# k8spsphostfilesystem
#### 基本信息
- 策略类型：安全
- 推荐级别：L3
- 生效资源类型：Pod
- 参数：
  ```
  allowedHostPaths:
    readOnly: 布尔值
    pathPrefix: 字符串
  ```
  
 
#### 作用
约束PodSecurityPolicy中的"hostPath"字段的参数。
#### 策略实例示例
以下策略实例展示了策略定义生效的资源类型，parameters中的allowedHostPaths指定了字段的值。
```
apiVersion: constraints.gatekeeper.sh/v1beta1
kind: K8sPSPHostFilesystem
metadata:
  name: psp-host-filesystem
spec:
  match:
    kinds:
      - apiGroups: [""]
        kinds: ["Pod"]
  parameters:
    allowedHostPaths:
    - readOnly: true
      pathPrefix: "/foo"
```
#### 符合策略实例的资源定义
示例中hostPath中pathPrefix以/foo开头，符合策略实例。
```
apiVersion: v1
kind: Pod
metadata:
  name: nginx-host-filesystem
  labels:
    app: nginx-host-filesystem-disallowed
spec:
  containers:
    - name: nginx
      image: nginx
      volumeMounts:
        - mountPath: /cache
          name: cache-volume
          readOnly: true
  volumes:
    - name: cache-volume
      hostPath:
        path: /foo/bar
```
#### 不符合策略实例的资源定义
示例中hostPath中pathPrefix以/tmp开头，不符合策略实例。
```
apiVersion: v1
kind: Pod
metadata:
  name: nginx-host-filesystem
  labels:
    app: nginx-host-filesystem-disallowed
spec:
  containers:
  - name: nginx
    image: nginx
    volumeMounts:
    - mountPath: /cache
      name: cache-volume
      readOnly: true
  volumes:
  - name: cache-volume
    hostPath:
      path: /tmp # directory location on host
```