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docs: html.in: Convert aclpolkit to rst
Signed-off-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com>
This commit is contained in:
Erik Skultety
parent
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html>
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<html xmlns="http://www.w3.org/1999/xhtml">
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<body>
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<h1>Polkit access control</h1>
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<p>
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Libvirt's client <a href="acl.html">access control framework</a> allows
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administrators to setup fine grained permission rules across client users,
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managed objects and API operations. This allows client connections
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to be locked down to a minimal set of privileges. The polkit driver
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provides a simple implementation of the access control framework.
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</p>
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<ul id="toc"></ul>
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<h2><a id="intro">Introduction</a></h2>
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<p>
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A default install of libvirt will typically use
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<a href="https://www.freedesktop.org/wiki/Software/polkit/">polkit</a>
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to authenticate the initial user connection to libvirtd. This is a
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very coarse grained check though, either allowing full read-write
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access to all APIs, or just read-only access. The polkit access
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control driver in libvirt builds on this capability to allow for
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fine grained control over the operations a user may perform on an
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object.
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</p>
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<h2><a id="perms">Permission names</a></h2>
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<p>
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The libvirt <a href="acl.html#perms">object names and permission names</a>
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are mapped onto polkit action names using the simple pattern:
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</p>
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<pre>org.libvirt.api.$object.$permission
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</pre>
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<p>
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The only caveat is that any underscore characters in the
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object or permission names are converted to hyphens. So,
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for example, the <code>search_storage_vols</code> permission
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on the <code>storage_pool</code> object maps to the polkit
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action:
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</p>
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<pre>org.libvirt.api.storage-pool.search-storage-vols
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</pre>
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<p>
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The default policy for any permission which corresponds to
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a "read only" operation, is to allow access. All other
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permissions default to deny access.
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</p>
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<h2><a id="attrs">Object identity attributes</a></h2>
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<p>
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To allow polkit authorization rules to be written to match
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against individual object instances, libvirt provides a number
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of authorization detail attributes when performing a permission
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check. The set of attributes varies according to the type
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of object being checked
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</p>
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<h3><a id="object_connect">virConnectPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_domain">virDomainPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>domain_name</td>
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<td>Name of the domain, unique to the local host</td>
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</tr>
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<tr>
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<td>domain_uuid</td>
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<td>UUID of the domain, globally unique</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_interface">virInterfacePtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>interface_name</td>
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<td>Name of the network interface, unique to the local host</td>
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</tr>
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<tr>
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<td>interface_macaddr</td>
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<td>MAC address of the network interface, not unique</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_network">virNetworkPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>network_name</td>
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<td>Name of the network, unique to the local host</td>
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</tr>
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<tr>
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<td>network_uuid</td>
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<td>UUID of the network, globally unique</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_node_device">virNodeDevicePtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>node_device_name</td>
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<td>Name of the node device, unique to the local host</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_nwfilter">virNWFilterPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>nwfilter_name</td>
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<td>Name of the network filter, unique to the local host</td>
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</tr>
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<tr>
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<td>nwfilter_uuid</td>
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<td>UUID of the network filter, globally unique</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_secret">virSecretPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>secret_uuid</td>
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<td>UUID of the secret, globally unique</td>
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</tr>
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<tr>
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<td>secret_usage_volume</td>
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<td>Name of the associated volume, if any</td>
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</tr>
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<tr>
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<td>secret_usage_ceph</td>
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<td>Name of the associated Ceph server, if any</td>
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</tr>
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<tr>
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<td>secret_usage_target</td>
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<td>Name of the associated iSCSI target, if any</td>
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</tr>
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<tr>
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<td>secret_usage_name</td>
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<td>Name of the associated TLS secret, if any</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_storage_pool">virStoragePoolPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>pool_name</td>
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<td>Name of the storage pool, unique to the local host</td>
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</tr>
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<tr>
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<td>pool_uuid</td>
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<td>UUID of the storage pool, globally unique</td>
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</tr>
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</tbody>
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</table>
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<h3><a id="object_storage_vol">virStorageVolPtr</a></h3>
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<table>
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<thead>
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<tr>
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<th>Attribute</th>
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<th>Description</th>
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</tr>
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</thead>
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<tbody>
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<tr>
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<td>connect_driver</td>
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<td>Name of the libvirt connection driver</td>
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</tr>
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<tr>
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<td>pool_name</td>
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<td>Name of the storage pool, unique to the local host</td>
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</tr>
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<tr>
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<td>pool_uuid</td>
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<td>UUID of the storage pool, globally unique</td>
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</tr>
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<tr>
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<td>vol_name</td>
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<td>Name of the storage volume, unique to the pool</td>
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</tr>
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<tr>
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<td>vol_key</td>
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<td>Key of the storage volume, globally unique</td>
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</tr>
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</tbody>
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</table>
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<h2><a id="connect_driver">Hypervisor Driver connect_driver</a></h2>
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<p>
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The <code>connect_driver</code> parameter describes the
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client's <a href="remote.html">remote Connection Driver</a>
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name based on the <a href="uri.html">URI</a> used for the
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connection.
