/usr/share/doc/libvirt-doc/uri.html is in libvirt-doc 1.2.2-0ubuntu13.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 | <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<!--
This file is autogenerated from uri.html.in
Do not edit this file. Changes will be lost.
-->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<link rel="stylesheet" type="text/css" href="main.css" />
<link rel="SHORTCUT ICON" href="32favicon.png" />
<title>libvirt: Connection URIs</title>
<meta name="description" content="libvirt, virtualization, virtualization API" />
</head>
<body>
<div id="header">
<div id="headerLogo"></div>
<div id="headerSearch">
<form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><div>
<input id="query" name="query" type="text" size="12" value="" />
<input id="submit" name="submit" type="submit" value="Search" />
</div></form>
</div>
</div>
<div id="body">
<div id="menu">
<ul class="l0"><li>
<div>
<a title="Front page of the libvirt website" class="inactive" href="index.html">Home</a>
</div>
</li><li>
<div>
<a title="Details of new features and bugs fixed in each release" class="inactive" href="news.html">News</a>
</div>
</li><li>
<div>
<a title="Applications known to use libvirt" class="inactive" href="apps.html">Applications</a>
</div>
</li><li>
<div>
<a title="Get the latest source releases, binary builds and get access to the source repository" class="inactive" href="downloads.html">Downloads</a>
</div>
</li><li>
<div>
<a title="Information for users, administrators and developers" class="active" href="docs.html">Documentation</a>
<ul class="l1"><li>
<div>
<a title="How to compile libvirt" class="inactive" href="compiling.html">Compiling</a>
</div>
</li><li>
<div>
<a title="Information about deploying and using libvirt" class="active" href="deployment.html">Deployment</a>
<ul class="l2"><li>
<div>
<span class="active">URI format</span>
</div>
</li><li>
<div>
<a title="Enable remote access over TCP" class="inactive" href="remote.html">Remote access</a>
</div>
</li><li>
<div>
<a title="Configure authentication for the libvirt daemon" class="inactive" href="auth.html">Authentication</a>
</div>
</li><li>
<div>
<a title="Configure access control libvirt APIs" class="inactive" href="acl.html">Access control</a>
</div>
</li><li>
<div>
<a title="Migrating guests between machines" class="inactive" href="migration.html">Migration</a>
</div>
</li><li>
<div>
<a title="Access the libvirt daemon from a native Windows client" class="inactive" href="windows.html">Windows port</a>
</div>
</li><li>
<div>
<a title="The library and the daemon logging support" class="inactive" href="logging.html">Logging</a>
</div>
</li><li>
<div>
<a title="Audit trail logs for host operations" class="inactive" href="auditlog.html">Audit log</a>
</div>
</li><li>
<div>
<a title="Firewall and network filter configuration" class="inactive" href="firewall.html">Firewall</a>
</div>
</li><li>
<div>
<a title="Ensuring exclusive guest access to disks" class="inactive" href="locking.html">Disk locking</a>
</div>
</li><li>
<div>
<a title="Control groups integration" class="inactive" href="cgroups.html">CGroups</a>
</div>
</li><li>
<div>
<a title="Hooks for system specific management" class="inactive" href="hooks.html">Hooks</a>
</div>
</li></ul>
</div>
</li><li>
<div>
<a title="Overview of the logical subsystems in the libvirt API" class="inactive" href="intro.html">Architecture</a>
</div>
</li><li>
<div>
<a title="Description of the XML formats used in libvirt" class="inactive" href="format.html">XML format</a>
</div>
</li><li>
<div>
<a title="Hypervisor specific driver information" class="inactive" href="drivers.html">Drivers</a>
</div>
</li><li>
<div>
<a title="Reference manual for the C public API" class="inactive" href="html/index.html">API reference</a>
</div>
</li><li>
<div>
<a title="Bindings of the libvirt API for other languages" class="inactive" href="bindings.html">Language bindings</a>
