mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-12-25 15:15:25 +00:00
6fab37da59
Use https: links for websites that support them. The URIs which are used as namespace identifiers are left alone. Signed-off-by: Ján Tomko <jtomko@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Neal Gompa <ngompa13@gmail.com>
294 lines
11 KiB
XML
294 lines
11 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!DOCTYPE html>
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<body>
|
|
<h1 >Remote support</h1>
|
|
<p>
|
|
Libvirt allows you to access hypervisors running on remote
|
|
machines through authenticated and encrypted connections.
|
|
</p>
|
|
<ul id="toc"></ul>
|
|
|
|
<h2>
|
|
<a id="Remote_basic_usage">Basic usage</a>
|
|
</h2>
|
|
<p>
|
|
On the remote machine, <code>libvirtd</code> should be running in general.
|
|
See <a href="#Remote_libvirtd_configuration">the section
|
|
on configuring libvirtd</a> for more information.
|
|
</p>
|
|
<p>
|
|
Not all hypervisors supported by libvirt require a running
|
|
<code>libvirtd</code>. If you want to connect to a VMware ESX/ESXi or
|
|
GSX server then <code>libvirtd</code> is not necessary. See the
|
|
<a href="drvesx.html">VMware ESX page</a> for details.
|
|
</p>
|
|
<p>
|
|
To tell libvirt that you want to access a remote resource,
|
|
you should supply a hostname in the normal <a href="uri.html">URI</a> that is passed
|
|
to <code>virConnectOpen</code> (or <code>virsh -c ...</code>).
|
|
For example, if you normally use <code>qemu:///system</code>
|
|
to access the system-wide QEMU daemon, then to access
|
|
the system-wide QEMU daemon on a remote machine called
|
|
<code>compute1.libvirt.org</code> you would use
|
|
<code>qemu://compute1.libvirt.org/system</code>.
|
|
</p>
|
|
<p>
|
|
The <a href="uri.html#URI_remote">section on remote URIs</a>
|
|
describes in more detail these remote URIs.
|
|
</p>
|
|
<p>
|
|
From an API point of view, apart from the change in URI, the
|
|
API should behave the same. For example, ordinary calls
|
|
are routed over the remote connection transparently, and
|
|
values or errors from the remote side are returned to you
|
|
as if they happened locally. Some differences you may notice:
|
|
</p>
|
|
<ul>
|
|
<li> Additional errors can be generated, specifically ones
|
|
relating to failures in the remote transport itself. </li>
|
|
<li> Remote calls are handled synchronously, so they will be
|
|
much slower than, say, direct hypervisor calls. </li>
|
|
</ul>
|
|
<h2>
|
|
<a id="Remote_transports">Transports</a>
|
|
</h2>
|
|
<p>
|
|
Remote libvirt supports a range of transports:
|
|
</p>
|
|
<dl>
|
|
<dt><code>tls</code></dt>
|
|
<dd><a href="https://en.wikipedia.org/wiki/Transport_Layer_Security" title="Transport Layer Security">TLS</a>
|
|
1.0 (SSL 3.1) authenticated and encrypted TCP/IP socket, usually
|
|
listening on a public port number. To use this you will need to
|
|
<a href="tlscerts.html" title="Generating TLS certificates">generate client and
|
|
server certificates</a>.
|
|
The standard port is 16514.
|
|
</dd>
|
|
<dt><code>unix</code></dt>
|
|
<dd> Unix domain socket. Since this is only accessible on the
|
|
local machine, it is not encrypted, and uses Unix permissions or
|
|
SELinux for authentication.
|
|
The standard socket names are
|
|
<code>/var/run/libvirt/libvirt-sock</code> and
|
|
<code>/var/run/libvirt/libvirt-sock-ro</code> (the latter
|
|
for read-only connections).
|
|
</dd>
|
|
<dt><code>ssh</code></dt>
|
|
<dd> Transported over an ordinary
|
|
<a href="https://www.openssh.com/" title="OpenSSH homepage">ssh
|
|
(secure shell)</a> connection.
|
|
Requires <a href="http://netcat.sourceforge.net/">Netcat (nc)</a>
|
|
installed and libvirtd should be running
|
|
on the remote machine. You should use some sort of
|
|
ssh key management (eg.
|
|
<a href="http://mah.everybody.org/docs/ssh" title="Using ssh-agent with ssh">ssh-agent</a>)
|
|
otherwise programs which use
|
|
this transport will stop to ask for a password. </dd>
|
|
<dt><code>ext</code></dt>
|
|
<dd> Any external program which can make a connection to the
|
|
remote machine by means outside the scope of libvirt. </dd>
|
|
<dt><code>tcp</code></dt>
|
|
<dd> Unencrypted TCP/IP socket. Not recommended for production
|
|
use, this is normally disabled, but an administrator can enable
|
|
it for testing or use over a trusted network.
|
|
The standard port is 16509. </dd>
|
|
<dt><code>libssh2</code></dt>
|
|
<dd> Transport over the SSH protocol using
|
|
<a href="https://libssh2.org/" title="libssh2 homepage">libssh2</a> instead
|
|
of the OpenSSH binary. This transport uses the libvirt authentication callback for
|
|
all ssh authentication calls and therefore supports keyboard-interactive authentication
|
|
even with graphical management applications. As with the classic ssh transport
|
|
netcat is required on the remote side.</dd>
|
|
<dt><code>libssh</code></dt>
|
|
<dd> Transport over the SSH protocol using
|
|
<a href="https://libssh.org/" title="libssh homepage">libssh</a> instead
|
|
of the OpenSSH binary. This transport uses the libvirt authentication callback for
|
|
all ssh authentication calls and therefore supports keyboard-interactive authentication
|
|
even with graphical management applications. As with the classic ssh transport
|
|
netcat is required on the remote side.</dd>
|
|
</dl>
|
|
<p>
|
|
The choice of transport is determined by the <a href="uri.html#URI_remote">URI scheme</a>,
|
|
with <code>tls</code> as the default if no explicit transport is requested.
|
|
</p>
|
|
<h2>
|
|
<a id="Remote_libvirtd_configuration">libvirtd configuration file</a>
|
|
</h2>
|
|
<p>
|
|
Libvirtd (the remote daemon) is configured from a file called
|
|
<code>/etc/libvirt/libvirtd.conf</code>, or specified on
|
|
the command line using <code>-f filename</code> or
|
|
<code>--config filename</code>.
|
|
</p>
|
|
<p>
|
|
This file should contain lines of the form below.
|
|
Blank lines and comments beginning with <code>#</code> are ignored.
|
|
</p>
|
|
<pre>setting = value</pre>
|
|
<p>The following settings, values and default are:</p>
|
|
<table class="top_table">
|
|
<tr>
|
|
<th> Line </th>
|
|
<th> Default </th>
|
|
<th> Meaning </th>
|
|
</tr>
|
|
<tr>
|
|
<td> listen_tls <i>[0|1]</i> </td>
|
|
<td> 1 (on) </td>
|
|
<td>
|
|
Listen for secure TLS connections on the public TCP/IP port.
|
|
Note: it is also necessary to start the server in listening mode by
|
|
running it with --listen or editing /etc/sysconfig/libvirtd by uncommenting the LIBVIRTD_ARGS="--listen" line
|
|
to cause the server to come up in listening mode whenever it is started.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> listen_tcp <i>[0|1]</i> </td>
|
|
<td> 0 (off) </td>
|
|
<td>
|
|
Listen for unencrypted TCP connections on the public TCP/IP port.
|
|
Note: it is also necessary to start the server in listening mode.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> tls_port <i>"service"</i> </td>
|
|
<td> "16514" </td>
|
|
<td>
|
|
The port number or service name to listen on for secure TLS connections.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> tcp_port <i>"service"</i> </td>
|
|
<td> "16509" </td>
|
|
<td>
|
|
The port number or service name to listen on for unencrypted TCP connections.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> unix_sock_group <i>"groupname"</i> </td>
|
|
<td> "root" </td>
|
|
<td>
|
|
The UNIX group to own the UNIX domain socket. If the socket permissions allow
|
|
group access, then applications running under matching group can access the
|
|
socket. Only valid if running as root
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> unix_sock_ro_perms <i>"octal-perms"</i> </td>
|
|
<td> "0777" </td>
|
|
<td>
|
|
The permissions for the UNIX domain socket for read-only client connections.
