Vagrant fails to bring up linux clients (Authentication Failure)

[Mike C. Fletcher]

This fix:

  https://github.com/mitchellh/vagrant/commit/a6760dd8e7743e048cb2f38c474e05889356e8ac

is required for vagrant to properly bring up linux clients. Without it, vagrant is broken for the most common use cases for which it's deployed.

The bug is seen on current Yakkety releases of Vagrant (1.8.5+dfsg-2) and is a simple one-line patch that just corrects the function such that the .ssh key's permissions allow for connections. I'd suggest releasing a new upstream release, or just doing a patch so that Vagrant functionality isn't broken on Ubuntu hosts.

You can test it with this Vagrantfile:

VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = "centos/7"
  config.vm.network "public_network", type: "dhcp"
  config.vm.network :forwarded_port, guest: 22, host: 13022, id: 'ssh'
end

Under current Yakkety release that will just print:

Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'centos/7' is up to date...
==> default: Clearing any previously set network interfaces...
==> default: Available bridged network interfaces:
1) wlp2s0
2) docker0
3) tap0
==> default: When choosing an interface, it is usually the one that is
==> default: being used to connect to the internet.
    default: Which interface should the network bridge to? 1
==> default: Preparing network interfaces based on configuration...
    default: Adapter 1: nat
    default: Adapter 2: bridged
==> default: Forwarding ports...
    default: 22 (guest) => 13022 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
    default: SSH address: 127.0.0.1:13022
    default: SSH username: vagrant
    default: SSH auth method: private key
    default:
    default: Vagrant insecure key detected. Vagrant will automatically replace
    default: this with a newly generated keypair for better security.
    default:
    default: Inserting generated public key within guest...
    default: Removing insecure key from the guest if it's present...
    default: Key inserted! Disconnecting and reconnecting using new SSH key...
    default: Warning: Authentication failure. Retrying...
    default: Warning: Authentication failure. Retrying...