Introduction#

GitHub this note shows

  • Explain EC2 Nodegroup in EKS
  • Explain Fargate Profile in EKS
  • Demo Fargate Profile

Architecture#

amazon eks fargate profile
  • Fargate profile managed by AWS in an AWS VPC
  • Firecracker is used to create lightweight VM
  • One Pod per VM, more isolation, but a bit more overload
  • Two ENI, one to connect Faragate VPC, one to connect to user's VPC
  • Faragate serverless pricing0

Faragate Profile#

Add a fargate profile to a EKS cluster in CDK. Use namespace and labels to select the Faragate profile to run pods you want on Faragate.

// fargate profile for app
const appFargateProfile = new aws_eks.CfnFargateProfile(
  this,
  'FirstFargateProfileDemo1',
  {
    clusterName: cluster.name!,
    podExecutionRoleArn: podRole.roleArn,
    selectors: [
      {
        namespace: 'demo',
        labels: [
          {
            key: 'environment',
            value: 'dev'
          }
        ]
      }
    ],
    fargateProfileName: 'demo',
    // default all private subnet in the vpc
    subnets: subnets,
    tags: [
      {
        key: 'name',
        value: 'test'
      }
    ]
  }
)

To exclude Faragate profiles from installing deamonset, we can use affinity (nodeselector)

affinity:
  nodeAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      nodeSelectorTerms:
        - matchExpressions:
            - key: eks.amazonaws.com/compute-type
              operator: NotIn
              values:
                - fargate

Deploy App#

Deploy a simple app in Faragate profile

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
  namespace: demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: webapp
      environment: dev
  template:
    metadata:
      labels:
        app: webapp
        environment: dev
    spec:
      containers:
        - name: go
          image: public.ecr.aws/awsvijisarathy/prometheus-webapp:latest
          imagePullPolicy: Always
          resources:
            requests:
              cpu: '256m'
              memory: '512Mi'
            limits:
              cpu: '256m'
              memory: '512Mi'

get and describe the nodes

kubectl get nodes
kubectl describei node farget-profile-node-xxx

change the cpu requests to 10240 and check that a new Faragate (node) will be created and rolling updates happens

Reference#