KEDA

https://keda.sh/docs/2.14/scalers/
https://keda.sh/

https://keda.sh/docs/2.14/concepts/

Agent — KEDA activates and deactivates Kubernetes Deployments to scale to and from zero on no events. This is one of the primary roles of the keda-operator container that runs when you install KEDA.

Metrics — KEDA acts as a Kubernetes metrics server that exposes rich event data like queue length or stream lag to the Horizontal Pod Autoscaler to drive scale out. It is up to the Deployment to consume the events directly from the source. This preserves rich event integration and enables gestures like completing or abandoning queue messages to work out of the box. The metric serving is the primary role of the keda-operator-metrics-apiserver container that runs when you install KEDA.

Admission Webhooks - Automatically validate resource changes to prevent misconfiguration and enforce best practices by using an admission controller. As an example, it will prevent multiple ScaledObjects to target the same scale target.

helm repo add kedacore https://kedacore.github.io/charts
helm repo update
helm pull kedacore/keda --version=2.14.0

docker pull ghcr.io/kedacore/keda-admission-webhooks:2.14.0
docker pull ghcr.io/kedacore/keda-metrics-apiserver:2.14.0
docker pull ghcr.io/kedacore/keda:2.14.0

docker save -o keda-admission-webhooks-2140.tar 5e7a029c7981
docker save -o keda-metrics-apiserver-2140.tar 789f6a8835d9
docker save -o keda-2140.tar 90f874bd572a

helm install keda kedacore/keda -n keda --create-namespace

object 만들기, 가능한 메트릭이 여러개 있지만, 일단 간단하게 cpu로 확인 ( sqs연결시 iam oidc 연결 필요 )

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

cat <<EOF | kubectl apply -f -
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: nginx-cpu-scaler 
spec:
  scaleTargetRef:
    name: nginx-test
    kind: Deployment
    apiVersion: apps/v1
  fallback:
    failureThreshold: 4
    replicas: 5
  minReplicaCount: 1
  maxReplicaCount: 10
  triggers:
  - type: cpu
    metricType: Utilization
    metadata:
      value: "50"  # CPU 사용률이 50%를 초과하면 새 파드를 생성
EOF


cat <<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: nginx-test
  name: nginx-test
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx-test
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx-test
    spec:
      containers:
      - image: nginx
        name: nginx
        resources:
          requests:
            cpu: 20m
          limits:
            cpu: 100m
EOF

kubectl get hpa
NAME                        REFERENCE               TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
keda-hpa-nginx-cpu-scaler   Deployment/nginx-test   0%/50%    1         10        1          10m

keda prometheus 연결
https://keda.sh/docs/2.14/operate/prometheus/

keda cron

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: cron-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: my-deployment
  minReplicaCount: 0
  cooldownPeriod: 300
  triggers:
  - type: cron
    metadata:
      timezone: Asia/Kolkata
      start: 0 6 * * *
      end: 0 20 * * *
      desiredReplicas: "10"

http object참고
https://medium.com/@carlocolumna/how-to-scale-your-pods-based-on-http-traffic-d58221d5e7f1

https://github.com/kedacore/http-add-on/blob/main/docs/ref/v0.2.0/http_scaled_object.md