</div>
</li><li>
<div>
<a title="Working on the internals of libvirt API, driver and daemon code" class="inactive" href="internals.html">Internals</a>
</div>
</li><li>
<div>
<a title="A guide and reference for developing with libvirt" class="inactive" href="devguide.html">Development Guide</a>
</div>
</li><li>
<div>
<a title="Command reference for virsh" class="inactive" href="virshcmdref.html">Virsh Commands</a>
</div>
</li><li>
<div>
<a title="Project governance and code of conduct" class="inactive" href="governance.html">Governance</a>
</div>
</li></ul>
</div>
</li><li>
<div>
<a title="User contributed content" class="inactive" href="http://wiki.libvirt.org">Wiki</a>
</div>
</li><li>
<div>
<a title="Frequently asked questions" class="inactive" href="http://wiki.libvirt.org/page/FAQ">FAQ</a>
</div>
</li><li>
<div>
<a title="How and where to report bugs and request features" class="inactive" href="bugs.html">Bug reports</a>
</div>
</li><li>
<div>
<a title="How to contact the developers via email and IRC" class="inactive" href="contact.html">Contact</a>
</div>
</li><li>
<div>
<a title="Available test suites for libvirt" class="inactive" href="testsuites.html">Test suites</a>
</div>
</li><li>
<div>
<a title="Miscellaneous links of interest related to libvirt" class="inactive" href="relatedlinks.html">Related Links</a>
</div>
</li><li>
<div>
<a title="Overview of all content on the website" class="inactive" href="sitemap.html">Sitemap</a>
</div>
</li></ul>
</div>
<div id="content">
<h1>Connection URIs</h1>
<ul><li>
<a href="#URI_libvirt">Specifying URIs to libvirt</a>
</li><li>
<a href="#URI_config">Configuring URI aliases</a>
</li><li>
<a href="#URI_default">Default URI choice</a>
</li><li>
<a href="#URI_virsh">Specifying URIs to virsh, virt-manager and virt-install</a>
</li><li>
<a href="#URI_xen">xen:/// URI</a>
</li><li>
<a href="#URI_qemu">qemu:///... QEMU and KVM URIs</a>
</li><li>
<a href="#URI_remote">Remote URIs</a>
</li><li>
<a href="#URI_test">test:///... Test URIs</a>
</li><li>
<a href="#URI_legacy">Other & legacy URI formats</a>
<ul><li>
<a href="#URI_NULL">NULL and empty string URIs</a>
</li><li>
<a href="#URI_file">File paths (xend-unix-server)</a>
</li><li>
<a href="#URI_http">Legacy: </a>
</li><li>
<a href="#URI_legacy_xen">Legacy: </a>
</li><li>
<a href="#URI_legacy_proxy">Legacy: Xen proxy</a>
</li></ul>
</li></ul>
<p>
Since libvirt supports many different kinds of virtualization
(often referred to as "drivers" or "hypervisors"), we need a
way to be able to specify which driver a connection refers to.
Additionally we may want to refer to a driver on a remote
machine over the network.
</p>
<p>
To this end, libvirt uses URIs as used on the Web and as defined in <a href="http://www.ietf.org/rfc/rfc2396.txt" shape="rect">RFC 2396</a>. This page
documents libvirt URIs.
</p>
<h2>
<a name="URI_libvirt" shape="rect" id="URI_libvirt">Specifying URIs to libvirt</a>
<a class="headerlink" href="#URI_libvirt" title="Permalink to this headline">¶</a>
</h2>
<p>
The URI is passed as the <code>name</code> parameter to <a href="html/libvirt-libvirt.html#virConnectOpen" shape="rect"><code>virConnectOpen</code></a> or <a href="html/libvirt-libvirt.html#virConnectOpenReadOnly" shape="rect"><code>virConnectOpenReadOnly</code></a>. For example:
</p>
<pre xml:space="preserve">
virConnectPtr conn = virConnectOpenReadOnly (<b>"test:///default"</b>);
</pre>
<h2>
<a name="URI_config" shape="rect" id="URI_config">Configuring URI aliases</a>
<a class="headerlink" href="#URI_config" title="Permalink to this headline">¶</a></h2>
<p>
To simplify life for administrators, it is possible to setup URI aliases in a
libvirt client configuration file. The configuration file is <code>/etc/libvirt/libvirt.conf</code>
for the root user, or <code>$XDG_CONFIG_HOME/libvirt/libvirt.conf</code> for any unprivileged user.
