service-authz.html

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<h2>Request authorization</h2>

<h4>* Summary:</h4>
<p>
    The <a href="service-reqintake.html">Creation</a> process in the
    <a href="../faq.html#workspace-service">workspace service</a>
    makes an optional callout to authorize the request further than the basics. 
</p>
<p>
    <b>NOTE</b>: (see the end of this page for an overview of
    Nimbus authorization flow)
</p>

<hr />
<h4>* Java interface:</h4>

<ol>
<li>
<p>
    The basics are authorized by an implementation of this interface:
    <b>org.globus.workspace.service.binding.GlobalPolicies</b>
</p>

<p>
    Source code: <i>service/service/java/source/src/org/globus/workspace/service/binding/</i>
</p>
<p>
    Activated by way of the <i>$GLOBUS_LOCATION/etc/nimbus/workspace-service/other/main.xml</i>
    file -- see the "nimbus-rm.service.binding.GlobalPolicies" Spring bean.
</p>

</li>
<li>
<p>
    If configured, further authorization can be done by an implementation of this interface:
    <b>org.globus.workspace.service.binding.authorization.CreationAuthorizationCallout</b>
</p>

<p>
    Source code: <i>service/service/java/source/src/org/globus/workspace/service/binding/authorization/</i>
</p>
<p>
    Activated by way of the <i>$GLOBUS_LOCATION/etc/nimbus/workspace-service/other/main.xml</i>
    file -- see the "nimbus-rm.service.binding.Authorize" Spring bean.
</p>
</li>
</ol>


<hr />
<h4>* Default implementation:</h4>

<p>
    <b>org.globus.workspace.service.binding.defaults.DefaultGlobalPolicies</b>
</p>
<p>
    Source code: <i>service/service/java/source/src/org/globus/workspace/service/binding/defaults/</i>
</p>

<p>
    (there is no default CreationAuthorizationCallout, it is <b>optional</b>) 
</p>

<br />

<a name="groupauthz"> </a>
<h2>Group authorization plugin _NAMELINK(groupauthz)</h2>

<p>
    One implementation of <i>CreationAuthorizationCallout</i> is the groupauthz
    plugin.
</p>

<p>
    The plugin can enforce the following policies.  The request data
    to check is determined on a per-request, per-client basis.
    The <b>limits</b> are defined on a per group basis (every caller
    identity must be a part of a group).
</p>
<ul>
    <li>
        Maximum currently reserved minutes at one point in time.  If the
        caller has two other workspaces with 10 hours scheduled for each,
        the value being checked against this policy would be 20 hours
        plus whatever time the current request is.
    </li>
    <li>
        Maximum elapsed and currently reserved minutes at one point in
        time.  If the caller has one other workspace with 10 hours
        scheduled and 80 hours of recorded past usage, the value being
        checked against this policy would be 90 hours plus whatever time
        the current request is.  This is the all-time maximum usage cap.
    </li>
    <li>
        Maximum number of running workspaces at one point in time.
    </li>
    <li>
        Maximum number of workspaces per request (the largest group
        request possible).
    </li>
    <li>
        The image node that must be specified.
    </li>
    <li>
        The image node base directory that must be specified.
    </li>
    <li>
        Support for identity-hash based image subdirectories
        (see the cloud setup documentation to understand this
        convention).
    </li>
</ul>
<p>
    Each policy can be set to disabled/infinite for specific groups
    if you desire.
</p>

<br />

<a name="pythonauthz"> </a>
<h2>Python authorization plugin _NAMELINK(pythonauthz)</h2>
<p>
    We also distribute a Python based authorization plugin that allows an
    administrator to provide only a simple Python script to express policies
    (using the "Jython" library).
</p>

<p>
    This plugin is compatible with both
    <a href="http://dev.globus.org/wiki/VOMS">VOMS</a>
    and <a href="http://gridshib.globus.org/about.html">GridShib</a>
    attribute based authorization if either is enabled to protect the
    factory service create operation in the GT4 configuration.
</p>
        
<br />

<h2>Authorization flow</h2>

<p>
    Understanding the authorization possibilities requires some understanding
    of the factory service's <i>create</i> process, so the explanation below
    includes extra information that is not authorization related <i>per se</i>.
</p>

