DEV Community

Anzhari Purnomo
Anzhari Purnomo

Posted on

Parse cookie information from AWS Lambda

Recently I had a chance to work with a lot of AWS Lambda based service. I found out somehow there are not a lot of library to help extract the cookies out of lambda's request?

I ended up writing an NPM module for this issue:
https://www.npmjs.com/package/@anzp/aws-lambda-cookie

An example on how to use it:

API Gateway HTTP API Proxy Event

Consider this as your event:

{ "version": "2.0", "routeKey": "$default", "rawPath": "/path/to/resource", "rawQueryString": "parameter1=value1&parameter1=value2&parameter2=value", "cookies": [ "nevergonnagiveyouup", "nevergonna=bringyoudown; secure; httponly; samesite=strict; path=/; domain=.example.com; max-age=3600; expires=Mon, 01-Jan-2020 00:00:00 GMT; version=1; comment=something; commenturl=http://example.com/" ], "headers": { "Header1": "value1", "Header2": "value1,value2" }, "queryStringParameters": { "parameter1": "value1,value2", "parameter2": "value" }, "requestContext": { "accountId": "123456789012", "apiId": "api-id", "authentication": { "clientCert": { "clientCertPem": "CERT_CONTENT", "subjectDN": "www.example.com", "issuerDN": "Example issuer", "serialNumber": "a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1:a1", "validity": { "notBefore": "May 28 12:30:02 2019 GMT", "notAfter": "Aug 5 09:36:04 2021 GMT" } } }, "authorizer": { "jwt": { "claims": { "claim1": "value1", "claim2": "value2" }, "scopes": [ "scope1", "scope2" ] } }, "domainName": "id.execute-api.us-east-1.amazonaws.com", "domainPrefix": "id", "http": { "method": "POST", "path": "/path/to/resource", "protocol": "HTTP/1.1", "sourceIp": "192.168.0.1/32", "userAgent": "agent" }, "requestId": "id", "routeKey": "$default", "stage": "$default", "time": "12/Mar/2020:19:03:58 +0000", "timeEpoch": 1583348638390 }, "body": "eyJ0ZXN0IjoiYm9keSJ9", "pathParameters": { "parameter1": "value1" }, "isBase64Encoded": true, "stageVariables": { "stageVariable1": "value1", "stageVariable2": "value2" } }
Enter fullscreen mode Exit fullscreen mode

And this is your lambda code:

let response; const { ApiGatewayHttpApiProxyEventHandler, } = require("@anzp/aws-lambda-apig-cookie"); exports.lambdaHandler = async (event, context) => { try { const handler = new ApiGatewayHttpApiProxyEventHandler(event); const cookies = handler.getCookies(); console.log({ cookies }); response = { statusCode: 200, body: JSON.stringify({ message: JSON.stringify(cookies), // location: ret.data.trim() }), }; } catch (err) { console.log(err); return err; } return response; };
Enter fullscreen mode Exit fullscreen mode

This will be the parsed cookies:

const cookies = { cookieObjects: [ { name: "nevergonnagiveyouup", value: "" }, { name: "nevergonna", value: "bringyoudown", comment: "something", commenturl: "http://example.com/", domain: ".example.com", expires: new Date("2020-01-01T00:00:00.000Z"), httpOnly: true, maxAge: 3600, path: "/", sameSite: "strict", secure: true, version: "1", }, ], cookieStrings: [ "nevergonnagiveyouup", "nevergonna=bringyoudown; secure; httponly; samesite=strict; path=/; domain=.example.com; max-age=3600; expires=Mon, 01-Jan-2020 00:00:00 GMT; version=1; comment=something; commenturl=http://example.com/", ], };
Enter fullscreen mode Exit fullscreen mode

Cloudfront Viewer Request Event (Lambda@Edge)

Consider this as your event:

{ "Records": [ { "cf": { "config": { "distributionId": "EXAMPLE" }, "request": { "uri": "/test", "method": "GET", "clientIp": "2001:cdba::3257:9652", "headers": { "user-agent": [ { "key": "User-Agent", "value": "Test Agent" } ], "host": [ { "key": "Host", "value": "d123.cf.net" } ], "cookie": [ { "key": "Cookie", "value": "nevergonnagiveyouup" }, { "key": "Cookie", "value": "nevergonna=bringyoudown; secure; httponly; samesite=strict; path=/; domain=.example.com; max-age=3600; expires=Mon, 01-Jan-2020 00:00:00 GMT; version=1; comment=something; commenturl=http://example.com/" } ] } } } } ] }
Enter fullscreen mode Exit fullscreen mode

And this is your lambda code:

let response; const { CloudfrontViewerRequestEventHandler, } = require("@anzp/aws-lambda-apig-cookie"); exports.lambdaHandler = async (event, context, callback) => { try { const request = event.Records[0].cf.request; const handler = new CloudfrontViewerRequestEventHandler(event); const cookies = handler.getCookies(); console.log({ cookies }); } catch (err) { console.log(err); response = { statusCode: 500, }; callback(null, response) } callback(null, request) };
Enter fullscreen mode Exit fullscreen mode

This will be the parsed cookies:

const cookies = { cookieObjects: [ { name: "nevergonnagiveyouup", value: "" }, { name: "nevergonna", value: "bringyoudown", comment: "something", commenturl: "http://example.com/", domain: ".example.com", expires: new Date("2020-01-01T00:00:00.000Z"), httpOnly: true, maxAge: 3600, path: "/", sameSite: "strict", secure: true, version: "1", }, ], cookieStrings: [ "nevergonnagiveyouup", "nevergonna=bringyoudown; secure; httponly; samesite=strict; path=/; domain=.example.com; max-age=3600; expires=Mon, 01-Jan-2020 00:00:00 GMT; version=1; comment=something; commenturl=http://example.com/", ], };
Enter fullscreen mode Exit fullscreen mode

Hopefully it can help anybody struggling with the similar issue.

Top comments (0)