Cognito Lambda trigger socket timeout [duplicate] - amazon-web-services

Question

This question already has an answer here:
AWS Lambda can't call Cognito Identity - IAM Role
(1 answer)
Closed 4 years ago.
I have a Lambda trigger on my cognito resource for the presignup trigger.
I am following this example
https://docs.aws.amazon.com/cognito/latest/developerguide/user-pool-lambda-pre-sign-up.html#aws-lambda-triggers-pre-registration-example
I am getting a socket timeout and not finding much documentation on this
{
"err": {
"code": "UnexpectedLambdaException",
"name": "UnexpectedLambdaException",
"message": "arn:aws:lambda:region-arn:function:confirm failed with error Socket timeout while invoking Lambda function."
}
}
My resources are defined as so:
"ConfirmPermission" : {
"Type" : "AWS::Lambda::Permission",
"Properties" : {
"Action" : "lambda:InvokeFunction",
"FunctionName" : { "Fn::GetAtt" : [ "confirm", "Arn" ] },
"Principal" : "cognito-idp.amazonaws.com",
"SourceArn" : { "Fn::GetAtt" : [ "Auth", "Arn" ] }
}
},
"confirm" : {
"Type": "AWS::Serverless::Function",
"Properties": {
"Handler": "index.confirm",
"Runtime": "nodejs8.10",
"CodeUri": "./src",
"FunctionName": "confirm",
"ReservedConcurrentExecutions" : 15,
"Timeout": 50,
"Role": "arn:aws:iam::arn:role/lambda-vpc-role"
}
},
"AuthApp" : {
"Type" : "AWS::Cognito::UserPoolClient",
"Properties" : {
"UserPoolId" : {"Ref" : "Auth"}
}
},
"Auth" : {
"Type" : "AWS::Cognito::UserPool",
"Properties": {
"LambdaConfig" : {
"PreSignUp" : { "Fn::GetAtt" : [ "confirm", "Arn" ] }
},
"Schema" : [
{
"AttributeDataType": "String",
"Name": "email",
"Mutable": true,
"Required": true
},
{
"AttributeDataType": "String",
"Name": "family_name",
"Mutable": true,
"Required": true
},
{
"AttributeDataType": "String",
"Name": "given_name",
"Mutable": true,
"Required": true
}
],
"UsernameAttributes": ["email"]
}
}
Lambda Functions:
index.js
let signIn = require('Auth/Auth.js');
exports.signIn = signIn.signIn;
exports.signUp = signIn.signUp;
exports.confirm = signIn.confirm;
sign up / confirm
exports.signUp = async (event, context) => {
var body = JSON.parse(event.body);
var emailAttribute = {
Name : 'email',
Value: body.email
};
var firstNameAttribute = {
Name: 'given_name',
Value: body.firstName
};
var lastNameAttribute = {
Name: 'family_name',
Value: body.lastName
};
var attributeList = [emailAttribute, firstNameAttribute, lastNameAttribute];
try {
var cognitoUser = await cognitoSignUp(body, attributeList);
return {
statusCode : 200,
body : JSON.stringify({res : cognitoUser})
};
} catch(e) {
return {
statusCode : 500,
body : JSON.stringify({err : e})
};
}
}
exports.confirm = (event, context, callback) => {
event.response.autoConfirmUser = true;
callback(null, event);
return;
}
var cognitoSignUp = (body, attributeList) => new Promise((acc, rej) => {
userPool.signUp(body.email, body.password, attributeList, null, function(err, res) {
if (err) {
console.log('ERROR');
console.log(err);
rej(err);
} else {
console.log('SUCCSSS');
acc(res);
}
});
});
Any idea on what is causing this?

Answer 1

As it turns out, it's because the confirm function has an IAM role for aws resources which blocks network requests. I don't need the IAM role on this function. After removing it, it works perfectly. If you do need resource access, then you have to use a nat gateway
See more here:
AWS Lambda can't call Cognito Identity - IAM Role
https://gist.github.com/reggi/dc5f2620b7b4f515e68e46255ac042a7

Answer 2

You can increase the timeout of your function up to 15 minutes 900 seconds as shown below...
"confirm" : {
"Type": "AWS::Serverless::Function",
"Properties": {
"Handler": "index.confirm",
"Runtime": "nodejs8.10",
"CodeUri": "./src",
"FunctionName": "confirm",
"ReservedConcurrentExecutions" : 15,
"Timeout": 900,
"Role": "arn:aws:iam::arn:role/lambda-vpc-role"
}
},
Unless you're encoding something running some long analytics you probably shouldn't even need the to 50 seconds let alone 15 minutes though. you should check your logs for an error somewhere and make sure you're calling...
callback(null, event);
To return response from the Lambda.