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在本地运行AWS SAM CLI时启用CORS

aws-sam-local serverless aws-api-gateway aws-lambda amazon-web-services

Eddie Martinez · 技术社区 · 6 年前

每当我试图通过浏览器通过POST访问serverless lambda函数时,我都会得到一个错误

当它是一个 /GET POST 这就是它失败的时候。

sam local start-api

还有我的模板.yaml是:

...

Resources:
    PropertiesFunction:
        Type: AWS::Serverless::Function
        Properties:
            CodeUri: target/service-0.0.1-SNAPSHOT.jar
            Handler: com.aws.PropertiesHandler::handleRequest
            Runtime: java8
            Events:
                PropertiesApi:
                    Type: Api
                    Properties:
                        Path: /properties
                        Method: post

...

如何在这些端点上启用CORS?

1 回复 | 直到 6 年前

ngoctrambui 4 年前

为标题添加选项:

    Map<String, String> headers = new HashMap<>();
    headers.put("Content-Type", "application/json");
    headers.put("X-Custom-Header", "application/json");
    headers.put("Access-Control-Allow-Origin", "*");
    headers.put("Access-Control-Allow-Methods", "GET, POST, OPTIONS, PUT, PATCH, DELETE");
    headers.put("Access-Control-Allow-Headers", "X-Requested-With,content-type");

将选项COR添加到模板.yaml

    Globals:
      Function:
        Timeout: 20
      Api:
        Cors:
          AllowMethods: "'GET,POST,OPTIONS'"
          AllowHeaders: "'content-type'"
          AllowOrigin: "'*'"
          AllowCredentials: "'*'"

更新中的属性资源函数模板.yaml

          Events:
            HelloWorld:
              Type: Api 
              Properties:
                # Path: /hello
                # Method: get
                Path: "/{proxy+}"
                Method: ANY

user10682499 6 年前

    "Access-Control-Allow-Origin": "*"

如果在本地运行,则可以使用仅添加标头的环境变量。

下面是一个简单的Python示例,来自我拥有的处理函数:

   if not all(field in values for field in required_fields):
    response = {
        'statusCode': 400,
        'body': json.dumps(
            {
                'message': 'Required data missing from request body'
            }
        )        
    }
    # explicitly add CORs headers for local testing
    response['headers'] = {"Access-Control-Allow-Origin": "*"}
    return response

这只适用于本地测试,当您部署到API网关时,CORs由API网关上的配置处理。

这个解决方案一直对我有效,直到我还向API添加了授权,使用了Cognito用户池,我目前正在尝试解决这个问题。

How to Enable CORS for an AWS API Gateway Resource

Here's reference to it in the official AWS documentation.

me2resh 5 年前

首先,您需要在模板.yml要在API网关中启用cors:

Globals:
  Api:
    Cors:
      AllowMethods: "'GET,POST,OPTIONS'"
      AllowHeaders: "'content-type'"
      AllowOrigin: "'*'"
      AllowCredentials: "'*'"

然后在lambda函数响应中


        MultivaluedMap<String, Object> headers = responseContext.getHeaders();

        headers.add("Access-Control-Allow-Origin", "*");
        headers.add("Access-Control-Allow-Headers", requestContext.getHeaderString("Access-Control-Request-Headers"));
        headers.add("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE,HEAD,OPTIONS");