Connecting to Your Virtual Machines via SSH

!! This Method is depricated. Please request an OpenVPN account at support@osuosl.org if you do not have one !!

All the virtual machines reside on a private NAT network. In order to connect to the VMs we have setup an ssh proxy account on a jumphost which you can use to connect to hosts on the inside. In order to use the proxy with ssh, you will need to install connect-proxy.

We hope to eventually offer connections via OpenVPN, but for now this offers users with a simple approach to access.

Installing connect-proxy

For Ubuntu or Debian:

apt-get install connect-proxy

For Fedora/RH:

yum install connect-proxy

For OSX: You have two options:

  • Download the source code and compile it
  • Download a pre-built binary by us. Put this somewhere in your shell $PATH

For Windows:

  • Use the standard Cygwin installer (setup.exe) to add the connect-proxy package.
  • Every other step is the same as on Linux. This cygwin quickstart document should help you get started with Cygwin on Windows.

Configuring SSH

Next, we need to edit your ~/.ssh/config so that connecting works as expected and easily. Copy the following into your ~/ssh/config:

Host *.osuosl.test 10.20.*
ProxyCommand connect-proxy -R both -5 -S localhost:8080 %h %p

Adding SSH Keys

Now you need to add your ssh key to Ganeti Web Manager.

  1. Login into the Supercell Ganeti Web Manager site.
  2. Click on your username in the upper right hand corner
  3. Click on “Add SSH key” and copy/paste your public key

We have a cronjob that runs every five minutes which updates the keys on the jumphost so you'll need to wait on that.

Create SOCKS Proxy connection

Now we need to connect to the proxy user and setup a proxy port using the ssh client. To do that, use the following:

ssh -N -D 8080 proxy@jumphost.supercell.osuosl.org

If it works, you should see a login banner. You only need one instance of this ssh connection to connect to multiple hosts. Always remember to start this up before connecting.

[TODO: add .ssh/config to simplify this and explain backgrounding the connection]

Connect to your virtual machine

Since we have our ssh config in place, all we need to do now is try connecting to the host like any other host:

ssh root@myhostname.osuosl.test

If all goes well, it should work! If not check the steps above and ensure you have a proper ssh key deployed on your VM and in Ganeti Web Manager.

Issues connecting

If you're having issues connecting and see an error like this:

ssh_exchange_identification: Connection closed by remote host

It's likely because you had too many incorrect connection attempts and was added to the /etc/hosts.deny file via denyhosts. You will need to either contact us via IRC in #supercell or send an email to support@osuosl.org to resolve the issue. Please include your IP address so we can quickly unban you.

 
public/supercell/connecting_via_ssh.txt · Last modified: 2013/04/15 22:02 by armiller
 
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