生成 K8s 审计日志

默认 Kubernetes 集群不会生成审计日志信息。通过以下配置，可以开启 Kubernetes 的审计日志功能。

Note

公有云环境中可能无法控制 Kubernetes 审计日志输出及输出路径。

1. 准备审计日志的 Policy 文件
2. 配置 API 服务器，开启审计日志
3. 重启并验证

准备审计日志 Policy 文件

点击查看审计日志 Policy YAML 文件

policy.yaml

apiVersion: audit.k8s.io/v1
kind: Policy
rules:
# The following requests were manually identified as high-volume and low-risk,
# so drop them.
- level: None
  users: ["system:kube-proxy"]
  verbs: ["watch"]
  resources:
   - group: "" # core
     resources: ["endpoints", "services", "services/status"]
- level: None
  # Ingress controller reads `configmaps/ingress-uid` through the unsecured port.
  # TODO(#46983): Change this to the ingress controller service account.
  users: ["system:unsecured"]
  namespaces: ["kube-system"]
  verbs: ["get"]
  resources:
   - group: "" # core
     resources: ["configmaps"]
- level: None
  users: ["kubelet"] # legacy kubelet identity
  verbs: ["get"]
  resources:
   - group: "" # core
     resources: ["nodes", "nodes/status"]
- level: None
  userGroups: ["system:nodes"]
  verbs: ["get"]
  resources:
   - group: "" # core
     resources: ["nodes", "nodes/status"]
- level: None
  users:
   - system:kube-controller-manager
   - system:kube-scheduler
   - system:serviceaccount:kube-system:endpoint-controller
     verbs: ["get", "update"]
     namespaces: ["kube-system"]
     resources:
   - group: "" # core
     resources: ["endpoints"]
- level: None
  users: ["system:apiserver"]
  verbs: ["get"]
  resources:
   - group: "" # core
     resources: ["namespaces", "namespaces/status", "namespaces/finalize"]
# Don't log HPA fetching metrics.
- level: None
  users:
   - system:kube-controller-manager
     verbs: ["get", "list"]
     resources:
   - group: "metrics.k8s.io"
# Don't log these read-only URLs.
- level: None
  nonResourceURLs:
   - /healthz*
   - /version
   - /swagger*
# Don't log events requests.
- level: None
  resources:
   - group: "" # core
     resources: ["events"]
# Secrets, ConfigMaps, TokenRequest and TokenReviews can contain sensitive & binary data,
# so only log at the Metadata level.
- level: Metadata
  resources:
   - group: "" # core
     resources: ["secrets", "configmaps", "serviceaccounts/token"]
   - group: authentication.k8s.io
     resources: ["tokenreviews"]
     omitStages:
   - "RequestReceived"
# Get responses can be large; skip them.
- level: Request
  verbs: ["get", "list", "watch"]
  resources:
   - group: "" # core
   - group: "admissionregistration.k8s.io"
   - group: "apiextensions.k8s.io"
   - group: "apiregistration.k8s.io"
   - group: "apps"
   - group: "authentication.k8s.io"
   - group: "authorization.k8s.io"
   - group: "autoscaling"
   - group: "batch"
   - group: "certificates.k8s.io"
   - group: "extensions"
   - group: "metrics.k8s.io"
   - group: "networking.k8s.io"
   - group: "policy"
   - group: "rbac.authorization.k8s.io"
   - group: "settings.k8s.io"
   - group: "storage.k8s.io"
     omitStages:
   - "RequestReceived"
# Default level for known APIs
- level: RequestResponse
  resources:
   - group: "" # core
   - group: "admissionregistration.k8s.io"
   - group: "apiextensions.k8s.io"
   - group: "apiregistration.k8s.io"
   - group: "apps"
   - group: "authentication.k8s.io"
   - group: "authorization.k8s.io"
   - group: "autoscaling"
   - group: "batch"
   - group: "certificates.k8s.io"
   - group: "extensions"
   - group: "metrics.k8s.io"
   - group: "networking.k8s.io"
   - group: "policy"
   - group: "rbac.authorization.k8s.io"
   - group: "settings.k8s.io"
   - group: "storage.k8s.io"
     omitStages:
   - "RequestReceived"
# Default level for all other requests.
- level: Metadata
  omitStages:
   - "RequestReceived"

将以上审计日志文件放到 /etc/kubernetes/audit-policy/ 文件夹下，并取名为 apiserver-audit-policy.yaml 。

配置 API 服务器

打开 API 服务器的配置文件 kube-apiserver.yaml ，一般会在 /etc/kubernetes/manifests/ 文件夹下，并添加以下配置信息：

这一步操作前请备份 kube-apiserver.yaml ，并且备份的文件不能放在 /etc/kubernetes/manifests/ 下，建议放在 /etc/kubernetes/tmp 。

1. 在 spec.containers.command 下添加命令：

   --audit-log-maxage=30
   --audit-log-maxbackup=10
   --audit-log-maxsize=100
   --audit-log-path=/var/log/audit/kube-apiserver-audit.log
   --audit-policy-file=/etc/kubernetes/audit-policy/apiserver-audit-policy.yaml
   

2. 在 spec.containers.volumeMounts 下添加：

   - mountPath: /var/log/audit
     name: audit-logs
   - mountPath: /etc/kubernetes/audit-policy
     name: audit-policy
   

3. 在 spec.volumes 下添加：

   - hostPath:
     path: /var/log/kubernetes/audit
     type: ""
     name: audit-logs
   - hostPath:
     path: /etc/kubernetes/audit-policy
     type: ""
     name: audit-policy
   

测试并验证

稍等一会，API 服务器会自动重启，执行以下命令查看 /var/log/kubernetes/audit 目录下是否有审计日志生成，若有，则表示 K8s 审计日志成功开启。

ls /var/log/kubernetes/audit

如果想关闭，去掉 spec.containers.command 中的相关命令即可。

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