In this file, the following syntax can be used to setup aliases
</p>
<pre xml:space="preserve">
uri_aliases = [
"hail=qemu+ssh://root@hail.cloud.example.com/system",
"sleet=qemu+ssh://root@sleet.cloud.example.com/system",
]
</pre>
<p>
A URI alias should be a string made up from the characters
<code>a-Z, 0-9, _, -</code>. Following the <code>=</code>
can be any libvirt URI string, including arbitrary URI parameters.
URI aliases will apply to any application opening a libvirt
connection, unless it has explicitly passed the <code>VIR_CONNECT_NO_ALIASES</code>
parameter to <code>virConnectOpenAuth</code>. If the passed in
URI contains characters outside the allowed alias character
set, no alias lookup will be attempted.
</p>
<h2>
<a name="URI_default" shape="rect" id="URI_default">Default URI choice</a>
<a class="headerlink" href="#URI_default" title="Permalink to this headline">¶</a>
</h2>
<p>
If the URI passed to <code>virConnectOpen*</code> is NULL, then libvirt will use the following
logic to determine what URI to use.
</p>
<ol><li>The environment variable <code>LIBVIRT_DEFAULT_URI</code></li><li>The client configuration file <code>uri_default</code> parameter</li><li>Probe each hypervisor in turn until one that works is found</li></ol>
<h2>
<a name="URI_virsh" shape="rect" id="URI_virsh">Specifying URIs to virsh, virt-manager and virt-install</a>
<a class="headerlink" href="#URI_virsh" title="Permalink to this headline">¶</a></h2>
<p>
In virsh use the <code>-c</code> or <code>--connect</code> option:
</p>
<pre xml:space="preserve">
virsh <b>-c test:///default</b> list
</pre>
<p>
If virsh finds the environment variable
<code>VIRSH_DEFAULT_CONNECT_URI</code> set, it will try this URI by
default. Use of this environment variable is, however, deprecated
now that libvirt supports <code>LIBVIRT_DEFAULT_URI</code> itself.
</p>
<p>
When using the interactive virsh shell, you can also use the
<code>connect</code> <i>URI</i> command to reconnect to another
hypervisor.
</p>
<p>
In virt-manager use the <code>-c</code> or <code>--connect=</code><i>URI</i> option:
</p>
<pre xml:space="preserve">
virt-manager <b>-c test:///default</b>
</pre>
<p>
In virt-install use the <code>--connect=</code><i>URI</i> option:
</p>
<pre xml:space="preserve">
virt-install <b>--connect=test:///default</b> <i>[other options]</i>
</pre>
<h2>
<a name="URI_xen" shape="rect" id="URI_xen">xen:/// URI</a>
<a class="headerlink" href="#URI_xen" title="Permalink to this headline">¶</a></h2>
<p>
<i>This section describes a feature which is new in libvirt >
0.2.3. For libvirt ≤ 0.2.3 use <a href="#URI_legacy_xen" shape="rect"><code>"xen"</code></a>.</i>
</p>
<p>
To access a Xen hypervisor running on the local machine
use the URI <code>xen:///</code>.
</p>
<h2>
<a name="URI_qemu" shape="rect" id="URI_qemu">qemu:///... QEMU and KVM URIs</a>
<a class="headerlink" href="#URI_qemu" title="Permalink to this headline">¶</a></h2>
<p>
To use QEMU support in libvirt you must be running the
<code>libvirtd</code> daemon (named <code>libvirt_qemud</code>
in releases prior to 0.3.0). The purpose of this
daemon is to manage qemu instances.
</p>
<p>
The <code>libvirtd</code> daemon should be started by the
init scripts when the machine boots. It should appear as
a process <code>libvirtd --daemon</code> running as root
in the background and will handle qemu instances on behalf
of all users of the machine (among other things). </p>
<p>
So to connect to the daemon, one of two different URIs is used:
</p>
<ul><li><code>qemu:///system</code> connects to a system mode daemon. </li><li><code>qemu:///session</code> connects to a session mode daemon. </li></ul>
<p>
(If you do <code>libvirtd --help</code>, the daemon will print
out the paths of the Unix domain socket(s) that it listens on in
the various different modes).
