Document Policy to CDS contract

This contract needs to be respected by a CDS blueprint developer
and hence documenting it into the repo.

Issue-ID: POLICY-2277
Signed-off-by: Rashmi Pujar <rashmi.pujar@bell.ca>
Change-Id: Iece51380b9bd99af1e307c8e6c411b0bc860e7ba

1 files changed, 268 insertions, 0 deletions

diff --git a/docs/actors/cds.rst b/docs/actors/cds.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
+
+CDS actor support in Policy
+###########################
+
+.. contents::
+    :depth: 4
+
+1. Overview of CDS Actor support in Policy
+==========================================
+ONAP Policy Framework now enables Controller Design Studio (CDS) as one of the supported actors.
+This allows the users to configure Operational Policy to use CDS as an actor to remedy a situation.
+
+Behind the scene, when an incoming event is received and validated against rules, Policy uses gRPC to trigger
+the CBA (Controller Blueprint Archive: CDS artifact) as configured in the operational policy and providing CDS
+with all the input parameters that is required to execute the chosen CBA.
+
+2. Objective
+============
+The goal of the user guide is to clarify the contract between Policy and CDS so that a CBA developer can respect
+this input contract towards CDS when implementing the CBA.
+
+3. Contract between Policy and CDS
+==================================
+Policy upon receiving an incoming event from DCAE fires the rules and decides which actor to trigger.
+If the CDS actor is the chosen, Policy triggers the CBA execution using gRPC.
+
+The parameters required for the execution of a CBA are internally handled by Policy.
+It makes uses of the incoming event, the operational policy configured and AAI lookup to build the CDS request payload.
+
+3.1 CDS Blueprint Execution Payload format as invoked by Policy
+---------------------------------------------------------------
+Below are the details of the contract established between Policy and CDS to enable the automation of a remediation
+action within the scope of a closed loop usecase in ONAP.
+
+The format of the input payload for CDS follows the below guidelines, hence a CBA developer must consider this when
+implementing the CBA logic.
+For the sake of simplicity a JSON payload is used instead of a gRPC payload and each attribute of the child-nodes
+is documented.
+
+3.1.1 CommonHeader
+******************
+
+The "commonHeader" field in the CBA execute payload is built by policy.
+
+=============================== =========== ================================================================
+   "commonHeader" field name       type                             Description
+=============================== =========== ================================================================
+subRequestId                      string      Generated by Policy. Is a UUID and used internally by policy.
+requestId                         string      Inserted by Policy. Maps to the UUID sent by DCAE i.e. the ID
+                                              used throughout the closed loop lifecycle to identify a request.
+originatorId                      string      Generated by Policy and fixed to "POLICY"
+=============================== =========== ================================================================
+
+3.1.2 ActionIdentifiers
+***********************
+
+The "actionIdentifiers" field uniquely identifies the CBA and the workflow to execute.
+
+==================================== =========== =============================================================
+   "actionIdentifiers" field name       type                         Description
+==================================== =========== =============================================================
+mode                                   string      Inserted by Policy and fixed to "sync" presently.
+blueprintName                          string      Inserted by Policy. Maps to the attribute that holds the
+                                                   blueprint-name in the operational policy configuration.
+blueprintVersion                       string      Inserted by Policy. Maps to the attribute that holds the
+                                                   blueprint-version in the operational policy configuration.
+actionName                             string      Inserted by Policy. Maps to the attribute that holds the
+                                                   action-name in the operational policy configuration.
+==================================== =========== =============================================================
+
+3.1.3 Payload
+*************
+
+The "payload" JSON node is generated by Policy for the action-name specified in the "actionIdentifiers" field
+which is eventually supplied through the operational policy configuration as indicated above.
+
+3.1.3.1 Action request object
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The "$actionName-request" object is generated by CDS for the action-name specified in the "actionIdentifiers" field.
+
+The "$actionName-request" object contains:
+
+* a field called "resolution-key" which CDS uses to store the resolved parameters into the CDS context
+* a child node object called "$actionName-properties" which holds a map of all the parameters that serve
+  as inputs to the CBA. It presently holds the below information:
+
+  * all the AAI enriched attributes
+  * additional parameters embedded in the Control Loop Event format which is sent by DCAE (analytics application).
+  * any static information supplied through operational policy configuration which is not specific to an event
+    but applies across all the events.
+
+The data description for the action request object fields is as below:
+
+- Resolution-key
+
+===================================== =========== ======================================================================
+   "$actionName-request" field name      type                                Description
+===================================== =========== ======================================================================
+resolution-key                          string      Generated by Policy. Is a UUID, generated each time CBA execute
+                                                    request is invoked.
+===================================== =========== ======================================================================
+
+- Action properties object
+
+======================================== =============== ===============================================================
+   "$actionName-properties" field name        type                               Description
+======================================== =============== ===============================================================
+[$aai_node_type.$aai_attribute]              map             Inserted by Policy after performing AAI enrichment.
+                                                             Is a map that contains AAI parameters for the target and
+                                                             conforms to the notation: $aai_node_type.$aai_attribute.
+                                                             E.g. for PNF the map looks like below.
