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diff --git a/docs/xacml/xacml-tutorial.rst b/docs/xacml/xacml-tutorial.rst new file mode 100644 index 00000000..72271adb --- /dev/null +++ b/docs/xacml/xacml-tutorial.rst @@ -0,0 +1,330 @@ +.. This work is licensed under a Creative Commons Attribution 4.0 International License. + +.. _xacmltutorial-label: + +Policy XACML - Custom Application Tutorial +########################################## + +.. toctree:: + :maxdepth: 3 + +This tutorial shows how to build a XACML application for a Policy Type. Please be sure to clone the +policy repositories before going through the tutorial. See :ref:`<policy-dev-label>` for details. + + +Design a Policy Type +******************** +Follow :ref:`TOSCA Policy Primer <tosca-label>` for more information. For the tutorial, we will use +this example Policy Type in which an ONAP PEP client would like to enforce an action **authorize** +for a *user* to execute a *permission* on an *entity*. + +.. literalinclude:: tutorial/tutorial-policy-type.yaml + :language: JSON + :caption: Example Tutorial Policy Type + :linenos: + +We would expect then to be able to create the following policies to allow the demo user to Read/Write +a entity called foo. While the audit user can only read the entity called foo. No user has Delete +permission. + +.. literalinclude:: tutorial/tutorial-policies.yaml + :language: JSON + :caption: Example Policies Derived From Tutorial Policy Type + :linenos: + +Design Decision Request and expected Decision Response +****************************************************** +For the PEP (Policy Enforcement Point) client applications that call the Decision API, you need +to design how the Decision API Request resource fields will be sent via the PEP. + +.. literalinclude:: tutorial/tutorial-decision-request.json + :language: JSON + :caption: Example Decision Request + :linenos: + +For simplicity, we expect only a *Permit* or *Deny* in the Decision Response. + +.. literalinclude:: tutorial/tutorial-decision-response.json + :language: JSON + :caption: Example Decision Response + :linenos: + +Create A Maven Project +********************** +This part of the tutorial assumes you understand how to use Eclipse to create a Maven +project. Please follow any examples for the Eclipse installation you have to create +an empty application. For the tutorial, use groupId *org.onap.policy.tutorial* and artifactId +*tutorial*. + +.. image:: tutorial/images/eclipse-create-maven.png + +.. image:: tutorial/images/eclipse-maven-project.png + +Be sure to import the policy/xacml-pdp project into Eclipse. + +.. image:: tutorial/images/eclipse-import.png + +Add Dependencies Into Application pom.xml +***************************************** + +.. code-block:: java + :caption: pom.xml dependencies + + <dependency> + <groupId>org.onap.policy.xacml-pdp.applications</groupId> + <artifactId>common</artifactId> + <version>2.1.0-SNAPSHOT</version> + </dependency> + +Create META-INF to expose Java Service +************************************** +The ONAP XACML PDP Engine will not be able to find the tutorial application unless it has +a property file located in src/main/resources/META-INF/services that contains a property file +declaring the class that implements the service. + +The name of the file must match **org.onap.policy.pdp.xacml.application.common.XacmlApplicationServiceProvider** +and the contents of the file is one line **org.onap.policy.tutorial.tutorial.TutorialApplication**. + +.. image:: tutorial/images/eclipse-meta-inf.png + +Create A Java Class That Extends **StdXacmlApplicationServiceProvider** +*********************************************************************** +You could implement **XacmlApplicationServiceProvider** if you wish, but +for simplicity if you just extend **StdXacmlApplicationServiceProvider** you +will get a lot of implementation done for your application up front. All +that needs to be implemented is providing a custom translator. + +.. image:: tutorial/images/eclipse-inherit-app.png + +.. code-block:: java + :caption: Custom Tutorial Application Service Provider + :emphasize-lines: 6 + + package org.onap.policy.tutorial.tutorial; + + import