Base64 Encoding with no new line

Occasionally when I create secrets in Kubernetes I'll get told that the credentials or values I've entered are wrong. I dig through and find everything looks OK, print out the base64 encoded secret, decode it and everything still looks OK!

What's often wrong is that there is a new line attached at the end of the string that I've encoded, so of course when it's decoded and used it's not just the string that's needed.

I usually encode things using:

echo <my string> | base64

Simple enough, but to make sure that we don't add the trailing new line use:

echo -n "<my string> | base64

That often solves my problem of invalid credentials, and I spend far too long remembering that new lines are the problem. However, it seems that not all versions of echo are the same! Sometimes the above may not work, and an alternative is to use printf which is supposedly more consistent, the same command is then applied:

printf <my string> | base64