</p>
<p>
KVM URIs are identical. You select between qemu, qemu accelerated and
KVM guests in the <a href="format.html#KVM1" shape="rect">guest XML as described
here</a>.
</p>
<h2>
<a name="URI_remote" shape="rect" id="URI_remote">Remote URIs</a>
<a class="headerlink" href="#URI_remote" title="Permalink to this headline">¶</a></h2>
<p>
Remote URIs are formed by taking ordinary local URIs and adding a
hostname and/or transport name. As a special case, using a URI
scheme of 'remote', will tell the remote libvirtd server to probe
for the optimal hypervisor driver. This is equivalent to passing
a NULL URI for a local connection. For example:
</p>
<table class="top_table"><tr><th rowspan="1" colspan="1"> Local URI </th><th rowspan="1" colspan="1"> Remote URI </th><th rowspan="1" colspan="1"> Meaning </th></tr><tr><td rowspan="1" colspan="1">
<code>xen:///</code>
</td><td rowspan="1" colspan="1">
<code>xen://oirase/</code>
</td><td rowspan="1" colspan="1"> Connect to the Xen hypervisor running on host <code>oirase</code>
using TLS. </td></tr><tr><td rowspan="1" colspan="1">
<code>NULL</code>
</td><td rowspan="1" colspan="1">
<code>remote://oirase/</code>
</td><td rowspan="1" colspan="1"> Connect to the "default" hypervisor running on host <code>oirase</code>
using TLS. </td></tr><tr><td rowspan="1" colspan="1">
<code>xen:///</code>
</td><td rowspan="1" colspan="1">
<code>xen+ssh://oirase/</code>
</td><td rowspan="1" colspan="1"> Connect to the Xen hypervisor running on host <code>oirase</code>
by going over an <code>ssh</code> connection. </td></tr><tr><td rowspan="1" colspan="1">
<code>test:///default</code>
</td><td rowspan="1" colspan="1">
<code>test+tcp://oirase/default</code>
</td><td rowspan="1" colspan="1"> Connect to the test driver on host <code>oirase</code>
using an unsecured TCP connection. </td></tr></table>
<p>
Remote URIs in libvirt offer a rich syntax and many features.
We refer you to <a href="remote.html#Remote_URI_reference" shape="rect">the libvirt
remote URI reference</a> and <a href="remote.html" shape="rect">full documentation
for libvirt remote support</a>.
</p>
<h2>
<a name="URI_test" shape="rect" id="URI_test">test:///... Test URIs</a>
<a class="headerlink" href="#URI_test" title="Permalink to this headline">¶</a></h2>
<p>
The test driver is a dummy hypervisor for test purposes.
The URIs supported are:
</p>
<ul><li><code>test:///default</code> connects to a default set of
host definitions built into the driver. </li><li><code>test:///path/to/host/definitions</code> connects to
a set of host definitions held in the named file.
</li></ul>
<h2>
<a name="URI_legacy" shape="rect" id="URI_legacy">Other & legacy URI formats</a>
<a class="headerlink" href="#URI_legacy" title="Permalink to this headline">¶</a></h2>
<h3>
<a name="URI_NULL" shape="rect" id="URI_NULL">NULL and empty string URIs</a>
<a class="headerlink" href="#URI_NULL" title="Permalink to this headline">¶</a></h3>
<p>
Libvirt allows you to pass a <code>NULL</code> pointer to
<code>virConnectOpen*</code>. Empty string (<code>""</code>) acts in
the same way. Traditionally this has meant
<q>connect to the local Xen hypervisor</q>. However in future this
may change to mean <q>connect to the best available hypervisor</q>.
</p>
<p>
The theory is that if, for example, Xen is unavailable but the
machine is running an OpenVZ kernel, then we should not try to
connect to the Xen hypervisor since that is obviously the wrong
thing to do.
