nginx-ingress-controller日志持久化方案

时间  2020-03-31
标签 nginx ingress controller 日志 持久 方案 栏目 Nginx 繁體版
原文   原文链接

最近看到一篇公众号讲了nginx-ingress-controller的应用。下面有人评论如何作日志持久化，恰好工做上遇到该问题，整理一个方案，仅供参考。node

nginx-ingress-controller的日志

nginx-ingress-controller的日志包括三个部分：nginx

  • controller日志： 输出到stdout，经过启动参数中的–log_dir可已配置输出到文件，重定向到文件后会自动轮转，但不会自动清理
  • accesslog：输出到stdout，经过nginx-configuration中的字段能够配置输出到哪一个文件。输出到文件后不会自动轮转或清理
  • errorlog：输出到stderr，配置方式与accesslog相似。

给controller日志落盘

  1. 给nginx-ingress-controller挂一个hostpath： /data/log/nginx_ingress_controller/ 映射到容器里的/var/log/nginx_ingress_controller/ ，
  2. 给nginx-ingress-controller配置log-dir和logtostderr参数，将日志重定向到/var/log/nginx_ingress_controller/中。

controller的日志须要作定时清理。因为controller的日志是经过klog(k8s.io/klog)输出的，会进行日志滚动，因此咱们经过脚本定时清理必定时间以前的日志文件便可。docker

给nginx日志落盘

  1. 修改configmap： nginx-configuration。配置accesslog和errorlog的输出路径，替换默认的stdout和stderr。输出路径咱们能够与controller一致，便于查找。

  2. accesslog和errorlog都只有一个日志文件，咱们可使用logrotate进行日志轮转，将输出到宿主机上的日志进行轮转和清理。配置如：api

    $ cat /etc/logrotate.d/nginx.log
/data/log/nginx_ingress_controller/access.log {
    su root list
    rotate 7
    daily
    maxsize 50M
    copytruncate
    missingok
    create 0644 www-data root
}
  3. 官方提供的模板中，nginx-ingress-controller默认都是以33这个用户登陆启动容器的，所以挂载hostpath路径时存在权限问题。咱们须要手动在机器上执行chown -R 33:33 /data/log/nginx_ingress_controller.

自动化ops

nginx日志落盘中，第二、3两点均须要人工运维，有什么解决办法吗？bash

问题的关键是：有什么办法能够在nginx-ingress-controller容器启动以前加一个hook，将宿主机的指定目录执行chown呢？app

能够用initContainer。initcontainer必须在containers中的容器运行前运行完毕并成功退出。利用这一k8s特性，咱们开发一个docker image，里面只执行以下脚本：运维

#!/bin/bash
logdir=$LOG_DIR
userID=$USER_ID
echo "try to set dir: $logdir 's group as $userID"
chown  -R  $userID:$userID $logdir

脚本读取一些环境变量， 确认须要修改哪一个目录，改为怎样的user group。tcp

将脚本打包成dockerimage， 放在nginx-ingress-controller的deploy yaml中，做为initcontainers。 注意要对该initcontainer配置环境变量和volumeMount.ui

再说第二点，咱们注意到nginx-ingress-controller的基础镜像中就自带了logrotate，那么问题就简单了，咱们将写好的logrotate配置文件以configmap的形式挂载到容器中就能够了。spa

一个deploy yaml以下：

---
apiVersion: v1
kind: Service
metadata:
  name: ingress-nginx
  namespace: kube-system
spec:
  type: ClusterIP
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  - name: https
    port: 443
    targetPort: 443
    protocol: TCP
  selector:
    app: ingress-nginx
---
apiVersion: v1
kind: Service
metadata:
  name: default-http-backend
  namespace: kube-system
  labels:
    app: default-http-backend
spec:
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: default-http-backend
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: default
  namespace: kube-system
spec:
  backend:
    serviceName: default-http-backend
    servicePort: 80
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration
  namespace: kube-system
  labels:
    app: ingress-nginx
data:
  use-forwarded-headers: "true"
  # 此处配置nginx日志的重定向目标
  access-log-path: /var/log/nginx_ingress_controller/access.log
  error-log-path: /var/log/nginx_ingress_controller/error.log

