Home / ubuntu / Questions / 324574
Accepted
Moshe Katz
Asked: 2013-07-26 11:39:36 +0800 CST

Cannot ssh into new Vagrant install of 13.04

  • 772

I used the Vagrant image for 13.04 from http://cloud-images.ubuntu.com/vagrant/raring/current/raring-server-cloudimg-i386-vagrant-disk1.box to create a new virtual machine and tried to connect to it using ssh. However, the SSH always disconnected immediately, without even getting to the stage where it tried to authenticate.

I opened the VM in the VirtualBox GUI and looked at the SSH log file (auth.log). It was full of lines like this:

Jul 25 17:57:02 vagrant-ubuntu-raring-32 sshd[898]: error: Could not load host key: /etc/ssh/ssh_host_rsa_key
Jul 25 17:57:02 vagrant-ubuntu-raring-32 sshd[898]: error: Could not load host key: /etc/ssh/ssh_host_dsa_key
Jul 25 17:57:02 vagrant-ubuntu-raring-32 sshd[898]: error: Could not load host key: /etc/ssh/ssh_host_ecdsa_key
Jul 25 17:57:02 vagrant-ubuntu-raring-32 sshd[898]: fatal: No supported key exchange algorithms [preauth]

The problem was solved by executing the following commands:

sudo ssh-keygen -f /etc/ssh/ssh_host_ecdsa_key -N '' -t ecdsa
sudo ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa
sudo ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa

I would assume that these should run automatically at some point, especially given that (a) I did not have to run them myself when I installed Ubuntu from an ISO image, and (b) because Vagrant is supposed to be designed that after you run vagrant up you can immediately use the VM without any additional configuration.

I may need to create a large number of Virtual Machines in the near future and I was hoping that I could use Vagrant to do it, but I can't do it if I'm going to have to manually fix SSH on each one.

Does anyone know why this happens and what can be done to fix it? Should I report it as a bug?

ssh

3 Answers

  1. This is SSH host key problem (NOT related to public key authentication).

    Looks like the problem was that the ubuntu cloud vagrant image failed to generate the new host keys (if they are not there in /etc/ssh/) during the 1st boot (vagrant up).

    In addition to manually generate the SSH host keys mentioned by Moshe

    sudo ssh-keygen -f /etc/ssh/ssh_host_ecdsa_key -N '' -t ecdsa
sudo ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa
sudo ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa

    It can also be done by adding the following command in the /etc/rc.local

    test -f /etc/ssh/ssh_host_dsa_key || dpkg-reconfigure openssh-server

    Hope it helps.

    • 5

  2. Workaroud:

    • Import ~/.vagrant.d/boxes/raring/box.ovf appliance in VirtualBox

      VBoxManage import ~/.vagrant.d/boxes/raring/box.ovf

    • Get VM Name

      VBoxManage list vms

    • Start the VM

      VBoxManage startvm ubuntu-cloudimg-raring-vagrant-amd64

    • Include the following line in /etc/rc.local (Of course in the VM itself!):

      test -f /etc/ssh/ssh_host_dsa_key || dpkg-reconfigure openssh-server

    • Shutdown VM

      sudo halt

    • Delete old images

      rm ~/.vagrant.d/boxes/raring/box.ovf ~/.vagrant.d/boxes/raring/box-disk1.vmdk

    • Export VM in .ovf format

      VBoxManage export ubuntu-cloudimg-raring-vagrant-amd64 --output ~/.vagrant.d/boxes/raring/box.ovf

    Done :)

    Did also an bugreport: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1217950

    • 5
  3. Best Answer

    This appears to have been a bug in the older base boxes. In the current base box images (generated August 20th, 2013), the keys appear to be created automatically when the box boots up for the first time.

    • 3