I create a user 'pandora' on the host where is the pandora agent. then i create the ssh keys (public and private).
Oops, there'is the problem, you need to create "pandora" user in the server, not in the agent. You need to generate the sshkeys in the agent for the user you will run, and copy to "pandora" user in the server.
if you could make:
ssh pandora@pandora_server
And you have a successful login in pandora_server from the agent host running the same user that agent will run, pandora_agent must be run fine.
Where is the problem. The ssh is configured correctly because I make the connectio whith the server and viceversa
Communication is only from pandora_agent -> pandora_server. You need to check
a) Existence of "pandora" user in pandora server, permissions, home directory, authorized_keys file containing pubkeys from remote user from pandora_agent.
b) Create the pubkeys in pandora_agent for the user you will run pandora_agent with.
c) Create the first ssh conection to validate ssh host key, running manually ssh pandora@pandora_server command and validate the host key.
d) Launch pandora agent :-)
I hope this helps.