最近看到一篇公众号讲了nginx-ingress-controller的应用。下面有人评论如何做日志持久化，刚好工作上遇到该问题，整理一个方案，仅供参考。
nginx-ingress-controller的日志
nginx-ingress-controller的日志包括三个部分：
controller日志： 输出到stdout，通过启动参数中的 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，通过nginx-configuration中的字段可以配置输出到哪个文件。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类似。
给controller日志落盘
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/ ，
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的日志需要做定时清理。由于controller的日志是通过klog(k8s.io/klog)输出的，会进行日志滚动，所以我们通过脚本定时清理一定时间之前的日志文件即可。
给nginx日志落盘
修改configmap： nginx-configuration。配置accesslog和errorlog的输出路径，替换默认的stdout和stderr。输出路径我们可以与controller一致，便于查找。
accesslog和errorlog都只有一个日志文件，我们可以使用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：
$ 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}官方提供的模板中，nginx-ingress-controller默认都是以33这个用户登录启动容器的，因此挂载hostpath路径时存在权限问题。我们需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2、3两点均需要人工运维，有什么解决办法吗？
问题的关键是：有什么办法可以在nginx-ingress-controller容器启动之前加一个hook，将宿主机的指定目录执行chown呢？
可以用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，我们开发一个docker image，里面只执行如下脚本：
#!/bin/bashlogdir=$LOG_DIRuserID=$USER_IDecho "try to set dir: $logdir 's group as $userID"chown -R $userID:$userID $logdir
脚本读取一些环境变量， 确认需要修改哪个目录，改成怎样的user group。
将脚本打包成dockerimage， 放在nginx-ingress-controller的deploy yaml中，作为initcontainers。 注意要对该initcontainer配置环境变量和volumeMount.
再说第二点，我们注意到nginx-ingress-controller的基础镜像中就自带了logrotate，那么问题就简单了，我们将写好的logrotate配置文件以configmap的形式挂载到容器中就可以了。
一个deploy yaml如下：
---apiVersion: v1kind: Servicemetadata: name: ingress-nginx namespace: kube-systemspec: type: ClusterIP ports: - name: http port: 80 targetPort: 80 protocol: TCP - name: https port: 443 targetPort: 443 protocol: TCP selector: app: ingress-nginx---apiVersion: v1kind: Servicemetadata: name: default-http-backend namespace: kube-system labels: app: default-http-backendspec: ports: - port: 80 targetPort: 8080 selector: app: default-http-backend---apiVersion: extensions/v1beta1kind: Ingressmetadata: name: default namespace: kube-systemspec: backend: serviceName: default-http-backend servicePort: 80---kind: ConfigMapapiVersion: v1metadata: name: nginx-configuration namespace: kube-system labels: app: ingress-nginxdata: 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---# 创建一个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: v1data: 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: ConfigMapmetadata: name: nginx-ingress-logrotate namespace: kube-system---kind: ConfigMapapiVersion: v1metadata: name: tcp-services namespace: kube-system---kind: ConfigMapapiVersion: v1metadata: name: udp-services namespace: kube-system---apiVersion: v1kind: ServiceAccountmetadata: name: nginx-ingress-serviceaccount namespace: kube-system---apiVersion: rbac.authorization.k8s.io/v1beta1kind: ClusterRolemetadata: name: nginx-ingress-clusterrolerules: - 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/v1beta1kind: Rolemetadata: name: nginx-ingress-role namespace: kube-systemrules: - apiGroups: - "" resources: - configmaps - pods - secrets - namespaces verbs: - get - apiGroups: - "" resources: - configmaps resourceNames: # Defaults to "-" # Here: "-" # 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/v1beta1kind: RoleBindingmetadata: name: nginx-ingress-role-nisa-binding namespace: kube-systemroleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: nginx-ingress-rolesubjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: kube-system---apiVersion: rbac.authorization.k8s.io/v1beta1kind: ClusterRoleBindingmetadata: name: nginx-ingress-clusterrole-nisa-bindingroleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: nginx-ingress-clusterrolesubjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: kube-system---apiVersion: apps/v1kind: DaemonSetmetadata: name: ingress-nginx namespace: kube-systemspec: 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/v1kind: DaemonSetmetadata: name: default-http-backend namespace: kube-system labels: app: default-http-backendspec: 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，改为基于原有的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。 个人认为这种方法既不美观，也不方便。唯一的好处仅在于deploy yaml仍然简洁（但少不了volumeMount之类的配置）。不过还是看个人使用感受吧~