如何在Lamda函数中访问呼叫者的Cognito用户名?

时间:2018-10-04 13:55:54

标签: amazon-web-services aws-lambda amazon-cognito

我已经向API网关中的API端点添加了授权。

这为事件添加了identity属性,

identity: 
{ 
    cognitoIdentityPoolId: null,
    accountId: null,
    cognitoIdentityId: null,
    caller: null,
    sourceIp: 'detracted',
    accessKey: null,
    cognitoAuthenticationType: null,
    cognitoAuthenticationProvider: null,
    userArn: null,
    userAgent: 'Amazon CloudFront',
    user: null },
    apiId: 'detracted' },
    body: null,
    isBase64Encoded: false 
}

但是那里主要是null。那么如何访问呼叫者的Cognito用户名?

编辑:

我添加了一个映射模板。但是,这是一个GET请求,因此我不知道它是否有作用,因为工具提示会说明数据已附加到主体上。

##  See http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html
##  This template will pass through all parameters including path, querystring, header, stage variables, and context through to the integration endpoint via the body/payload
#set($allParams = $input.params())
{
"body-json" : $input.json('$'),
"params" : {
#foreach($type in $allParams.keySet())
    #set($params = $allParams.get($type))
"$type" : {
    #foreach($paramName in $params.keySet())
    "$paramName" : "$util.escapeJavaScript($params.get($paramName))"
        #if($foreach.hasNext),#end
    #end
}
    #if($foreach.hasNext),#end
#end
},
"stage-variables" : {
#foreach($key in $stageVariables.keySet())
"$key" : "$util.escapeJavaScript($stageVariables.get($key))"
    #if($foreach.hasNext),#end
#end
},
"context" : {
    "account-id" : "$context.identity.accountId",
    "api-id" : "$context.apiId",
    "api-key" : "$context.identity.apiKey",
    "authorizer-principal-id" : "$context.authorizer.principalId",
    "caller" : "$context.identity.caller",
    "cognito-authentication-provider" : "$context.identity.cognitoAuthenticationProvider",
    "cognito-authentication-type" : "$context.identity.cognitoAuthenticationType",
    "cognito-identity-id" : "$context.identity.cognitoIdentityId",
    "cognito-identity-pool-id" : "$context.identity.cognitoIdentityPoolId",
    "http-method" : "$context.httpMethod",
    "stage" : "$context.stage",
    "source-ip" : "$context.identity.sourceIp",
    "user" : "$context.identity.user",
    "user-agent" : "$context.identity.userAgent",
    "user-arn" : "$context.identity.userArn",
    "request-id" : "$context.requestId",
    "resource-id" : "$context.resourceId",
    "resource-path" : "$context.resourcePath",
    "username" : "$context.authorizer.claims['cognito:username']"
    }
}
"event" : {
    "username" : "$context.authorizer.claims['cognito:username']"
}

1 个答案:

答案 0 :(得分:1)

您要通过调用API Gateway发送用户的idToken,对吧?

我认为您已经在此解决方案中成功获取了用户的Cognito信息。

在对API Gateway的调用中,您包括带有令牌的Authorization标头,如下所示:

var url = YOURURL;
var options = {
    method: "GET",
    headers: {
        'Authorization': COGNITOUSER_IDTOKEN
    }
}

fetch(url, options);

有很多方法可以获取用户的ID令牌,因此我在这里不作规定。

只要这样做,就可以通过集成请求(API网关中API阶段中的)映射模板访问令牌中的信息。

在映射模板中,您可以使用以下代码:

{
  "username" : "$context.authorizer.claims['cognito:username']"
}

然后,您可以在Lambda函数中通过引用“ event.username”来访问它。