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</p>
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<p>
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<span class="since">Since 4.1.0</span>, when calling an API
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outside the scope of the primary connection driver, the
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primary driver will attempt to open a secondary connection
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to the specific API driver in order to process the API. For
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example, when hypervisor domain processing needs to make an
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API call within the storage driver or the network filter driver
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an attempt to open a connection to the "storage" or "nwfilter"
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driver will be made. Similarly, a "storage" primary connection
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may need to create a connection to the "secret" driver in order
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to process secrets for the API. If successful, then calls to
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those API's will occur in the <code>connect_driver</code> context
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of the secondary connection driver rather than in the context of
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the primary driver. This affects the <code>connect_driver</code>
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returned from rule generation from the <code>action.loookup</code>
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function. The following table provides a list of the various
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connection drivers and the <code>connect_driver</code> name
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used by each regardless of primary or secondary connection.
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The access denied error message from libvirt will list the
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connection driver by name that denied the access.
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</p>
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<h3><a id="object_connect_driver">Connection Driver Name</a></h3>
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<table>
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<thead>
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<tr>
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<th>Connection Driver</th>
|
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<th><code>connect_driver</code> name</th>
|
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</tr>
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||||
</thead>
|
||||
<tbody>
|
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<tr>
|
||||
<td>bhyve</td>
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<td>bhyve</td>
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</tr>
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<tr>
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<td>esx</td>
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<td>ESX</td>
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</tr>
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<tr>
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<td>hyperv</td>
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<td>Hyper-V</td>
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</tr>
|
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<tr>
|
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<td>interface</td>
|
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<td>interface</td>
|
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</tr>
|
||||
<tr>
|
||||
<td>xen</td>
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<td>Xen</td>
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</tr>
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<tr>
|
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<td>lxc</td>
|
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<td>LXC</td>
|
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</tr>
|
||||
<tr>
|
||||
<td>network</td>
|
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<td>network</td>
|
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</tr>
|
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<tr>
|
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<td>nodedev</td>
|
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<td>nodedev</td>
|
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</tr>
|
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<tr>
|
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<td>nwfilter</td>
|
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<td>NWFilter</td>
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</tr>
|
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<tr>
|
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<td>openvz</td>
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<td>OPENVZ</td>
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</tr>
|
||||
<tr>
|
||||
<td>qemu</td>
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<td>QEMU</td>
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</tr>
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<tr>
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<td>secret</td>
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<td>secret</td>
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</tr>
|
||||
<tr>
|
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<td>storage</td>
|
||||
<td>storage</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>vbox</td>
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<td>VBOX</td>
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</tr>
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<tr>
|
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<td>vmware</td>
|
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<td>VMWARE</td>
|
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</tr>
|
||||
<tr>
|
||||
<td>vz</td>
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<td>vz</td>
|
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</tr>
|
||||
</tbody>
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||||
</table>
|
||||
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||||
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<h2><a id="user">User identity attributes</a></h2>
|
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|
||||
<p>
|
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At this point in time, the only attribute provided by
|
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libvirt to identify the user invoking the operation
|
||||
is the PID of the client program. This means that the
|
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polkit access control driver is only useful if connections
|
||||
to libvirt are restricted to its UNIX domain socket. If
|
||||
connections are being made to a TCP socket, no identifying
|
||||
information is available and access will be denied.
|
||||
Also note that if the client is connecting via an SSH
|
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tunnel, it is the local SSH user that will be identified.
|
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In future versions, it is expected that more information
|
||||
about the client user will be provided, including the
|
||||
SASL / Kerberos username and/or x509 distinguished
|
||||
name obtained from the authentication provider in use.
|
||||
</p>
|
||||
|
||||
|
||||
<h2><a id="checks">Writing access control policies</a></h2>
|
||||
|
||||
<p>
|
||||
If using versions of polkit prior to 0.106 then it is only
|
||||
possible to validate (user, permission) pairs via the <code>.pkla</code>
|
||||
files. Fully validation of the (user, permission, object) triple
|
||||
requires the new JavaScript <code>.rules</code> support that
|
||||
was introduced in version 0.106. The latter is what will be
|
||||
described here.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Libvirt does not ship any rules files by default. It merely
|
||||
provides a definition of the default behaviour for each
|
||||
action (permission). As noted earlier, permissions which
|
||||
correspond to read-only operations in libvirt will be allowed
|
||||
to all users by default; everything else is denied by default.
|
||||
Defining custom rules requires creation of a file in the
|
||||
<code>/etc/polkit-1/rules.d</code> directory with a name
|
||||
chosen by the administrator (<code>100-libvirt-acl.rules</code>
|
||||
would be a reasonable choice). See the <code>polkit(8)</code>
|
||||
manual page for a description of how to write these files
|
||||
in general. The key idea is to create a file containing
|
||||
something like
|
||||
</p>
|
||||
|
||||
<pre>
|
||||
polkit.addRule(function(action, subject) {
|
||||
....logic to check 'action' and 'subject'...
|
||||
});
|
||||
</pre>
|
||||
|
||||
<p>
|
||||
In this code snippet above, the <code>action</code> object
|
||||
instance will represent the libvirt permission being checked
|
||||
along with identifying attributes for the object it is being
|
||||
applied to. The <code>subject</code> meanwhile will identify
|
||||
the libvirt client app (with the caveat above about it only
|
||||
dealing with local clients connected via the UNIX socket).
|
||||
On the <code>action</code> object, the permission name is
|
||||
accessible via the <code>id</code> attribute, while the
|
||||
object identifying attributes are exposed via the
|
||||
<code>lookup</code> method.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
See
|
||||
<a href="https://gitlab.com/libvirt/libvirt/-/tree/master/examples/polkit">source code</a>
|
||||
for a more complex example.
|
||||
</p>
|
||||
|
||||
<h3><a id="exconnect">Example: restricting ability to connect to drivers</a></h3>
|
||||
|
||||
<p>
|
||||
Consider a local user <code>berrange</code>
|
||||
who has been granted permission to connect to libvirt in
|
||||
full read-write mode. The goal is to only allow them to
|
||||
use the <code>QEMU</code> driver and not the Xen or LXC
|
||||
drivers which are also available in libvirtd.
|
||||
To achieve this we need to write a rule which checks
|
||||
whether the <code>connect_driver</code> attribute
|
||||
is <code>QEMU</code>, and match on an action
|
||||
name of <code>org.libvirt.api.connect.getattr</code>. Using
|
||||
the javascript rules format, this ends up written as
|
||||
</p>
|
||||
|
||||
<pre>
|
||||
polkit.addRule(function(action, subject) {
|
||||
if (action.id == "org.libvirt.api.connect.getattr" &&
|
||||
subject.user == "berrange") {
|
||||
if (action.lookup("connect_driver") == 'QEMU') {
|
||||
return polkit.Result.YES;
|
||||
} else {
|
||||
return polkit.Result.NO;
|
||||
}
|
||||
}
|
||||
});
|
||||
</pre>
|
||||
|
||||
<h3><a id="exdomain">Example: restricting access to a single domain</a></h3>
|
||||
|
||||
<p>
|
||||
Consider a local user <code>berrange</code>
|
||||
who has been granted permission to connect to libvirt in
|
||||
full read-write mode. The goal is to only allow them to
|
||||
see the domain called <code>demo</code> on the LXC driver.
|
||||
To achieve this we need to write a rule which checks
|
||||
whether the <code>connect_driver</code> attribute
|
||||
is <code>LXC</code> and the <code>domain_name</code>
|
||||
attribute is <code>demo</code>, and match on an action
|
||||
name of <code>org.libvirt.api.domain.getattr</code>. Using
|
||||
the javascript rules format, this ends up written as
|
||||
</p>
|
||||
|
||||
<pre>
|
||||
polkit.addRule(function(action, subject) {
|
||||
if (action.id == "org.libvirt.api.domain.getattr" &&
|
||||
subject.user == "berrange") {
|
||||
if (action.lookup("connect_driver") == 'LXC' &&
|
||||
action.lookup("domain_name") == 'demo') {
|
||||
return polkit.Result.YES;
|
||||
} else {
|
||||
return polkit.Result.NO;
|
||||
}
|
||||
}
|
||||
});
|
||||
</pre>
|
||||
</body>
|
||||
</html>
|
||||
310
docs/aclpolkit.rst
Normal file
310
docs/aclpolkit.rst
Normal file
@ -0,0 +1,310 @@
|
||||
.. role:: since
|
||||
|
||||
=====================
|
||||
Polkit access control
|
||||
=====================
|
||||
|
||||
Libvirt's client `access control framework <acl.html>`__ allows
|
||||
administrators to setup fine grained permission rules across client
|
||||
users, managed objects and API operations. This allows client
|
||||
connections to be locked down to a minimal set of privileges. The polkit
|
||||
driver provides a simple implementation of the access control framework.
|
||||
|
||||
.. contents::
|
||||
|
||||
Introduction
|
||||
------------
|
||||
|
||||
A default install of libvirt will typically use
|
||||
`polkit <https://www.freedesktop.org/wiki/Software/polkit/>`__ to
|
||||
authenticate the initial user connection to libvirtd. This is a very
|
||||
coarse grained check though, either allowing full read-write access to
|
||||
all APIs, or just read-only access. The polkit access control driver in
|
||||
libvirt builds on this capability to allow for fine grained control over
|
||||
the operations a user may perform on an object.
|
||||
|
||||
Permission names
|
||||
----------------
|
||||
|
||||
The libvirt `object names and permission names <acl.html#perms>`__ are
|
||||
mapped onto polkit action names using the simple pattern:
|
||||
|
||||
::
|
||||
|
||||
org.libvirt.api.$object.$permission
|
||||
|
||||
The only caveat is that any underscore characters in the object or
|
||||
permission names are converted to hyphens. So, for example, the
|
||||
``search_storage_vols`` permission on the ``storage_pool`` object maps
|
||||
to the polkit action:
|
||||
|
||||
::
|
||||
|
||||
org.libvirt.api.storage-pool.search-storage-vols
|
||||
|
||||
The default policy for any permission which corresponds to a "read only"
|
||||
operation, is to allow access. All other permissions default to deny
|
||||
access.
|
||||
|
||||
Object identity attributes
|
||||
--------------------------
|
||||
|
||||
To allow polkit authorization rules to be written to match against
|
||||
individual object instances, libvirt provides a number of authorization
|
||||
detail attributes when performing a permission check. The set of
|
||||
attributes varies according to the type of object being checked
|
||||
|
||||
virConnectPtr
|
||||
~~~~~~~~~~~~~
|
||||
|
||||
============== =====================================
|
||||
Attribute Description
|
||||
============== =====================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
============== =====================================
|
||||
|
||||
virDomainPtr
|
||||
~~~~~~~~~~~~
|
||||
|
||||
============== ============================================
|
||||
Attribute Description
|
||||
============== ============================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
domain_name Name of the domain, unique to the local host
|
||||
domain_uuid UUID of the domain, globally unique
|
||||
============== ============================================
|
||||
|
||||
virInterfacePtr
|
||||
~~~~~~~~~~~~~~~
|
||||
|
||||
+-------------------+---------------------------------------------------------+
|
||||
| Attribute | Description |
|
||||
+===================+=========================================================+
|
||||
| connect_driver | Name of the libvirt connection driver |
|
||||
+-------------------+---------------------------------------------------------+
|
||||
| interface_name | Name of the network interface, unique to the local host |
|
||||
+-------------------+---------------------------------------------------------+
|
||||
| interface_macaddr | MAC address of the network interface, not unique |
|
||||
+-------------------+---------------------------------------------------------+
|
||||
|
||||
virNetworkPtr
|
||||
~~~~~~~~~~~~~
|
||||
|
||||
============== =============================================
|
||||
Attribute Description
|
||||
============== =============================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
network_name Name of the network, unique to the local host
|
||||
network_uuid UUID of the network, globally unique
|
||||
============== =============================================
|
||||
|
||||
virNodeDevicePtr
|
||||
~~~~~~~~~~~~~~~~
|
||||
|
||||
================ =================================================
|
||||
Attribute Description
|
||||
================ =================================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
node_device_name Name of the node device, unique to the local host
|
||||
================ =================================================
|
||||
|
||||
virNWFilterPtr
|
||||
~~~~~~~~~~~~~~
|
||||
|
||||
============== ====================================================
|
||||
Attribute Description
|
||||
============== ====================================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
nwfilter_name Name of the network filter, unique to the local host
|
||||
nwfilter_uuid UUID of the network filter, globally unique
|
||||
============== ====================================================
|
||||
|
||||
virSecretPtr
|
||||
~~~~~~~~~~~~
|
||||
|
||||
