centos 7: ssh asks for password

[npf]

==> server: Waiting for machine to boot. This may take a few minutes...
server: SSH address: 127.0.0.1:2222
server: SSH username: vagrant
server: SSH auth method: private key
server: Warning: Connection timeout. Retrying...
Text will be echoed in the clear. Please install the HighLine or Termios libraries to suppress echoed text.
[email protected]'s password:

once provided, boot continues...

Then new error:
In the end, /home/vagrant/.ssh does not exist...

see full logs:
https://gist.github.com/npf/0a249296ed4996b63e59

[npf]

removing `config.ssh.insert_key = false' does not change anything

[npf]

Comparing Centos7 and Centos6 boxes as imported by vagrant and before any provisioning, on Centos6, /home/vagrant/.ssh exists and authorized_keys contains the insecure vagrant key (public conterpart of $HOME/.vagrantd/insecure_private_key)... On Centos7, there is no /home/vagrant/.ssh in the box..

[npf]

As commented in #6, not setting `config.ssh.insert_key = false' in the Vagrantfile apparently makes the "secured" key inserted later in the process, but still, the unsecured key should be present beforehand, which should also fix #6 in the end.