K8S学习之基础二十七：k8s中daemonset控制器

news2025/3/16 22:29:08

k8s中DaemonSet控制器

DaemonSet控制器确保k8s集群中，所有节点都运行一个相同的pod，当node节点增加时，新节点也会自动创建一个pod，当node节点从集群移除，对应的pod也会自动删除。删除DaemonSet也会删除创建的pod。

DaemonSet控制器会监听k8s的ds对象、pod对象、node对象，这些被监听的对象变动，就会出发syncLoop循环让k8s集群朝着ds对象魔术的状态进行演进。

应用场景：

在集群每个节点运行存储，如glusterd或ceph

在每个节点运行日志收集组件：如flunentd、logstash、filebeat

在每个节点运行监控组件，如Prometheus、NodeExporter、collectd

以fluntend测试

上传镜像fluentd到harbor

vi daemonset-flunted.yaml 
kind: DaemonSet
metadata:
  name: fluentd-elasticsearch
  namespace: kube-system            # 定义命名空间
  labels:
    k8s-app: fluentd-logging        # 定义标签
spec:
  selector:
    matchLabels:
      name: fluentd-elasticsearch   # 匹配标签，与pod一致
  template:
    metadata:
      labels:
        name: fluentd-elasticsearch  # pod标签
    spec:
      tolerations:                # 定义容忍度，因为要在master上部署
      - key: node-role.kubernetes.io/control-plane
        operator: Exists
        effect: NoSchedule        # 容忍度调度
      containers:
      - name: fluentd-elasticsearch
        image: 172.16.80.140/fluented/fluented:v2.5.1   # harbor镜像地址
        resources:           # 资源配额
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:                              # 挂载卷
        - name: varlog
          mountPath: /var/log                     # 监控/var/log
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers   # 监控容器日志
          readOnly: true
      terminationGracePeriodSeconds: 30
      volumes:
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers