Installation guide

Chapter 19.
155
Remote management of virtualized
guests
This section explains how to remotely manage your virtualized guests using ssh or TLS and SSL.
19.1. Remote management with SSH
The ssh package provides an encrypted network protocol which can securely send management
functions to remote virtualization servers. The method described uses the libvirt management
connection securely tunneled over an SSH connection to manage the remote machines. All the
authentication is done using SSH public key cryptography and passwords or passphrases gathered
by your local SSH agent. In addition the VNC console for each guest virtual machine is tunneled over
SSH.
SSH is usually configured by default so you probably already have SSH keys setup and no extra
firewall rules needed to access the management service or VNC console.
Be aware of the issues with using SSH for remotely managing your virtual machines, including:
• you require root log in access to the remote machine for managing virtual machines,
• the initial connection setup process may be slow,
• there is no standard or trivial way to revoke a user's key on all hosts or guests, and
• ssh does not scale well with larger numbers of remote machines.
Configuring password less or password managed SSH access for virt-manager
The following instructions assume you are starting from scratch and do not already have SSH keys set
up. If you have SSH keys set up and copied to the other systems you can skip this procedure.
The user is important for remote management
SSH keys are user dependent. Only the user who owns the key may access that key.
virt-manager must run as the user who owns the keys to connect to the remote host. That
means, if the remote systems are managed by a non-root user virt-manager must be run in
unprivileged mode. If the remote systems are managed by the local root user then the SSH keys
must be owned and created by root.
You cannot manage the local host as an unprivileged user with virt-manager.
1. Optional: Changing user
Change user, if required. This example uses the local root user for remotely managing the other
hosts and the local host.
$ su -
2. Generating the SSH key pair
Generate a public key pair on the machine virt-manager is used. This example uses the
default key location, in the ~/.ssh/ directory.