sample-keda-metrics-api

README

KEDA Sample for Metrics API

A simple Docker container written in go that will expose metrics. This metrics will be used with for a Keda scaler Metrics APi

$ curl http:localhost:8090/api/value

Sample response:

{
    payload: {
        value: 0
    },
    success: true,
    error: ""
}

And one endpoint to update the metric.

$ curl --location --request POST 'http://localhost:8090/api/value/10'

Docker image

You can access the image by pulling from DockerHub.

docker pull adoborroto/sample-keda-metrics-api:latest

Setup

1. Deploy Keda in a cluster.
2. Deploy metric api

apiVersion: apps/v1
kind: Deployment
metadata:
  name: metrics-deployment
  labels:
    app: metrics
spec:
  replicas: 1
  selector:
    matchLabels:
      app: metrics
  template:
    metadata:
      labels:
        app: metrics
    spec:
      containers:
      - name: metrics
        image: adoborroto/sample-keda-metrics-api:latest
        ports:
        - containerPort: 8090
        imagePullPolicy: IfNotPresent

1. Deploy the app that you want to scale based on the metric

apiVersion: apps/v1
kind: Deployment
metadata:
  name: testapp-deployment
spec:
  selector:
    matchLabels:
      app: testapp
  replicas: 1
  template:
    metadata:
      labels:
        app: testapp
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

1. Setup the Keda metric scaler

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: http-scaledobject
  namespace: default
  labels:
    deploymentName: http-scaled
spec:
  maxReplicaCount: 5
  scaleTargetRef:
    name: testapp-deployment
  triggers:
    - type: metrics-api
      metadata:
        targetValue: "2"
        url: http://your-service-metrics-here
        valueLocation: 'payload.value'