在Lambda中解析AWS API网关标头

时间:2016-03-28 15:27:52

标签: node.js amazon-web-services aws-lambda aws-api-gateway

我已经创建了一个lambda函数和API网关端点,以便它回显它收到的查询和头参数,并且我想将整个有效负载解析为JSON以便于管理。

收到的有效载荷采用以下形式:

"{Accept=*/*, 
Accept-Encoding=gzip, 
deflate, 
Accept-Language=nb-NO,nb;q=0.8,no;q=0.6,nn;q=0.4,en-US;q=0.2,en;q=0.2,sv;q=0.2,da;q=0.2, 
Authorization=COzTjCKD6VHTC, 
Cache-Control=no-cache, 
User-Agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36, 
Via=1.1 7822a0bcea47c939c09def064206add3.cloudfront.net (CloudFront), X-Amz-Cf-Id=Bd_gFYsmhx0jK0eKf-3sZwwRozXtFoYC5UEFDDLKWYJkq6AR_L0Cfw==, 
X-Forwarded-For=89.8.222.70, 205.251.218.72, 
X-Forwarded-Port=443, X-Forwarded-Proto=https}"

手动解析这一点并不容易(字符串中没有转义)。这是什么格式,是否有一些节点库将此格式解析为JSON?

我的requestTemplate:

"requestTemplates": {
    "application/json": "{\"httpMethod\": \"$context.httpMethod\", \"route\": \"$input.params('route')\", \"query\": \"$input.params().querystring\", \"header\": \"$input.params().header\"}"
  },

2 个答案:

答案 0 :(得分:2)

如果您在API网关中使用此映射模板,它将为您解析,并在Lambda函数中以event.headers.Accept-Encodingevent.headers.Accept-Language等方式提供。

{
  "method": "$context.httpMethod",
  "body" : $input.json('$'),
  "headers": {
    #foreach($param in $input.params().header.keySet())
    "$param": "$util.escapeJavaScript($input.params().header.get($param))" #if($foreach.hasNext),#end

    #end
  },
  "queryParams": {
    #foreach($param in $input.params().querystring.keySet())
    "$param": "$util.escapeJavaScript($input.params().querystring.get($param))" #if($foreach.hasNext),#end

    #end
  },
  "pathParams": {
    #foreach($param in $input.params().path.keySet())
    "$param": "$util.escapeJavaScript($input.params().path.get($param))" #if($foreach.hasNext),#end

    #end
  },
  "stage" : "$context.stage"
}

请注意,我从kennbrodhagen对这个问题的出色答案得到了这个:How to pass a querystring or route parameter to AWS Lambda from Amazon API Gateway我刚刚添加了“stage”属性,以便在Lambda函数中使用API​​ Gateway Stage。

答案 1 :(得分:2)

您可能会发现使用 [方法请求直通] 模板(通过控制台中的生成模板下拉菜单)可以更轻松地将值转换为字典:

##  See http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html
#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"
    }
}