Update Route53 record using lambda nodejs not working - amazon-web-services

Question

I am trying to update a record in Route53 using a lambda function and nodejs runtime.
The problem is I am getting no errors, no logs or anything from route53 to even understand why it is not working.
I have setup the following:
Lambda function
SNS to read messages from
Attached a policy to update/change record sets
My lambda code:
console.log('Running updateRecordSet');
/* global HOSTED_ZONE_ID*/
/* global DNS_RECORD_NAME*/
HOSTED_ZONE_ID = 'xxxx';
DNS_RECORD_NAME = 'dns-record.internal.example.com.';
var aws = require('aws-sdk');
var route53 = new aws.Route53();
exports.handler = async (event, context) => {
const message = event.Records[0].Sns.Message;
console.log('SNS message:', message);
try {
const data = JSON.parse(message);
if (data.ip) {
console.log('New IP: ', data.ip);
var newRecord = {
HostedZoneId: HOSTED_ZONE_ID,
ChangeBatch: {
Changes: [{
Action: 'UPSERT',
ResourceRecordSet: {
Name: DNS_RECORD_NAME,
Type: 'A',
ResourceRecords: [{Value: data.ip}],
TTL: 30,
}
}]
}
};
updateRecordSet(route53, DNS_RECORD_NAME, HOSTED_ZONE_ID, newRecord, function(err) {
if (err) {
return context.fail(err);
}
return context.succeed('OK');
});
}
} catch(err) {
console.error(err);
}
return message;
};
function updateRecordSet(route53, DNS_RECORD_NAME, HOSTED_ZONE_ID, newRecord, callback) {
console.log("Executing function updateRecordSet");
route53.changeResourceRecordSets(newRecord, function(err) {
if (err) {
console.log("Got an err");
return callback(err);
}
return console.log('Updated A record for', DNS_RECORD_NAME);
});
}
I get the output:
Function Logs:
START RequestId: 4ef801ba-c03c-4582-33a8-c078c46f0b03 Version: $LATEST
2019-04-07T04:18:55.201Z 4ef801ba-c03c-4582-83a8-c078c46f0b03 SNS message: {"ip": "10.1.1.1"}
2019-04-07T04:18:55.201Z 4ef801ba-c03c-4582-83a8-c078c46f0b03 New IP: 10.1.1.1
2019-04-07T04:18:55.201Z 4ef801ba-c03c-4582-83a8-c078c46f0b03 Executing function updateRecordSet
END RequestId: 4ef801ba-c03c-4582-33a8-c078c46f0b03
If the IAM policy is wrong I would at least get some kind of authentication error?

Answer 1

I could not get async to work with lambda for some reason but finally got working code.
This lambda will update or insert a record set in Route53 reading from SNS with a JSON message like {"ip": "10.1.1.1"}
console.log('Running updateRecordSet');
var AWS = require('aws-sdk');
/* global HOSTED_ZONE_ID*/
/* global DNS_RECORD_NAME*/
HOSTED_ZONE_ID = 'xxxxxx';
DNS_RECORD_NAME = 'dns-record.example.com.';
exports.handler = function(event, context, callback) {
var route53 = new AWS.Route53();
// Get message from SNS
var message = event.Records[0].Sns.Message;
const data = JSON.parse(message);
if (typeof data.ip !== "undefined") {
route53.changeResourceRecordSets({
HostedZoneId : HOSTED_ZONE_ID,
ChangeBatch : {
Changes : [{
Action: 'UPSERT',
ResourceRecordSet: {
Name: DNS_RECORD_NAME,
Type: 'A',
ResourceRecords: [
{
Value: data.ip
}
],
TTL: 30
}
}]
}
}, function (err, data) {
if (err)
console.log(err, err.stack);
else {
console.log('Updated Route53 DNS record ' + DNS_RECORD_NAME);
}
});
} else {
console.log('No IP found in message. Discarding.');
}
};

