DaemonSet and HPA

DaemonSet

Through configuration, add daemonSet automatically

Example

Give Node a Label

kubectl label nodes k8s-node1 svc_type=microsvc

Then, in daemonSet configuration, config the nodeSelector

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd
spec:
  selector:
    matchLabels:
      app: logging
  template:
    metadata:
      labels:
        app: logging
        id: fluentd
      name: fluentd
    spec:
      nodeSelector:
        type: microsvc
      containers:
      - name: fluentd-es
        image: agilestacks/fluentd-elasticsearch:latest
        env:
         - name: FLUENTD_ARGS
           value: -qq
        volumeMounts:
         - name: containers
           mountPath: /var/lib/docker/containers
         - name: varlog
           mountPath: /varlog
      volumes:
         - hostPath:
             path: /var/lib/docker/containers
           name: containers
         - hostPath:
             path: /var/log
           name: varlog

Add label to node

kubectl label no node1 type=microsvc

HPA (Horizontal Pod Autoscaler)

Automatically scale the number of pods by monitoring CPU, memory usage, or custom metrics.

This is generally used with Deployments and is not suitable for objects that cannot be scaled, such as DaemonSets.

The controller checks resource usage metrics every 30 seconds (adjustable with the –horizontal-pod-autoscaler-sync-period option).

kubectl autoscale deploy nginx-deploy --cpu-percent=20 --min=2 --max=5
kubectl get hpa