Adding apex-pdp & distribution documents to parent

Change-Id: If8039f68a1669787685d4a7bdc37dec203901062
Issue-ID: POLICY-1898
Signed-off-by: ramverma <ram.krishna.verma@est.tech>

1 files changed, 51 insertions, 0 deletions

diff --git a/docs/distribution/Distribution-Introduction.rst b/docs/distribution/Distribution-Introduction.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+
+Introduction to Policy-Distribution
+***********************************
+
+         .. container:: paragraph
+
+            The main job of policy distribution component is to receive
+            incoming notifications, download artifacts, decode policies
+            from downloaded artifacts & forward the decoded policies to
+            all configured policy engines.
+
+|
+
+         .. container:: paragraph
+
+            The current implementation of distribution component comes
+            with built-in SDC reception handler for receiving incoming
+            distribution notifications from SDC using SDC client library.
+            Upon receiving the notification, the corresponding CSAR artifacts
+            are downloaded using SDC client library.The downloaded CSAR is
+            then given to the configured policy decoder for decoding and
+            generating policies. The generated policies are then forwarded
+            to all configured policy engines. Related distribution status
+            is sent to SDC at each step (download/deploy/done) during the
+            entire flow.
+
+|
+
+         .. container:: paragraph
+
+            The distribution component also comes with built-in REST based
+            endpoints for fetching health check status & statistical data
+            of running distribution system.
+
+|
+
+         .. container:: paragraph
+
+            The distribution component is designed using plugin based architecture.
+            All the handlers, decoders & forwarders are basically plugins to
+            the running distribution engine. The plugins are configured in the
+            configuration JSON file provided during startup of distribution engine.
+            Adding a new plugin is simply implementing the related interfaces,
+            adding them to the configuration JSON file & making the classes available
+            in the classpath while starting distribution engine. There is no need
+            to edit anything in the distribution core engine.
+            Refer to distribution user manual for more details about the system and
+            the configuration.