---

# 建立一个configmap，配置nginx日志的轮转策略，对应的是nginx日志在容器内的日志文件
apiVersion: v1
data:
  nginx.log: |
    {{ user_nginx_log.host_path }}/access.log {
        rotate {{ user_nginx_log.rotate_count }}
        daily
        maxsize {{ user_nginx_log.rotate_size }}
        minsize 10M
        copytruncate
        missingok
        create 0644 root root
    }
    {{ user_nginx_log.host_path }}/error.log {
        rotate {{ user_nginx_log.rotate_count }}
        daily
        maxsize {{ user_nginx_log.rotate_size }}
        minsize 10M
        copytruncate
        missingok
        create 0644 root root
    }
kind: ConfigMap
metadata:
  name: nginx-ingress-logrotate
  namespace: kube-system
---

kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: udp-services
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-ingress-clusterrole
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
        - events
    verbs:
        - create
        - patch
  - apiGroups:
      - "extensions"
    resources:
      - ingresses/status
    verbs:
      - update
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: nginx-ingress-role
  namespace: kube-system
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: nginx-ingress-role-nisa-binding
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: nginx-ingress-role
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: kube-system
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: ingress-nginx
  namespace: kube-system
spec:
  selector:
    matchLabels:
      app: ingress-nginx
  template:
    metadata:
      labels:
        app: ingress-nginx
      annotations:
        prometheus.io/port: '10254'
        prometheus.io/scrape: 'true'
    spec:
      serviceAccountName: nginx-ingress-serviceaccount
      tolerations:
      - key: dedicated
        value: ingress-nginx
        effect: NoSchedule
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: "system/ingress"
                operator: In
                values:
                - "true"
      dnsPolicy: ClusterFirstWithHostNet
      hostNetwork: true
      # 配置initcontainer，确保在nginx-ingress-controller容器启动前将日志目录的权限配置好
      initContainers:
      - name: adddirperm
        image: "{{ image_registry.addr }}/{{ image.adddirperm }}"
        env:
        - name: LOG_DIR
          value: /var/log/nginx_ingress_controller
        - name: USER_ID
           value: "33"
        volumeMounts:
        - name: logdir
          mountPath: /var/log/nginx_ingress_controller
      containers:
      - name: nginx-ingress-controller
        image: "{{ image_registry.addr }}/{{ image.ingress }}"
        imagePullPolicy: IfNotPresent
        args:
        - /nginx-ingress-controller
        - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
        - --configmap=$(POD_NAMESPACE)/nginx-configuration
        - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
        - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
        - --publish-service=$(POD_NAMESPACE)/ingress-nginx
        - --annotations-prefix=nginx.ingress.kubernetes.io
        
        # 设置controller日志的输出路径和方式
        - --log_dir=/var/log/nginx_ingress_controller
        - --logtostderr=false
        securityContext:
          capabilities:
              drop:
              - ALL
              add:
              - NET_BIND_SERVICE
          # www-data -> 33
          runAsUser: 33
        env:
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        ports:
        - name: http
          containerPort: 80
        - name: https
          containerPort: 443
        resources:
          requests:
            cpu: 100m
            memory: 256Mi
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          initialDelaySeconds: 10
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        volumeMounts:
        # 配置挂载容器中控制器组件和nginx的日志输出路径
        - name: logdir
          mountPath: /var/log/nginx_ingress_controller
        # 配置nginx日志的logrotate配置挂载路径
        - name: logrotateconf
          mountPath: /etc/logrotate.d/nginx.log
          subPath: nginx.log
      volumes:
      # 控制器组件和nginx的日志输出路径为宿主机的hostpath
      - name: logdir
        hostPath:
          path: {{ user_nginx_log.host_path }}
          type: ""
      # nginx日志的轮转配置文件来自于configmap
      - name: logrotateconf
        configMap:
          name: nginx-ingress-logrotate
          items:
          - key: nginx.log
            path: nginx.log
---

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: default-http-backend
  namespace: kube-system
  labels:
    app: default-http-backend
spec:
  selector:
    matchLabels:
      app: default-http-backend
  template:
    metadata:
      labels:
        app: default-http-backend
    spec:
      terminationGracePeriodSeconds: 60
      tolerations:
      - key: dedicated
        value: ingress-nginx
        effect: NoSchedule
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: "system/ingress"
                operator: In
                values:
                - "true"
      containers:
      - name: default-http-backend
        # Any image is permissible as long as:
        # 1. It serves a 404 page at /
        # 2. It serves 200 on a /healthz endpoint
        image: "{{ image_registry.addr }}/{{ image.http_backend }}"
        imagePullPolicy: IfNotPresent
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          timeoutSeconds: 5
        ports:
        - containerPort: 8080
        resources:
          limits:
            cpu: 10m
            memory: 20Mi
          requests:
            cpu: 10m
            memory: 20Mi
---

最后，有的人建议将initcontainer去掉，改成基于原有的nginx-ingress-controller镜像加一层layer，将配置路径权限的脚本放在该层执行。 我的认为这种方法既不美观，也不方便。惟一的好处仅在于deploy yaml仍然简洁（但少不了volumeMount之类的配置）。不过仍是看我的使用感觉吧~

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