org.onap.policy.pdp.xacml.application.common.ToscaPolicyTranslator; + import org.onap.policy.pdp.xacml.application.common.std.StdXacmlApplicationServiceProvider; + + public class TutorialApplication extends StdXacmlApplicationServiceProvider { + + @Override + protected ToscaPolicyTranslator getTranslator(String type) { + // TODO Auto-generated method stub + return null; + } + + } + +Override Methods for Tutorial +***************************** +Override these methods to differentiate Tutorial from other applications so that the XACML PDP +Engine can determine how to route policy types and policies to the application. + +.. code-block:: java + :caption: Custom Tutorial Application Service Provider + + package org.onap.policy.tutorial.tutorial; + + import java.util.Arrays; + import java.util.List; + + import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyTypeIdentifier; + import org.onap.policy.pdp.xacml.application.common.ToscaPolicyTranslator; + import org.onap.policy.pdp.xacml.application.common.std.StdXacmlApplicationServiceProvider; + + public class TutorialApplication extends StdXacmlApplicationServiceProvider { + + private final ToscaPolicyTypeIdentifier supportedPolicyType = new ToscaPolicyTypeIdentifier(); + + @Override + public String applicationName() { + return "tutorial"; + } + + @Override + public List<String> actionDecisionsSupported() { + return Arrays.asList("authorize"); + } + + @Override + public synchronized List<ToscaPolicyTypeIdentifier> supportedPolicyTypes() { + return Arrays.asList(supportedPolicyType); + } + + @Override + public boolean canSupportPolicyType(ToscaPolicyTypeIdentifier policyTypeId) { + return supportedPolicyType.equals(policyTypeId); + } + + @Override + protected ToscaPolicyTranslator getTranslator(String type) { + // TODO Auto-generated method stub + return null; + } + + } + +Create A Translation Class that extends the ToscaPolicyTranslator Class +*********************************************************************** +Please be sure to review the existing translators in the policy/xacml-pdp repo to see if they could +be re-used for your policy type. For the tutorial, we will create our own translator. + +The custom translator is not only responsible for translating Policies derived from the Tutorial +Policy Type, but also for translating Decision API Requests/Responses to/from the appropriate XACML +requests/response objects the XACML engine understands. + +.. code-block:: java + :caption: Custom Tutorial Translator Class + + package org.onap.policy.tutorial.tutorial; + + import org.onap.policy.models.decisions.concepts.DecisionRequest; + import org.onap.policy.models.decisions.concepts.DecisionResponse; + import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy; + import org.onap.policy.pdp.xacml.application.common.ToscaPolicyConversionException; + import org.onap.policy.pdp.xacml.application.common.ToscaPolicyTranslator; + + import com.att.research.xacml.api.Request; + import com.att.research.xacml.api.Response; + + import oasis.names.tc.xacml._3_0.core.schema.wd_17.PolicyType; + + public class TutorialTranslator implements ToscaPolicyTranslator { + + public PolicyType convertPolicy(ToscaPolicy toscaPolicy) throws ToscaPolicyConversionException { + // TODO Auto-generated method stub + return null; + } + + public Request convertRequest(DecisionRequest request) { + // TODO Auto-generated method stub + return null; + } + + public DecisionResponse convertResponse(Response xacmlResponse) { + // TODO Auto-generated method stub + return null; + } + + } + +Implement the TutorialTranslator Methods +**************************************** +This is the part where knowledge of the XACML OASIS 3.0 specification is required. Please refer to +that specification on the many ways to design a XACML Policy. + +For the tutorial, we will build code that translates the TOSCA Policy into one XACML Policy that matches +on the user and action. It will then have one or more rules for each entity and permission combination. The +default combining algorithm for the XACML Rules are to "Deny Unless Permit". + +.. Note:: + There are many ways to build the policy based on the attributes. How to do so is a matter of experience and + fine tuning using the many options for combining