当 Kubernetes 中的 configmap 更新时刷新 daemonset pod

Question

更新配置映射后，如何自动重启与 Daemonsets 关联的 Kubernetes pod？

根据configmap 卷挂载更新时的kubernetes文档，它会自动更新 pod。但是，我认为 Daemonsets 不会发生这种情况。我错过了什么？

下面是我的配置图

apiVersion: v1
kind: ConfigMap
metadata:
  name: fluent-bit-update
  namespace: default
  labels:
    k8s-app: fluent-bit
data:
  # Configuration files: server, input, filters and output
  # ======================================================
  fluent-bit.conf: |
    [SERVICE]
        Flush         1
        Log_Level     info
        Daemon        off
        Parsers_File  parsers.conf


    @INCLUDE input-kubernetes.conf
    @INCLUDE filter-kubernetes.conf
    @INCLUDE output-logaggregator.conf

  input-kubernetes.conf: |
    [INPUT]
        Name              tail
        Tag               kube.*
        Path              /var/log/containers/abc.log
        Parser            docker
        DB                /var/log/tail-containers-state.db
        DB.Sync           Normal
        Mem_Buf_Limit     5MB
        Skip_Long_Lines   On
        Refresh_Interval  10
        Rotate_Wait      60
        Docker_Mode      On

  filter-kubernetes.conf: |

    [FILTER]
        Name                kubernetes
        Match               kube.*
        Kube_URL            https://kubernetes.default.svc:443
        Kube_CA_File        /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        Kube_Token_File     /var/run/secrets/kubernetes.io/serviceaccount/token
        Kube_Tag_Prefix     kube.var.log.conatiners.
        Merge_Log           On
        Keep_Log            Off
        K8S-Logging.Parser  On
        K8S-Logging.Exclude Off
        Labels              On
        Annotations         On

  output-kubernetes.conf: |

    [OUTPUT]
        Name              cloudwatch
        Match             kube.*
        region            us-west-2
        log_group_name    fluent-bit-cloudwatch
        log_stream_prefix from-fluent-bit
        auto_create_group true

  parsers.conf: |

    [PARSER]
        Name         docker
        Format       json
        Time_Key     time
        Time_Format  %Y-%m-%dT%H:%M:%S.%L
        Time_Keep    On
        Decode_Field_As   escaped_utf8    log    do_next
        Decode_Field_As   json       log

    [PARSER]
        Name         docker_default
        Format       json
        Time_Key     time
        Time_Format  %Y-%m-%dT%H:%M:%S.%L
        Time_Keep    On

& 我的守护进程清单文件

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: fluent-bit-update
  namespace: default
  labels:
    k8s-app: fluent-bit-logging
    version: v1
    kubernetes.io/cluster-service: "true"
spec:
  template:
    metadata:
      labels:
        k8s-app: fluent-bit-logging
        version: v1
        kubernetes.io/cluster-service: "true"
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "2020"
        prometheus.io/path: /api/v1/metrics/prometheus
    spec:
      containers:
        - name: aws-for-fluent-bit
          image: amazon/aws-for-fluent-bit:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 2020
          volumeMounts:
            - name: varlog
              mountPath: /var/log
            - name: varlibdockercontainers
              mountPath: /var/lib/docker/containers
              readOnly: true
            - name: fluent-bit-volume
              mountPath: /fluent-bit/etc/
      terminationGracePeriodSeconds: 10
      volumes:
        - name: varlog
          hostPath:
            path: /var/log
        - name: varlibdockercontainers
          hostPath:
            path: /var/lib/docker/containers
        - name: fluent-bit-volume
          configMap:
            name: fluent-bit-update
      serviceAccountName: fluent-bit
      tolerations:
        - key: node-role.kubernetes.io/master
          operator: Exists
          effect: NoSchedule
        - operator: "Exists"
          effect: "NoExecute"
        - operator: "Exists"
          effect: "NoSchedule"

当我更新Pathconfigmap 中的字段以读取另一个日志文件时，虽然我看到卷挂载正在更新，但除非我删除并重新创建守护程序集，否则我看不到 pod 获取更改。

有没有办法在不重新启动守护进程的情况下自动实现这一目标？我很感激这方面的一些指导。谢谢

Answer 1

kubectl rollout restart  ds/<daemonset_name> -n namespace

这些将进行滚动更新并更新 configMap。

Answer 2

根据您指出的文档，Kubernetes 将更新 configmap（在您的情况下为 fluent-bit 配置），但您的应用程序有责任选择更新的配置。通常，应用程序在启动时获取配置，但要定期更新配置，您的应用程序应支持此配置或应使用另一个模块（如配置更新程序），当有一个更改配置。对于 fluent-bit，您可以参考这个github 问题进行动态配置。Prometheus 已经支持这样了。