I've just upgraded our EC2 plugin to the latest (1.50.2) and have found our nodes are not spinning up.

They perpetually loop with the following logs:

May 08, 2020 4:12:23 PM hudson.plugins.ec2.EC2Cloud INFO: The line with the key doesn't have the required format. Found: "ssh-ed25519 AAAAC3Nzarestofkeygoeshere ". Expected a line with this text: "ALGORITHM THEHOSTKEY", example: "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR "
 

Based on this:

https://github.com/jenkinsci/ec2-plugin/blob/master/src/main/java/hudson/plugins/ec2/ssh/verifiers/SshHostKeyVerificationStrategy.java#L139-L146, which says:

String[] parts = line.split(" ");
if (parts.length > 2) {
 

The example will never work:

{{ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJbvbEIoY3tqKwkeRW/L1FnbCLLp8a1TwSOyZHKJqFFR }}

will never split into > 2 pieces as the code says. E.g.: https://repl.it/repls/FoolishCrookedWebsite

Either I'm misunderstanding how this is meant to work, or the error message is unclear.

I've not done anything to change our configuration other than upgrading the plugin.