I'm trying to configure a fi-ware cloud instance using Rex. What these instances (and probably other OpenStack-based systems) prove is a "identity file", a single private key that you can use to connect to them. I have been using variations of this:
user "root";
private_key "/home/jmerelo/.ssh/jj-iv.pem";
public_key "/home/one/public/key.dsa";
key_auth;
group fiware => "130.206.x.y";
desc "Install git";
task "git", group => "fiware", sub {
install "git";
};
where the private key is the one provided by fi-ware, and the public key is, well, whatever I thought of, or nothing. If no public key is provided, error is
[2014-11-30 11:45:45] WARN - Error running task/batch: No public_key file defined. at /home/jmerelo/perl5/perlbrew/perls/perl-5.20.0/lib/site_perl/5.20.0/Rex/Task.pm line 621.
at /home/jmerelo/perl5/perlbrew/perls/perl-5.20.0/lib/site_perl/5.20.0/Rex/TaskList/Base.pm line 273.
which is quite obviously true. But if I try other public keys, error is:
[2014-11-30 11:48:37] WARN - Error running task/batch: Wrong username/password or wrong key on 130.206.127.211. Or root is not permitted to login over SSH. at /home/jmerelo/perl5/perlbrew/perls/perl-5.20.0/lib/site_perl/5.20.0/Rex/TaskList/Base.pm line 273.
Using
ssh -i ~/.ssh/jj-iv.pem root@130.206.x.y
connects correctly to the instance. So maybe the question is "Can Rex use a single private key to connect to a host?"
Finally, I generated a public key from the private key using, as suggested by the documentation,
$ sshkey-gen -y -f /path/to/your/private.key >public.key
and then using that public.key in the Rexfile