The sentence : "Before copying the SSH public key to the target host into the user you will use in the plugin"... is bad written, sorry for the confussion.
This means that before use the plugin from pandora, you need to do a "manual" host key authentication, that means, do a ssh to destinatioin with destination user, using the same user pandora_server will use (root by default), for example:
ssh root@yourdestinationhost
Should ask something about validate the destination host. Say YES and after that, host authentication is done and plugin should work.
I'm going to update the docs to avoid more confussion in the future.
Have you check that from the pandora server (running as root) you can do this :
# ssh root@yourdestinationhost ls -la /
If that ask you something, then is wrong. It works fine, we have a problem here with the pandora server or some of parameters introduced in pandora. If that's the case, set verbosity to 10 in pandora_server,conf, restart the server and watch in detail the pandora server logs.
YES I have read ALL the documentation.
The first thing I setup was ssh auth keys!
But I do not understand 'before copying the SSH public key to the target host into the user you will use in the plugin'
What does that mean?