algorithms, target and/or condition matching and the rich set of + functions available. + +Here is one implementation example: + +.. literalinclude:: tutorial/app/src/main/java/org/onap/policy/tutorial/tutorial/TutorialTranslator.java + :caption: Example Translator Implementation + :linenos: + +Use the TutorialTranslator in the TutorialApplication +***************************************************** +Be sure to go back to the TutorialApplication and create an instance of the translator to return to the +StdXacmlApplicationServiceProvider. The StdXacmlApplicationServiceProvider uses the translator to convert +a policy when a new policy is deployed to the ONAP XACML PDP Engine. + +.. code-block:: java + :caption: Final TutorialApplication Class + :linenos: + :emphasize-lines: 37 + + package org.onap.policy.tutorial.tutorial; + + import java.util.Arrays; + import java.util.List; + + import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicyTypeIdentifier; + import org.onap.policy.pdp.xacml.application.common.ToscaPolicyTranslator; + import org.onap.policy.pdp.xacml.application.common.std.StdXacmlApplicationServiceProvider; + + public class TutorialApplication extends StdXacmlApplicationServiceProvider { + + private final ToscaPolicyTypeIdentifier supportedPolicyType = new ToscaPolicyTypeIdentifier(); + private final TutorialTranslator translator = new TutorialTranslator(); + + @Override + public String applicationName() { + return "tutorial"; + } + + @Override + public List<String> actionDecisionsSupported() { + return Arrays.asList("authorize"); + } + + @Override + public synchronized List<ToscaPolicyTypeIdentifier> supportedPolicyTypes() { + return Arrays.asList(supportedPolicyType); + } + + @Override + public boolean canSupportPolicyType(ToscaPolicyTypeIdentifier policyTypeId) { + return supportedPolicyType.equals(policyTypeId); + } + + @Override + protected ToscaPolicyTranslator getTranslator(String type) { + return translator; + } + + } + +Create a XACML Request from ONAP Decision Request +************************************************* +The easiest way to do this is to use the annotations feature from XACML PDP library to create an example XACML +request. Then create an instance and simply populate it from an incoming ONAP Decision Request. + +.. image: tutorial/images/eclipse-create-request.png + +.. literalinclude:: tutorial/app/src/main/java/org/onap/policy/tutorial/tutorial/TutorialRequest.java + :caption: Example Decision Request to Decision Response Implementation + :linenos: + + +Create xacml.properties for the XACML PDP engine to use +******************************************************* +In the applications *src/test/resources* directory, create a xacml.properties file that will be used by the embedded +XACML PDP Engine when loading. + +.. literalinclude:: tutorial/tutorial-xacml.properties + :caption: Example xacml.properties file + :linenos: + :emphasize-lines: 20, 25 + +Create a JUnit and use the TestUtils.java class in application/common +********************************************************************* +Using Eclipse, create a JUnit and be sure to add a setup() method stub. Here you will be utilizing a TestUtils.java +class from the policy/xamcl-pdp repo's application/common submodule to use some utility methods for building the JUnit test. + +.. image: tutorial/images/eclipse-junit-create.png + +Copy the TOSCA Policy Type :download:`link <tutorial/tutorial-policy-type.yaml>` and the TOSCA Policies :download:`link <tutorial/tutorial-policies.yaml>` +into the src/test/resources directory. + +We will create a temporary folder which is used by the **StdXacmlApplicationServiceProvider** to store working copies of policies as they are loaded +into the application. + +.. literalinclude:: tutorial/app/src/test/java/org/onap/policy/tutorial/tutorial/TutorialApplicationTest.java + :caption: Example Translator Implementation + :linenos: + +Run the JUnit test!! + +Where To Go From Here +********************* +Once you have created enough JUnit tests that test the TutorialTranslator.java and TutorialRequest.java classes, you are ready to now make your +application available to the ONAP XACML PDP Engine. These steps are covered in another tutorial. + + + |