=================== ===========================================
|
||||
Attribute Description
|
||||
=================== ===========================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
secret_uuid UUID of the secret, globally unique
|
||||
secret_usage_volume Name of the associated volume, if any
|
||||
secret_usage_ceph Name of the associated Ceph server, if any
|
||||
secret_usage_target Name of the associated iSCSI target, if any
|
||||
secret_usage_name Name of the associated TLS secret, if any
|
||||
=================== ===========================================
|
||||
|
||||
virStoragePoolPtr
|
||||
~~~~~~~~~~~~~~~~~
|
||||
|
||||
============== ==================================================
|
||||
Attribute Description
|
||||
============== ==================================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
pool_name Name of the storage pool, unique to the local host
|
||||
pool_uuid UUID of the storage pool, globally unique
|
||||
============== ==================================================
|
||||
|
||||
virStorageVolPtr
|
||||
~~~~~~~~~~~~~~~~
|
||||
|
||||
============== ==================================================
|
||||
Attribute Description
|
||||
============== ==================================================
|
||||
connect_driver Name of the libvirt connection driver
|
||||
pool_name Name of the storage pool, unique to the local host
|
||||
pool_uuid UUID of the storage pool, globally unique
|
||||
vol_name Name of the storage volume, unique to the pool
|
||||
vol_key Key of the storage volume, globally unique
|
||||
============== ==================================================
|
||||
|
||||
Hypervisor Driver connect_driver
|
||||
--------------------------------
|
||||
|
||||
The ``connect_driver`` parameter describes the client's `remote
|
||||
Connection Driver <remote.html>`__ name based on the `URI <uri.html>`__
|
||||
used for the connection.
|
||||
|
||||
:since:`Since 4.1.0`, when calling an API outside the scope of the primary
|
||||
connection driver, the primary driver will attempt to open a secondary
|
||||
connection to the specific API driver in order to process the API. For
|
||||
example, when hypervisor domain processing needs to make an API call
|
||||
within the storage driver or the network filter driver an attempt to
|
||||
open a connection to the "storage" or "nwfilter" driver will be made.
|
||||
Similarly, a "storage" primary connection may need to create a
|
||||
connection to the "secret" driver in order to process secrets for the
|
||||
API. If successful, then calls to those API's will occur in the
|
||||
``connect_driver`` context of the secondary connection driver rather
|
||||
than in the context of the primary driver. This affects the
|
||||
``connect_driver`` returned from rule generation from the
|
||||
``action.loookup`` function. The following table provides a list of the
|
||||
various connection drivers and the ``connect_driver`` name used by each
|
||||
regardless of primary or secondary connection. The access denied error
|
||||
message from libvirt will list the connection driver by name that denied
|
||||
the access.
|
||||
|
||||
Connection Driver Name
|
||||
~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
================= =======================
|
||||
Connection Driver ``connect_driver`` name
|
||||
================= =======================
|
||||
bhyve bhyve
|
||||
esx ESX
|
||||
hyperv Hyper-V
|
||||
interface interface
|
||||
xen Xen
|
||||
lxc LXC
|
||||
network network
|
||||
nodedev nodedev
|
||||
nwfilter NWFilter
|
||||
openvz OPENVZ
|
||||
qemu QEMU
|
||||
secret secret
|
||||
storage storage
|
||||
vbox VBOX
|
||||
vmware VMWARE
|
||||
vz vz
|
||||
================= =======================
|
||||
|
||||
User identity attributes
|
||||
------------------------
|
||||
|
||||
At this point in time, the only attribute provided by libvirt to
|
||||
identify the user invoking the operation is the PID of the client
|
||||
program. This means that the polkit access control driver is only useful
|
||||
if connections to libvirt are restricted to its UNIX domain socket. If
|
||||
connections are being made to a TCP socket, no identifying information
|
||||
is available and access will be denied. Also note that if the client is
|
||||
connecting via an SSH tunnel, it is the local SSH user that will be
|
||||
identified. In future versions, it is expected that more information
|
||||
about the client user will be provided, including the SASL / Kerberos
|
||||
username and/or x509 distinguished name obtained from the authentication
|
||||
provider in use.
