I'm trying to SSH into CoreOS Virtual Box using Putty. I know the username appears in the output when I do Vagrant up but I don't know what the password is.
I've also tried overriding it with config.ssh.password settings in Vagrantfile but when I do vagrant up again it comes up with Authentication failure warning and retries endlessly.
How do we use Putty to log into this Box instance?
By default there is no password set for the core user, only key-based authentication. If you'd like to set a password this can be done via cloud-config.
Place the cloud-config file in a user-data file within the cloned repository. View user-data.sample for an example.
A better method would be to follow this guide so that you can use vagrant ssh as it was designed.
By default for Vagrant:
user: vagrant
password: vagrant
..vagrant up again it comes up with Authentication failure warning and retries endlessly.
I think because it make connect with wrong ssh public key. To change it read this: https://stackoverflow.com/a/23554973/3563993
来源：https://stackoverflow.com/questions/23532693/coreos-vagrant-virtual-box-ssh-password