Answer 2

If you want to have full promise and await thing setup, you can try the below code. It has a few additional things like STS assume-role for cross-account ROUTE53 access. Additionally, it has a weighted logic to create multiple CNAMEs. I understand this does not fit your use case, however it may help somebody who stumbles upon a similar issue to create Weighted load balancing with CNAME.
console.log('Running route53 changeRecrodSet with CNAME');
/* global HOSTED_ZONE_ID*/
/* global DNS_RECORD_NAME*/
const HOSTED_ZONE_ID = "xxxx";
const DNS_RECORD_NAME = "xxxxxx.com";
var AWS = require('aws-sdk');
AWS.config.region = 'us-west-1';
async function update_recordset(route53, records){
return route53.changeResourceRecordSets(records).promise();
}
async function getcred(){
console.log("inside getcred");
var sts = new AWS.STS();
try {
let temp_cred = sts.assumeRole({
RoleArn: 'arn:aws:iam::xxxxxxxx',
RoleSessionName: 'awssdk'
}).promise();
console.log("TEMP",temp_cred);
return temp_cred;
}catch(err){
console.log("ERROR",err);
}
}
exports.handler = async (event) => {
const message = event.Records[0].Sns.Message;
console.log('SNS message:', message);
try{
const data = JSON.parse(message);
if (data.cname) {
console.log('New IP: ', data.cname);
const sts_result = await getcred();
console.log("STS_RESULT", sts_result);
AWS.config.update({
accessKeyId: sts_result.Credentials.AccessKeyId,
secretAccessKey: sts_result.Credentials.SecretAccessKey,
sessionToken: sts_result.Credentials.SessionToken
});
var route53 = new AWS.Route53();
console.log("ROUTE53 RESULT",route53);
const newRecord = {
HostedZoneId: HOSTED_ZONE_ID,
ChangeBatch: {
Changes: [
{
Action: 'UPSERT',
ResourceRecordSet: {
SetIdentifier: "elb",
Weight: 100,
Name: DNS_RECORD_NAME,
Type: 'CNAME',
ResourceRecords: [{ Value: "xxxxx.sxxxxx.com" }],
TTL: 300,
},
},
{
Action: 'UPSERT',
ResourceRecordSet: {
SetIdentifier: "cflare",
Weight: 100,
Name: DNS_RECORD_NAME,
Type: 'CNAME',
ResourceRecords: [{ Value: data.cname }],
TTL: 300,
},
}],
},
};
const results = await update_recordset(route53,newRecord);
console.log("Result", results);
}
}catch(err){
console.log("ERR",err);
}
};

Answer 3

You need to either put an async - await or just callback(). Both it is a bad practice.
I would do something like this:
console.log('Running updateRecordSet');
/* global HOSTED_ZONE_ID*/
/* global DNS_RECORD_NAME*/
HOSTED_ZONE_ID = 'xxxx';
DNS_RECORD_NAME = 'dns-record.internal.example.com.';
var aws = require('aws-sdk');
var route53 = new aws.Route53();
exports.handler = async (event) => {
const message = event.Records[0].Sns.Message;
console.log('SNS message:', message);
try {
const data = JSON.parse(message);
if (data.ip) {
console.log('New IP: ', data.ip);
var newRecord = {
HostedZoneId: HOSTED_ZONE_ID,
ChangeBatch: {
Changes: [{
Action: 'UPSERT',
ResourceRecordSet: {
Name: DNS_RECORD_NAME,
Type: 'A',
ResourceRecords: [{Value: data.ip}],
TTL: 30,
}
}]
}
};
let result = await route53.changeResourceRecordSets(newRecord);
console.log(result);
}
} catch(err) {
console.error(err);
}
return message;
};
Also you are right about the iam role, you will get an autherization error if your code runs all the functions correctly.

Answer 4

To get async/await to work with AWS sdk, you need promisify.
See example below...
console.log('Running updateRecordSet');
/* global HOSTED_ZONE_ID*/
/* global DNS_RECORD_NAME*/
HOSTED_ZONE_ID = 'xxxx';
DNS_RECORD_NAME = 'dns-record.internal.example.com.';
const aws = require('aws-sdk');
const route53 = new aws.Route53();
const { promisify } = require('util');
const changeResourceRecordSets = promisify(route53.changeResourceRecordSets.bind(route53));
exports.handler = async (event) => {
const message = event.Records[0].Sns.Message;
console.log('SNS message:', message);
try {
const data = JSON.parse(message);
if (data.ip) {
console.log('New IP: ', data.ip);
const newRecord = {
HostedZoneId: HOSTED_ZONE_ID,
ChangeBatch: {
Changes: [
{
Action: 'UPSERT',
ResourceRecordSet: {
Name: DNS_RECORD_NAME,
Type: 'A',
ResourceRecords: [{ Value: data.ip }],
TTL: 30,
},
}],
},
};
const results = await changeResourceRecordSets(newRecord);
if (results.ChangeInfo.Status === 'PENDING') {
console.log('Updated A record for', DNS_RECORD_NAME, results);
return {
statusCode: 200,
body: 'Success',
};
} else {
console.error(results);
return {
statusCode: 500,
body: 'Something went wrong',
};
}
}
} catch (err) {
console.error(err);
}
};