|
||||
|
||||
Writing access control policies
|
||||
-------------------------------
|
||||
|
||||
If using versions of polkit prior to 0.106 then it is only possible to
|
||||
validate (user, permission) pairs via the ``.pkla`` files. Fully
|
||||
validation of the (user, permission, object) triple requires the new
|
||||
JavaScript ``.rules`` support that was introduced in version 0.106. The
|
||||
latter is what will be described here.
|
||||
|
||||
Libvirt does not ship any rules files by default. It merely provides a
|
||||
definition of the default behaviour for each action (permission). As
|
||||
noted earlier, permissions which correspond to read-only operations in
|
||||
libvirt will be allowed to all users by default; everything else is
|
||||
denied by default. Defining custom rules requires creation of a file in
|
||||
the ``/etc/polkit-1/rules.d`` directory with a name chosen by the
|
||||
administrator (``100-libvirt-acl.rules`` would be a reasonable choice).
|
||||
See the ``polkit(8)`` manual page for a description of how to write
|
||||
these files in general. The key idea is to create a file containing
|
||||
something like
|
||||
|
||||
::
|
||||
|
||||
polkit.addRule(function(action, subject) {
|
||||
....logic to check 'action' and 'subject'...
|
||||
});
|
||||
|
||||
In this code snippet above, the ``action`` object instance will
|
||||
represent the libvirt permission being checked along with identifying
|
||||
attributes for the object it is being applied to. The ``subject``
|
||||
meanwhile will identify the libvirt client app (with the caveat above
|
||||
about it only dealing with local clients connected via the UNIX socket).
|
||||
On the ``action`` object, the permission name is accessible via the
|
||||
``id`` attribute, while the object identifying attributes are exposed
|
||||
via the ``lookup`` method.
|
||||
|
||||
See `source
|
||||
code <https://gitlab.com/libvirt/libvirt/-/tree/master/examples/polkit>`__
|
||||
for a more complex example.
|
||||
|
||||
Example: restricting ability to connect to drivers
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
Consider a local user ``berrange`` who has been granted permission to
|
||||
connect to libvirt in full read-write mode. The goal is to only allow
|
||||
them to use the ``QEMU`` driver and not the Xen or LXC drivers which are
|
||||
also available in libvirtd. To achieve this we need to write a rule
|
||||
which checks whether the ``connect_driver`` attribute is ``QEMU``, and
|
||||
match on an action name of ``org.libvirt.api.connect.getattr``. Using
|
||||
the javascript rules format, this ends up written as
|
||||
|
||||
::
|
||||
|
||||
polkit.addRule(function(action, subject) {
|
||||
if (action.id == "org.libvirt.api.connect.getattr" &&
|
||||
subject.user == "berrange") {
|
||||
if (action.lookup("connect_driver") == 'QEMU') {
|
||||
return polkit.Result.YES;
|
||||
} else {
|
||||
return polkit.Result.NO;
|
||||
}
|
||||
}
|
||||
});
|
||||
|
||||
Example: restricting access to a single domain
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
Consider a local user ``berrange`` who has been granted permission to
|
||||
connect to libvirt in full read-write mode. The goal is to only allow
|
||||
them to see the domain called ``demo`` on the LXC driver. To achieve
|
||||
this we need to write a rule which checks whether the ``connect_driver``
|
||||
attribute is ``LXC`` and the ``domain_name`` attribute is ``demo``, and
|
||||
match on an action name of ``org.libvirt.api.domain.getattr``. Using the
|
||||
javascript rules format, this ends up written as
|
||||
|
||||
::
|
||||
|
||||
polkit.addRule(function(action, subject) {
|
||||
if (action.id == "org.libvirt.api.domain.getattr" &&
|
||||
subject.user == "berrange") {
|
||||
if (action.lookup("connect_driver") == 'LXC' &&
|
||||
action.lookup("domain_name") == 'demo') {
|
||||
return polkit.Result.YES;
|
||||
} else {
|
||||
return polkit.Result.NO;
|
||||
}
|
||||
}
|
||||
});
|
||||
@ -32,7 +32,6 @@ docs_assets = [
|
||||
|
||||
docs_html_in_files = [
|
||||
'404',
|
||||
'aclpolkit',
|
||||
'api_extension',
|
||||
'api',
|
||||
'apps',
|
||||
@ -106,6 +105,7 @@ docs_html_in_files = [
|
||||
]
|
||||
|
||||
docs_rst_files = [
|
||||
'aclpolkit',
|
||||
'advanced-tests',
|
||||
'best-practices',
|
||||
'ci',
|
||||
|
||||
Loading…
Reference in New Issue
Block a user