes are not exposed.
Instead they are used internally by k8s.
./gradlew run./gradle installdocker build --tag backend .
docker imagesUse --detach instead of --rm to run in background.
docker run \
--name backend \
--publish "8080:8080" \
--publish "8081:8081" \
--rm \
backend
docker ps -a
docker rm -f backenddocker compose up --build
docker ps -a
docker compose downEnable k8s in Docker Desktop for macOS.
Check which k8s you are connected to.
kubectl config get-contexts
kubectl config use-contexts docker-desktopkubectl get nodesIf you are not using [default] namespace, you will have to pass --namespace {{custom_namespace}}.
[Optional] Install k8s dashboard
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.7.0/aio/deploy/recommended.yamlkubectl apply -f k8s/k8s-backend.yaml
kubectl get services
kubectl get deployments
kubectl get pods
kubectl delete service backend-service
kubectl delete deployment backend-apphelm install backend-app helm/backend