应用开放策略代理 (OPA) 策略

应用开放策略代理 (OPA) 策略

使用中间件对传入的请求应用开放策略代理（OPA）策略。

The Open Policy Agent (OPA) HTTP middleware applys OPA Policies to incoming Dapr HTTP requests. 这可以用来将可重用的授权策略应用到应用终结点。

配置

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: my-policy
  namespace: default
spec:
  type: middleware.http.opa
  version: v1
  metadata:
    # `includedHeaders` is a comma-separated set of case-insensitive headers to include in the request input.
    # Request headers are not passed to the policy by default. Include to receive incoming request headers in
    # the input
    - name: includedHeaders
      value: "x-my-custom-header, x-jwt-header"
    # `defaultStatus` is the status code to return for denied responses
    - name: defaultStatus
      value: 403
    # `rego` is the open policy agent policy to evaluate. required
    # The policy package must be http and the policy must set data.http.allow
    - name: rego
      value: |
        package http
        default allow = true
        # Allow may also be an object and include other properties
        # For example, if you wanted to redirect on a policy failure, you could set the status code to 301 and set the location header on the response:
        allow = {
            "status_code": 301,
            "additional_headers": {
                "location": "https://my.site/authorize"
            }
        } {
            not jwt.payload["my-claim"]
        }
        # You can also allow the request and add additional headers to it:
        allow = {
            "allow": true,
            "additional_headers": {
                "x-my-claim": my_claim
            }
        } {
            my_claim := jwt.payload["my-claim"]
        }
        jwt = { "payload": payload } {
            auth_header := input.request.headers["authorization"]
            [_, jwt] := split(auth_header, " ")
            [_, payload, _] := io.jwt.decode(jwt)
        }

您可以使用官方 opa playground对策略进行原型设计和实验。例如，您可以在这里找到上面的示例策略。

元数据字段规范

字段	详情	Example
rego	Rego策略语言	见上文
defaultStatus	状态码返回拒绝的响应	`“https://accounts.google.com“`, `“https://login.salesforce.com“`
includedHeaders	一组以逗号分隔的不区分大小写的头信息，包含在请求输入中。默认情况下，请求头不会传递给策略。在输入中包含接收传入的请求头。	`“x-my-custom-header, x-jwt-header”`

Dapr配置

To be applied, the middleware must be referenced in configuration. See middleware pipelines.

apiVersion: dapr.io/v1alpha1
kind: Configuration
metadata:
  name: appconfig
spec:
  httpPipeline:
    handlers:
    - name: my-policy
      type: middleware.http.opa

输入

这个中间件提供了一个 HTTPRequest 作为输入。

HTTP请求

HTTPRequest 输入包含所有关于传入HTTP请求的透彻信息，但它的正文除外。

type Input struct {
  request HTTPRequest
}
type HTTPRequest struct {
  // The request method (e.g. GET,POST,etc...)
  method string
  // The raw request path (e.g. "/v2/my-path/")
  path string
  // The path broken down into parts for easy consumption (e.g. ["v2", "my-path"])
  path_parts string[]
  // The raw query string (e.g. "?a=1&b=2")
  raw_query string
  // The query broken down into keys and their values
  query map[string][]string
  // The request headers
  // NOTE: By default, no headers are included. You must specify what headers
  // you want to receive via `spec.metadata.includedHeaders` (see above)
  headers map[string]string
  // The request scheme (e.g. http, https)
  scheme string
}
  method string
  // The raw request path (e.g. "/v2/my-path/")
  path string
  // The path broken down into parts for easy consumption (e.g. ["v2", "my-path"])
  path_parts string[]
  // The raw query string (e.g. "?a=1&b=2")
  raw_query string
  // The query broken down into keys and their values
  query map[string][]string
  // The request headers
  // NOTE: By default, no headers are included. You must specify what headers
  // you want to receive via `spec.metadata.includedHeaders` (see above)
  headers map[string]string
  // The request scheme (e.g. http, https)
  scheme string
}

结果

策略必须设置 data.http.allow 带有 boolean 值或者一个 object 值与一个 allow 布尔属性。 true allow 将允许请求当一个 false 值将以 defaultStatus 指定的状态拒绝请求。下面的策略，在默认情况下，演示了对所有请求的 403 - Forbidden:

package http
default allow = false

等价于：

package http
default allow = {
  "allow": false
}

更改拒绝的响应状态代码

拒绝请求时，您可以覆盖返回的状态代码。例如，如果您想退回 401 而不是 403，你可以这样做：

package http
default allow = {
  "allow": false,
  "status_code": 401
}

添加响应头

若要重定向，添加消息头并将 status_code 设置为返回的结果：

package http
default allow = {
  "allow": false,
  "status_code": 301,
  "additional_headers": {
    "Location": "https://my.redirect.site"
  }
}

添加请求头

你也可以在允许的请求上设置额外的头信息：

package http
default allow = false
allow = { "allow": true, "additional_headers": { "X-JWT-Payload": payload } } {
  not input.path[0] == "forbidden"
  // Where `jwt` is the result of another rule
  payload := base64.encode(json.marshal(jwt.payload))
}

结果结构

type Result bool
// or
type Result struct {
  // Whether to allow or deny the incoming request
  allow bool
  // Overrides denied response status code; Optional
  status_code int
  // Sets headers on allowed request or denied response; Optional
  additional_headers map[string]string
}

开放策略代理 (OPA)