</p>
<p>
In any case applications linked to libvirt can continue to pass
<code>NULL</code> as a default choice, but should always allow the
user to override the URI, either by constructing one or by allowing
the user to type a URI in directly (if that is appropriate). If your
application wishes to connect specifically to a Xen hypervisor, then
for future proofing it should choose a full <a href="#URI_xen" shape="rect"><code>xen:///</code> URI</a>.
</p>
<h3>
<a name="URI_file" shape="rect" id="URI_file">File paths (xend-unix-server)</a>
<a class="headerlink" href="#URI_file" title="Permalink to this headline">¶</a></h3>
<p>
If XenD is running and configured in <code>/etc/xen/xend-config.sxp</code>:
</p>
<pre xml:space="preserve">
(xend-unix-server yes)
</pre>
<p>
then it listens on a Unix domain socket, usually at
<code>/var/lib/xend/xend-socket</code>. You may pass a different path
using a file URI such as:
</p>
<pre xml:space="preserve">
virsh -c ///var/run/xend/xend-socket
</pre>
<h3>
<a name="URI_http" shape="rect" id="URI_http">Legacy: <code>http://...</code> (xend-http-server)</a>
<a class="headerlink" href="#URI_http" title="Permalink to this headline">¶</a></h3>
<p>
If XenD is running and configured in <code>/etc/xen/xend-config.sxp</code>:
</p>
<pre xml:space="preserve">
(xend-http-server yes)
</pre>
<p>
then it listens on TCP port 8000. libvirt allows you to
try to connect to xend running on remote machines by passing
<code>http://<i>hostname</i>[:<i>port</i>]/</code>, for example:
</p>
<pre xml:space="preserve">
virsh -c http://oirase/ list
</pre>
<p>
This method is unencrypted and insecure and is definitely not
recommended for production use. Instead use <a href="remote.html" shape="rect">libvirt's remote support</a>.
</p>
<p>
Notes:
</p>
<ol><li> The HTTP client does not fully support IPv6. </li><li> Many features do not work as expected across HTTP connections, in
particular, <a href="html/libvirt-libvirt.html#virConnectGetCapabilities" shape="rect">virConnectGetCapabilities</a>.
The <a href="remote.html" shape="rect">remote support</a> however does work
correctly. </li><li> XenD's new-style XMLRPC interface is not supported by
libvirt, only the old-style sexpr interface known in the Xen
documentation as "unix server" or "http server".</li></ol>
<h3>
<a name="URI_legacy_xen" shape="rect" id="URI_legacy_xen">Legacy: <code>"xen"</code></a>
<a class="headerlink" href="#URI_legacy_xen" title="Permalink to this headline">¶</a></h3>
<p>
Another legacy URI is to specify name as the string
<code>"xen"</code>. This will continue to refer to the Xen
hypervisor. However you should prefer a full <a href="#URI_xen" shape="rect"><code>xen:///</code> URI</a> in all future code.
</p>
<h3>
<a name="URI_legacy_proxy" shape="rect" id="URI_legacy_proxy">Legacy: Xen proxy</a>
<a class="headerlink" href="#URI_legacy_proxy" title="Permalink to this headline">¶</a></h3>
<p>
Libvirt continues to support connections to a separately running Xen
proxy daemon. This provides a way to allow non-root users to make a
safe (read-only) subset of queries to the hypervisor.
</p>
<p>
There is no specific "Xen proxy" URI. However if a Xen URI of any of
the ordinary or legacy forms is used (eg. <code>NULL</code>,
<code>""</code>, <code>"xen"</code>, ...) which fails, <i>and</i> the
user is not root, <i>and</i> the Xen proxy socket can be connected to
(<code>/tmp/libvirt_proxy_conn</code>), then libvirt will use a proxy
connection.
</p>
<p>
You should consider using <a href="remote.html" shape="rect">libvirt remote support</a>
in future. <span class="since">Since 0.8.6</span> libvirt doesn't contain
the Xen proxy anymore and you should use libvirtd instead.
</p>
</div>
</div>
<div id="footer">
<p id="sponsor">
Sponsored by:<br /><a href="http://et.redhat.com/"><img src="et.png" alt="Project sponsored by Red Hat Emerging Technology" /></a></p>
</div>
</body>
</html>
|