How to change the ssh auth method in vagrant, from password to private key?

Question

I run vagrant(1.7.2) on Mac OS(10.10.3) with Snappy Ubuntu Core(15.04 stable), for docker, using VirtualBox 4.3.28 as a provider.

I can manually ssh in the Ubuntu guest OS by a private key method in Mac terminal.

But the "vagrant ssh" command sticks to the password method, and I cannot figure out how to change the auth method.

vagrant up Bringing machine 'default' up with 'virtualbox' provider... ==> default: Checking if box 'ubuntu/ubuntu-15.04-snappy-core-stable' is up to date... ==> default: Clearing any previously set forwarded ports... ==> default: Clearing any previously set network interfaces... ==> default: Preparing network interfaces based on configuration... default: Adapter 1: nat default: Adapter 2: bridged ==> default: Forwarding ports... default: 22 => 2222 (adapter 1) ==> default: Booting VM... ==> default: Waiting for machine to boot. This may take a few minutes... default: SSH address: 192.168.0.13:2222 default: SSH username: ubuntu default: SSH auth method: password default: Warning: Connection refused. Retrying... default: Warning: Connection refused. Retrying... 

I have read through the vagrant doc about ssh settings, but found nothing "auth method" related.

And my "vagrant ssh-config" result:

vagrant ssh-config Host default HostName 192.168.0.13 User ubuntu Port 2222 UserKnownHostsFile /dev/null StrictHostKeyChecking no PasswordAuthentication no IdentityFile /Users/brady/spa/.vagrant/machines/default/virtualbox/private_key IdentitiesOnly yes LogLevel FATAL 

It shows that the password authentication is disabled, but seems like it did not work in "vagrant up"/"vagrant ssh".

And the access permission to the vagrant private key file is shown here, nothing suspicious to me.

-rw-r--r-- 1 brady staff 1.6K May 24 14:08 private_key 

Answer 1

It's probably a bug of the Ubuntu 14.04 vagrant box. link

I changed the public key on guest OS(./ssh/authorized_keys on guest VM Ubuntu 14.04) to pair with the private key on Host OS, then vagrant works like a charm.

Another solution is deleting the existing private/public key pairs in Host OS, vagrant will generated new one. Not verified.