|
|
The default allows any user to monitor domains.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> unix_sock_rw_perms <i>"octal-perms"</i> </td>
|
|
<td> "0700" </td>
|
|
<td>
|
|
The permissions for the UNIX domain socket for read-write client connections.
|
|
The default allows only root to manage domains.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> tls_no_verify_certificate <i>[0|1]</i> </td>
|
|
<td> 0 (certificates are verified) </td>
|
|
<td>
|
|
If set to 1 then if a client certificate check fails, it is not an error.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> tls_no_verify_address <i>[0|1]</i> </td>
|
|
<td> 0 (addresses are verified) </td>
|
|
<td>
|
|
If set to 1 then if a client IP address check fails, it is not an error.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> key_file <i>"filename"</i> </td>
|
|
<td> "/etc/pki/libvirt/ private/serverkey.pem" </td>
|
|
<td>
|
|
Change the path used to find the server's private key.
|
|
If you set this to an empty string, then no private key is loaded.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> cert_file <i>"filename"</i> </td>
|
|
<td> "/etc/pki/libvirt/ servercert.pem" </td>
|
|
<td>
|
|
Change the path used to find the server's certificate.
|
|
If you set this to an empty string, then no certificate is loaded.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> ca_file <i>"filename"</i> </td>
|
|
<td> "/etc/pki/CA/cacert.pem" </td>
|
|
<td>
|
|
Change the path used to find the trusted CA certificate.
|
|
If you set this to an empty string, then no trusted CA certificate is loaded.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> crl_file <i>"filename"</i> </td>
|
|
<td> (no CRL file is used) </td>
|
|
<td>
|
|
Change the path used to find the CA certificate revocation list (CRL) file.
|
|
If you set this to an empty string, then no CRL is loaded.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td> tls_allowed_dn_list ["DN1", "DN2"] </td>
|
|
<td> (none - DNs are not checked) </td>
|
|
<td>
|
|
<p>
|
|
Enable an access control list of client certificate Distinguished
|
|
Names (DNs) which can connect to the TLS port on this server.
|
|
</p>
|
|
<p>
|
|
The default is that DNs are not checked.
|
|
</p>
|
|
<p>
|
|
This list may contain wildcards such as <code>"C=GB,ST=London,L=London,O=Libvirt Project,CN=*"</code>
|
|
See the POSIX <code>fnmatch</code> function for the format
|
|
of the wildcards.
|
|
</p>
|
|
<p>
|
|
Note that if this is an empty list, <i>no client can connect</i>.
|
|
</p>
|
|
<p>
|
|
Note also that GnuTLS returns DNs without spaces
|
|
after commas between the fields (and this is what we check against),
|
|
but the <code>openssl x509</code> tool shows spaces.
|
|
</p>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<h2>
|
|
<a id="Remote_IPv6">IPv6 support</a>
|
|
</h2>
|
|
<p>
|
|
The libvirtd service and libvirt remote client driver both use the
|
|
<code>getaddrinfo()</code> functions for name resolution and are
|
|
thus fully IPv6 enabled. ie, if a server has IPv6 address configured
|
|
the daemon will listen for incoming connections on both IPv4 and IPv6
|
|
protocols. If a client has an IPv6 address configured and the DNS
|
|
address resolved for a service is reachable over IPv6, then an IPv6
|
|
connection will be made, otherwise IPv4 will be used. In summary it
|
|
should just 'do the right thing(tm)'.
|
|
</p>
|
|
<h2>
|
|
<a id="Remote_limitations">Limitations</a>
|
|
</h2>
|
|
<ul>
|
|
<li> Fine-grained authentication: libvirt in general,
|
|
but in particular the remote case should support more
|
|
fine-grained authentication for operations, rather than
|
|
just read-write/read-only as at present.
|
|
</li>
|
|
</ul>
|
|
<p>
|
|
Please come and discuss these issues and more on <a href="https://www.redhat.com/mailman/listinfo/libvir-list" title="libvir-list mailing list">the mailing list</a>.
|
|
</p>
|
|
</body>
|
|
</html>
|