message: 'Missing credentials in config', inside initiateAuth(), Which credentials am I missing? - node.js

Question

I'm trying to set up rudimentary functions for user authentication in my project, but when I ask for the auth token with aws-sdk function initiateAuth() it tells me that I'm missing credentials in my config object. I've managed to set up user creation and confirmation without any credentials. Whats more is that the documentation does not make it clear that initiateAuth() requires any credentials, or which credentials it wants.
When I ask for authentication, I get this error
{ Error: connect ENETUNREACH 169.254.169.254:80
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1097:14)
message: 'Missing credentials in config',
errno: 'ENETUNREACH',
code: 'CredentialsError',
syscall: 'connect',
address: '169.254.169.254',
port: 80,
time: 2019-04-13T22:26:34.352Z,
originalError:
{ message: 'Could not load credentials from any providers',
errno: 'ENETUNREACH',
code: 'CredentialsError',
syscall: 'connect',
address: '169.254.169.254',
port: 80,
time: 2019-04-13T22:26:34.352Z,
originalError:
{ errno: 'ENETUNREACH',
code: 'ENETUNREACH',
syscall: 'connect',
address: '169.254.169.254',
port: 80,
message: 'connect ENETUNREACH 169.254.169.254:80' } } }
my code is very simple
const http = require("http")
const aws = require('aws-sdk')
const JSON5 = require('json5')
const serviceProvider = aws.CognitoIdentityServiceProvider
aws.config.update({region : 'us-east-2'})
var service = new serviceProvider()
function authorizeUser(username, password){
service.initiateAuth({
AuthFlow: 'USER_PASSWORD_AUTH',
ClientId: 'placeholder',
AuthParameters: {
'USERNAME': username,
'PASSWORD': password
},
},
function(error, data){
if(error){
console.log(error)
}
else if(data){
console.log(data)
}
})
}
Why does this function seem to ask for credentials when it shouldn't need them? If it wants credentials, which ones does it need, and how do I provide them?
EDIT: This post solved my problem. I would still appreciate an answer as to why this works however.
all I did was change one line of code.
aws.config.update({region : 'us-east-2', accessKeyId: 'anything', secretAccessKey: 'anything'})
User Pools for Amazon Cognito - CredentialsError: Missing credentials in config