+
+                                                                       .. code-block:: json
+
+                                                                         {
+                                                                           "pnf.equip-vendor":"Vendor-A",
+                                                                           "pnf.ipaddress-v4-oam":"10.10.10.10",
+                                                                           "pnf.in-maint":false,
+                                                                           "pnf.pnf-ipv4-address":"3.3.3.3",
+                                                                           "pnf.resource-version":"1570746989505",
+                                                                           "pnf.nf-role":"ToR DC101",
+                                                                           "pnf.equip-type":"Router",
+                                                                           "pnf.equip-model":"model-123456",
+                                                                           "pnf.frame-id":"3",
+                                                                           "pnf.pnf-name":"demo-pnf"
+                                                                         }
+data                                        json object       Inserted by Policy. Maps to the static payload supplied
+                                            OR string         through operational policy configuration. Used to hold
+                                                              any static information which applies across all the
+                                                              events as described above. If the value of the data
+                                                              field is a valid JSON string it is converted to a JSON
+                                                              object, else will be retained as a string.
+[$additionalEventParams]                     map              Inserted by Policy. Maps to the map of
+                                                              additionalEvent parameters embedded into the
+                                                              Control Loop Event message from DCAE.
+======================================== =============== ===============================================================
+
+
+
+3.1.4 Summing it up: CBA execute payload generation as done by Policy
+*********************************************************************
+
+Putting all the above information together below is the REST equivalent of the CDS blueprint execute gRPC request
+generated by Policy.
+
+REST equivalent of the gRPC request from Policy to CDS to execute a CBA.
+
+.. code-block:: bash
+
+    curl -X POST \
+      'http://{{ip}}:{{port}}/api/v1/execution-service/process' \
+      -H 'Content-Type: application/json' \
+      -H 'cache-control: no-cache' \
+      -d '{
+        "commonHeader":{
+            "subRequestId":"{generated_by_policy}",
+            "requestId":"{req_id_from_DCAE}",
+            "originatorId":"POLICY"
+        },
+        "actionIdentifiers":{
+            "mode":"sync",
+            "blueprintName":"{blueprint_name_from_operational_policy_config}",
+            "blueprintVersion":"{blueprint_version_from_operational_policy_config}",
+            "actionName":"{blueprint_action_name_from_operational_policy_config}"
+        },
+        "payload":{
+            "$actionName-request":{
+                "resolution-key":"{generated_by_policy}",
+                "$actionName-properties":{
+                    "$aai_node_type.$aai_attribute_1":"",
+                    "$aai_node_type.$aai_attribute_2":"",
+                    .........
+                    "data":"{static_payload_data_from_operational_policy_config}",
+                    "$additionalEventParam_1":"",
+                    "$additionalEventParam_2":"",
+                    .........
+                }
+            }
+        }
+    }'
+
+3.1.5 Examples
+**************
+
+Sample CBA execute request generated by Policy for PNF target type when "data" field is a string:
+
+.. code-block:: bash
+
+    curl -X POST \
+      'http://{{ip}}:{{port}}/api/v1/execution-service/process' \
+      -H 'Content-Type: application/json' \
+      -H 'cache-control: no-cache' \
+      -d '{
+        "commonHeader":{
+            "subRequestId":"14384b21-8224-4055-bb9b-0469397db801",
+            "requestId":"d57709fb-bbec-491d-a2a6-8a25c8097ee8",
+            "originatorId":"POLICY"
+        },
+        "actionIdentifiers":{
+            "mode":"sync",
+            "blueprintName":"PNF-demo",
+            "blueprintVersion":"1.0.0",
+            "actionName":"reconfigure-pnf"
+        },
+        "payload":{
+            "reconfigure-pnf-request":{
+                "resolution-key":"8338b828-51ad-4e7c-ac8b-08d6978892e2",
+                "reconfigure-pnf-properties":{
+                    "pnf.equip-vendor":"Vendor-A",
+                    "pnf.ipaddress-v4-oam":"10.10.10.10",
+                    "pnf.in-maint":false,
+                    "pnf.pnf-ipv4-address":"3.3.3.3",
+                    "pnf.resource-version":"1570746989505",
+                    "pnf.nf-role":"ToR DC101",
+                    "pnf.equip-type":"Router",
+                    "pnf.equip-model":"model-123456",
+                    "pnf.frame-id":"3",
+                    "pnf.pnf-name":"demo-pnf",
+                    "data": "peer-as=64577",
+                    "peer-group":"demo-peer-group",
+                    "neighbor-address":"4.4.4.4"
+                }
+            }
+        }
+    }'
+
+Sample CBA execute request generated by Policy for VNF target type when "data" field is a valid JSON string:
+
+.. code-block:: bash
+
+    curl -X POST \
+      'http://{{ip}}:{{port}}/api/v1/execution-service/process' \
+      -H 'Content-Type: application/json' \
+      -H 'cache-control: no-cache' \
+      -d '{
+        "commonHeader":{
+            "subRequestId":"14384b21-8224-4055-bb9b-0469397db801",
+            "requestId":"d57709fb-bbec-491d-a2a6-8a25c8097ee8",
+            "originatorId":"POLICY"
+        },
+        "actionIdentifiers":{
+            "mode":"sync",
+            "blueprintName":"vFW-CDS",
+            "blueprintVersion":"1.0.0",
+            "actionName":"config-deploy"
+        },
+        "payload":{
+            "config-deploy-request":{
+                "resolution-key":"6128eb53-0eac-4c79-855c-ff56a7b81141",
+                "config-deploy-properties":{
+                    "service-instance.service-instance-id":"40004db6-c51f-45b0-abab-ea4156bae422",
+                    "generic-vnf.vnf-id":"8d09e3bd-ae1d-4765-b26e-4a45f568a092",
+                    "data":{
+                        "active-streams":"7"
+                    }
+                }
+            }
+        }
+    }'
+
+4. Operational Policy configuration to use CDS as an actor
+==========================================================
+
+TODO: Document once Operational Policy TOSCA YAML redesign is finalized.