Elastic Bamboo - Invalid Base64 encoding of user data

Summary

Occasionally Elastic Agent creation calls fail with the error Invalid Base64 encoding of user data

Expected Results

All elastic Agent calls succeed with creation of a new Elastic Agent

Actual Results

Occasionally the creation attempt will fail:
The below exception is thrown in the xxxxxxx.log file:

com.amazonaws.services.ec2.model.AmazonEC2Exception: Invalid BASE64 encoding of user data (Service: AmazonEC2; Status Code: 400; Error Code: InvalidParameterValue; Request ID: 24be1899-d089-48a5-b658-559d39a2034b)

Workaround

When failed, a new elastic agent call is made and the new agent starts normally.

Notes

it looks like when we use ava.util.Base64.getMimeEncoder().encodeToString(userData) to encode the userData for the instance (specifically the keypair generated per-instance) it is occasionally encoded with extra carriage returns which prevent proper decoding by AWS API.