<h3>Default: gridmap setup</h3>

<p>
    The default installation is configured with gridmap authorization,
    a DN access control list, that allows only clients in the gridmap
    file to call the factory create operation.
</p>
<ul class="nobullets">
    <li>
        <img src="../img/1.png" alt="1" border="0">
        If the client's DN is not in the grid-mapfile list, the operation will
        will return a fault with the authorization error explained.
    </li>
</ul>
<p>
    The request is then validated and default values are filled in if not
    supplied by the client.  This is also where network addresses are leased
    if necessary.
</p>
<ul class="nobullets">
    <li>
        <img src="../img/2.png" alt="2" border="0">
        If the request is simply invalid, it will be denied and a
        WorkspaceMetadataFault will be returned.
    </li>
    <li>
        <img src="../img/3.png" alt="3" border="0">
        If the request is asking for network allocations and there are not
        enough, the request will be denied and a
        WorkspaceResourceRequestDeniedFault will be returned.
    </li>
</ul>
<p>
    Then the request is compared against the master policies configured
    in the factory.
</p>

<ul class="nobullets">
    <li>
        <img src="../img/4.png" alt="4" border="0">
        A violation will cause a WorkspaceResourceRequestDeniedFault to be
        returned.
    </li>
</ul>

<p>
    <br>
    <img alt="authorization flow 1" src="../img/authorization1.jpg"/>
</p>

<br />

<h3>Attribute based authorization</h3>

<p>
    The VOMS and GridShib modules run <i>before</i> the Workspace
    Factory Service is ever invoked, just like the gridmap authorization:
</p>

<p>
    <br>
    <img alt="authorization flow 2" src="../img/authorization2.jpg"/>
</p>

<p>
    As mentioned above there is a plugin interface for creation time
    authorization.  All relevant information about the request is passed
    to the plugin including client identity and attributes (if available)
    as well as the workspace description and resource request.  The
    callout to this plugin occurs <i>after the validation process</i>:
</p>

<p>
    <br>
    <img alt="authorization flow 3" src="../img/authorization3.jpg"/>
</p>

<p>
    The supplied Python based plugin allows an administrator to configure
    a much richer policy than the factory policies allow for.  For example,
    any arbitrary combination of <b>resource allocation</b> request (such as
    RAM), <b>network</b> settings, deployment <b>duration</b>,
    client <b>DN</b>, and client <b>attributes</b> can be taken into account.
</p>

<p>
    This implementation of the authorization callout can present both VOMS
    credentials and SAML attributes (via GridShib) to the policy evaluation.
    But before they can be consulted, the "PIP" (Policy Information Point)
    portion of those modules must be configured.  The PIP is what collects
    the attributes, the PDP (Policy Decision Point) is what enforces policy.
    This distinction is being mentioned because the PIP can be
    configured <i>without the PDP</i> in the VOMS and
    GridShib packages.  Bear in mind that this might be an option if you
    are using the workspace authorization callout and want to handle all
    attribute policy there instead of <i>before the factory service</i> which
    is when the VOMS and GridShib modules are run.  Thus, the PIP modules
    can collect the attributes about the client and then the detailed policy
    about those attributes can be expressed in the workspace creation time
    authorization callout.
</p>


<br />

<h3>Finally</h3>

<p>
    In all cases, <b>after the default policy check succeeds</b>, the request
    is currently passed next to the scheduling/resource management plugin where
    problems will also lead to a WorkspaceResourceRequestDeniedFault.
</p>

<p>
    <b>After scheduling succeeds</b>, the only thing stopping success at this
    point is an internal error (for example, a database connection problem).
</p>

<br />

<h3>Once deployed</h3>

<p>
    <i>Note:</i> Once deployed, a workspace can be managed and inspected
    via <a href="../interfaces/service.html">Workspace Service</a>
    or <a href="../interfaces/groupservice.html">Workspace Group Service</a>
    operations.  Also, destruction may be run when using groups of groups,
    Workspace Ensemble Service.
</p>
<p>
    Currently, no matter what authorization scheme is in use, once a workspace
    (or group of them) is deployed, al lof these operations are protected by a
    DN access control list consisting of the creator DN.  <b>Only the deployer
    can remotely manage or inspect the workspace</b>.
</p>

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