Brewlet Kubernetes platform

This repository contains the Kubernetes-facing components of Brewlet:

• the node lifecycle and JavaApplication controllers;
• the pod and NodeProfile admission webhook;
• the NodeProfile and JavaApplication API types and CRDs;
• raw Kubernetes deployment manifests; and
• the Brewlet Helm chart.

The runtime shim and node provisioner source live in brewlet/brewlet. Architecture and API specifications live in brewlet/specs, and the user documentation lives in brewlet/site.

Install with Helm

helm install brewlet ./charts/brewlet \
  --set provisioner.jdks="temurin-21,microsoft-25" \
  --set provisioner.launchers="jaz"

The chart installs the CRDs, operator, admission webhook, and the RBAC used by the operator-managed node provisioner. The default NodeProfile targets every unclaimed node. Configure named profiles when provisioning should be restricted to platform-owned node pools.

kubectl get nodeprofiles
kubectl get nodes -L brewlet.sh/runtime

See the Brewlet installation guide for cluster prerequisites and production configuration.

Custom JDK distributions

temurin and microsoft use built-in image mappings. For another distribution, provide its fully qualified OCI image and Java home directly in the NodeProfile. For example, Azul Zulu 21:

apiVersion: node.brewlet.sh/v1alpha1
kind: NodeProfile
metadata:
  name: zulu
spec:
  nodePool:
    names: ["zulu-workers"]
  jdks:
    - distribution: zulu
      feature: 21
      source:
        image: docker.io/library/azul-zulu:21
        javaHome: /usr/lib/jvm/zulu21

Use a digest-pinned image in production. The image must support every architecture in the selected pool, contain <javaHome>/bin/java, and provide the runtime's required userland libraries. javaHome may point to a centrally built jlink runtime; Brewlet installs it once per node pool rather than placing it in each application artifact.

Install raw manifests

kubectl apply -f deploy/nodeprofile-crd.yaml
kubectl apply -f deploy/javaapplication-crd.yaml
kubectl apply -f deploy/node-provisioner.yaml
kubectl apply -f config/operator.yaml
kubectl apply -f deploy/sample-nodeprofile.yaml

The raw manifests use these images:

Component	Image
Operator	ghcr.io/brewlet/operator
Admission webhook	ghcr.io/brewlet/admission
Node provisioner	ghcr.io/brewlet/node-provisioner

Build and test

The Go module is rooted at the repository root.

make build
make test
make test-envtest
make helm-check

Build the component images with the repository root as the Docker context:

docker build -t ghcr.io/brewlet/operator:dev .
docker build -t ghcr.io/brewlet/admission:dev . --build-arg CMD=admission

Repository layout

.
├── api/                 NodeProfile and JavaApplication API types
├── charts/brewlet/      Helm chart and packaged CRDs
├── cmd/manager/         Kubernetes operator
├── cmd/admission/       Admission webhook
├── config/              Raw operator RBAC and Deployment
├── deploy/              CRDs, samples, and raw manifests
└── internal/            Controllers, admission logic, and tests

License

MIT