spin kube plugin

A Spin plugin for interacting with Kubernetes.

Install

Install the stable release:

spin plugins update
spin plugins install kube

Compiling from source

As an alternative to the plugin manager, you can download and manually install the plugin. Manual installation is commonly used to test in-flight changes. For a user, it's better to install the plugin using Spin's plugin manager.

Ensure the pluginify plugin is installed:

spin plugins update
spin plugins install pluginify --yes

Fetch the plugin:

git clone git@github.com:spinkube/spin-plugin-kube.git
cd spin-plugin-kube

Compile and install the plugin:

make
make install

Prerequisites

Ensure spin-operator is installed in your Kubernetes cluster. See the spin-operator Quickstart Guide.

Usage

Install the wasm32-wasi target for Rust:

rustup target add wasm32-wasi

Create a Spin application:

spin new --accept-defaults -t http-rust hello-rust
cd hello-rust

Compile the application:

spin build

Publish your application:

docker login
spin registry push bacongobbler/hello-rust:latest

Deploy to Kubernetes:

spin kube scaffold --from bacongobbler/hello-rust:latest | kubectl create -f -

View your application:

kubectl get spinapps

spin kube scaffold deploys two replicas by default. You can change this with the --replicas flag:

spin kube scaffold --from bacongobbler/hello-rust:latest --replicas 3 | kubectl apply -f -

Delete the app:

kubectl delete spinapp hello-rust

Autoscaler support

Autoscaler support can be enabled by setting --autoscaler and by setting a CPU limit and a memory limit.

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler hpa --cpu-limit 100m --memory-limit 128Mi

Setting min/max replicas:

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler hpa --cpu-limit 100m --memory-limit 128Mi --replicas 1 --max-replicas 10

CPU/memory limits and CPU/memory requests can be set together:

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler hpa --cpu-limit 100m --memory-limit 128Mi --cpu-request 50m --memory-request 64Mi

IMPORTANT!
    CPU/memory requests are optional and will default to the CPU/memory limit if not set.
    CPU/memory requests must be lower than their respective CPU/memory limit.

Setting the target CPU utilization:

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler hpa --cpu-limit 100m --memory-limit 128Mi --autoscaler-target-cpu-utilization 50

Setting the target memory utilization:

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler hpa --cpu-limit 100m --memory-limit 128Mi --autoscaler-target-memory-utilization 50

KEDA support:

spin kube scaffold --from bacongobbler/hello-rust:latest --autoscaler keda --cpu-limit 100m --memory-limit 128Mi

Working with images from private registries

Support for pulling images from private registries can be enabled by using --image-pull-secret <secret-name> flag, where <secret-name> is a secret of type docker-registry in same namespace as your SpinApp.

To enable multiple private registries, you can provide the flag --image-pull-secret multiple times with secret for each registry that you wish to use.

Create a secret with credentials for private registry

$) kubectl create secret docker-registry registry-credentials \
  --docker-server=ghcr.io \
  --docker-username=bacongobbler \
  --docker-password=github-token

secret/registry-credentials created

Verify that the secret is created

$) kubectl get secret registry-credentials -o yaml

apiVersion: v1
data:
  .dockerconfigjson: eyJhdXRocyI6eyJnaGNyLmlvIjp7InVzZXJuYW1lIjoiYmFjb25nb2JibGVyIiwicGFzc3dvcmQiOiJnaXRodWItdG9rZW4iLCJhdXRoIjoiWW1GamIyNW5iMkppYkdWeU9tZHBkR2gxWWkxMGIydGxiZz09In19fQ==
kind: Secret
metadata:
  creationTimestamp: "2024-02-27T02:18:53Z"
  name: registry-credentials
  namespace: default
  resourceVersion: "162287"
  uid: 2e12ddd1-919d-44b5-b6cc-c3cd5c09fcec
type: kubernetes.io/dockerconfigjson

Use the secret when scaffolding the SpinApp

$) spin kube scaffold --from bacongobbler/hello-rust:latest --image-pull-secret registry-credentials

apiVersion: core.spinoperator.dev/v1alpha1
kind: SpinApp
metadata:
  name: hello-rust
spec:
  image: "bacongobbler/hello-rust:latest"
  executor: containerd-shim-spin
  replicas: 2
  imagePullSecrets:
    - name: registry-credentials