FlameK8s

Kubernetes backend integration for FLAME.

This library implements FLAME.Backend and delegates runner lifecycle to Kubernetes through the FlameRunner and FlamePool custom resources managed by the flame-k8s operator.

Installation

Add the dependency to your mix.exs:

def deps do

  [

    {:flame_k8s, "~> 0.1.0"}

  ]

end

Configure Your Application

Enable the backend in your runtime configuration (usually in production):

if config_env() == :prod do

  config :flame, :backend, FLAME.K8sBackend

  config :flame, FLAME.K8sBackend,

    log: :debug,

    boot_timeout: 30_000

end

How It Works

  1. Your app invokes FLAME work (FLAME.call/3, FLAME.cast/3).
  2. FLAME.K8sBackend creates a FlameRunner custom resource.
  3. The operator reconciles FlameRunner and creates the runner pod.
  4. The runner pod connects back via distributed Erlang.
  5. Work executes remotely and runner resources are cleaned up.

Install The Operator

This backend requires the operator and CRDs installed in the target cluster.

Option 1: use project release manifest.

kubectl apply -f <release-manifest-url>

Option 2: generate manifests from this repository and apply with kustomize.

make generate-k8s-manifests

kubectl apply -k .k8s/install/manifests

Generate A FLAME-Ready Deployment

The library includes a mix task that generates a Deployment with the FLAME annotations already filled in.

mix flame.gen.deployment \

  --name flame-parent-example \

  --namespace default \

  --image ghcr.io/eigr-labs/flame-parent-example:latest

Optional flags include --pool-config-ref, --otp-app, --cookie-secret-ref, and --runner-termination-timeout.

Apply Example CR Instances

After installing the operator, apply example resources:

kubectl apply -f examples/crds/flamepool-apply.yaml

kubectl apply -f examples/flame_example/.k8s/deployment.yaml

The direct FlameRunner manifest is still available for manual CR testing, but the normal application flow is driven by the annotated Deployment and the mutating webhook.

Inspect status:

kubectl get flamepools -A

kubectl get flamerunners -A

Environment Notes