Would someone please clarify what happens when you update a Lambda function? Do you HAVE to “Publish a new version from $LATEST”? Or will the changes be available as soon as you hit Save?
The confirmation message in the Publish dialog sounds like something I don’t want to do…
Publishing a new version saves a snapshot of the code and configuration of the $LATEST version. You can't edit the new version's code. Click to confirm.
and I’m being cautious because this is my first serious Lambda.
I have read the AWS page on versioning, but I’m still confused: https://docs.aws.amazon.com/lambda/latest/dg/versioning-intro.html
Hitting save overwrites
Once you publish a version, a copy of
$LATEST is made, and it’s assigned a new numeric version identifier. That new numbered version is frozen, immutable, and can’t be edited — but you can still always edit
Invoking the function and specifying that assigned version number (it’s on the end of the ARN) will thus always run exactly that same immutable code and associated configuration — unless you subsequently delete the version.
This is just an informational message. You aren’t going to make a mistake by publishing a new version.