# 使用 API Gateway 导入 API 在资源上启用 CORS
<a name="enable-cors-for-resource-using-swagger-importer-tool"></a>

如果您使用 [API Gateway 导入 API](api-gateway-import-api.md)，则可以使用 OpenAPI 文件设置 CORS 支持。您必须先在您的资源中定义可返回所需标头的 `OPTIONS` 方法。

**注意**  
Web 浏览器预计接受 CORS 请求的每个 API 方法中会设置 Access-Control-Allow 标头和 Access-Control-Allow-Origin 标头。此外，某些浏览器首先向同一资源中的 `OPTIONS` 方法发出 HTTP 请求，然后预计收到相同的标头。

## `Options` 方法示例
<a name="enable-cors-for-resource-using-swagger-importer-tool-options"></a>

以下示例创建了一个 `OPTIONS` 方法以进行模拟集成。

------
#### [ OpenAPI 3.0 ]

```
/users:
  options:
    summary: CORS support
    description: |
      Enable CORS by returning correct headers
    tags:
    - CORS
    responses:
      200:
        description: Default response for CORS method
        headers:
          Access-Control-Allow-Origin:
            schema:
              type: "string"
          Access-Control-Allow-Methods:
            schema:
              type: "string"
          Access-Control-Allow-Headers:
            schema:
              type: "string"
        content: {}
    x-amazon-apigateway-integration:
      type: mock
      requestTemplates:
        application/json: "{\"statusCode\": 200}"
      passthroughBehavior: "never"
      responses:
        default:
          statusCode: "200"
          responseParameters:
            method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
            method.response.header.Access-Control-Allow-Methods: "'*'"
            method.response.header.Access-Control-Allow-Origin: "'*'"
```

------
#### [ OpenAPI 2.0 ]

```
/users: 
   options:
      summary: CORS support
      description: |
        Enable CORS by returning correct headers
      consumes:
        - "application/json"
      produces:
        - "application/json"
      tags:
        - CORS
      x-amazon-apigateway-integration:
        type: mock
        requestTemplates: "{\"statusCode\": 200}"
        passthroughBehavior: "never"
        responses:
          "default":
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Headers : "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
              method.response.header.Access-Control-Allow-Methods : "'*'"
              method.response.header.Access-Control-Allow-Origin : "'*'"
      responses:
        200:
          description: Default response for CORS method
          headers:
            Access-Control-Allow-Headers:
              type: "string"
            Access-Control-Allow-Methods:
              type: "string"
            Access-Control-Allow-Origin:
              type: "string"
```

------

在您为资源配置 `OPTIONS` 方法后，可以将所需的标头添加到同一资源中需要接受 CORS 请求的其他方法。

1. 将 **Access-Control-Allow-Origin** 和**标头**声明为响应类型。

------
#### [ OpenAPI 3.0 ]

   ```
       responses:
         200:
           description: Default response for CORS method
           headers:
             Access-Control-Allow-Origin:
               schema:
                 type: "string"
             Access-Control-Allow-Methods:
               schema:
                 type: "string"
             Access-Control-Allow-Headers:
               schema:
                 type: "string"
           content: {}
   ```

------
#### [ OpenAPI 2.0 ]

   ```
       responses:
           200:
             description: Default response for CORS method
             headers:
               Access-Control-Allow-Headers:
                 type: "string"
               Access-Control-Allow-Methods:
                 type: "string"
               Access-Control-Allow-Origin:
                 type: "string"
   ```

------

1. 在 `x-amazon-apigateway-integration` 标签中，为这些标头设置到静态值的映射：

------
#### [ OpenAPI 3.0 ]

   ```
       responses:
           default:
             statusCode: "200"
             responseParameters:
               method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
               method.response.header.Access-Control-Allow-Methods: "'*'"
               method.response.header.Access-Control-Allow-Origin: "'*'"
             responseTemplates:
               application/json: |
                 {}
   ```

------
#### [ OpenAPI 2.0 ]

   ```
       responses:
             "default":
               statusCode: "200"
               responseParameters:
                 method.response.header.Access-Control-Allow-Headers : "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
                 method.response.header.Access-Control-Allow-Methods : "'*'"
                 method.response.header.Access-Control-Allow-Origin : "'*'"
   ```

------

## API 示例
<a name="enable-cors-for-resource-using-swagger-importer-tool-complete-example"></a>

以下示例创建一个完整的 API，其中包含一个 `OPTIONS` 方法和一个集成了 `HTTP` 的 `GET` 方法。

------
#### [ OpenAPI 3.0 ]

```
openapi: "3.0.1"
info:
  title: "cors-api"
  description: "cors-api"
  version: "2024-01-16T18:36:01Z"
servers:
- url: "/{basePath}"
  variables:
    basePath:
      default: "/test"
paths:
  /:
    get:
      operationId: "GetPet"
      responses:
        "200":
          description: "200 response"
          headers:
            Access-Control-Allow-Origin:
              schema:
                type: "string"
          content: {}
      x-amazon-apigateway-integration:
        httpMethod: "GET"
        uri: "http://petstore.execute-api.us-east-1.amazonaws.com/petstore/pets"
        responses:
          default:
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Origin: "'*'"
        passthroughBehavior: "never"
        type: "http"
    options:
      responses:
        "200":
          description: "200 response"
          headers:
            Access-Control-Allow-Origin:
              schema:
                type: "string"
            Access-Control-Allow-Methods:
              schema:
                type: "string"
            Access-Control-Allow-Headers:
              schema:
                type: "string"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Empty"
      x-amazon-apigateway-integration:
        responses:
          default:
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Methods: "'GET,OPTIONS'"
              method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
              method.response.header.Access-Control-Allow-Origin: "'*'"
        requestTemplates:
          application/json: "{\"statusCode\": 200}"
        passthroughBehavior: "never"
        type: "mock"
components:
  schemas:
    Empty:
      type: "object"
```

------
#### [  OpenAPI 2.0  ]

```
swagger: "2.0"
info:
  description: "cors-api"
  version: "2024-01-16T18:36:01Z"
  title: "cors-api"
basePath: "/test"
schemes:
- "https"
paths:
  /:
    get:
      operationId: "GetPet"
      produces:
      - "application/json"
      responses:
        "200":
          description: "200 response"
          headers:
            Access-Control-Allow-Origin:
              type: "string"
      x-amazon-apigateway-integration:
        httpMethod: "GET"
        uri: "http://petstore.execute-api.us-east-1.amazonaws.com/petstore/pets"
        responses:
          default:
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Origin: "'*'"
        passthroughBehavior: "never"
        type: "http"
    options:
      consumes:
      - "application/json"
      produces:
      - "application/json"
      responses:
        "200":
          description: "200 response"
          schema:
            $ref: "#/definitions/Empty"
          headers:
            Access-Control-Allow-Origin:
              type: "string"
            Access-Control-Allow-Methods:
              type: "string"
            Access-Control-Allow-Headers:
              type: "string"
      x-amazon-apigateway-integration:
        responses:
          default:
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Methods: "'GET,OPTIONS'"
              method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
              method.response.header.Access-Control-Allow-Origin: "'*'"
        requestTemplates:
          application/json: "{\"statusCode\": 200}"
        passthroughBehavior: "never"
        type: "mock"
definitions:
  Empty:
    type: "object"
```

------