Sample project combining the build system Bazel with a java service written in Spring, deploying to a local Kubernetes cluster.

To start with, this project assumes that you are on a system where java means java 8 and python on version 2.

Install minikube and start it up.

$ minikube start \
  --kubernetes-version=v1.10.8 \
  --memory=8192 \
  --cpus=4

Feel free to launch the kubernetes dashboard by now and inspect your handiwork in the cluster.

$ minikube dashboard

Install bazel and use it to build all code in the repository, this can be a little slow the first time but should be rapid after that.

$ bazel build //...

We can also run all tests to verify that everything works.

$ bazel test //...

Before we can deploy anything there has to be a repository which the build system can push and from where the cluster can pull images. We'll set up a simple one inside minikube.

$ kubectl create -f deployment/infrastructure/registry/kube-registry.yaml

Then forward the port to localhost so that your local system can reach it. Note that this command does not exit and must run as long as you want to publish new images to the registry.

$ kubectl port-forward --namespace kube-system $(kubectl get pods -n kube-system -l 'k8s-app=kube-registry,version=v0' -o name) 5000:5000

The registry is now set up within kubernetes and shared with your local machine which is good enough for Linux. If you're on Mac you still need to forward it from your local machine to your Linux VM in which you run docker. We can do that by running socat in a container.

$ docker run --rm --privileged \
    --pid=host gsunner/ubuntu-socat \
    nsenter -t 1 -u -n -i socat TCP-LISTEN:5000,fork TCP:docker.for.mac.host.internal:5000

Lets test the setup by deploying the last build version of the user service to our cluster.

$ bazel run //deployment/service/user:full.apply

There is a rather nice plugin for IntelliJ available that you might want to use. Unfortunately it's not compatible with the latest version of the IDE at the time of writing so I have a pre built version waiting for you in the tools/intellij folder. If you want to build it yourself, clone the repository and build it with

$ bazel build //ijwb:ijwb_bazel_zip --define=ij_product=intellij-ue-2018.2

When that is done, you are ready to import the project. Choose the root of the repository as the WORKSPACE and generate from the BUILD file located under service/user/BUILD

A common element in development setups are helper tools that monitors your source code and react to changes as soon as they are saved to the filesystem. For bazel there is iBazel which unfortunately needs to be built from source. With it installed you can ask it to keep an eye on the tests for the user service. It will hook into bazel and figure out which dependencies you have and re-run the tests automatically as soon as a dependent file is changed.

$ ibazel test //service/user:tests

You can even set it up to build and deploy any changes straight into your cluster.

$ ibazel run //service/user:deploy.apply