Handle PNF in AaiCtxBuilder

Issue-ID: LOG-764
Change-Id: I1af65f604751d7412cc12e7a42f2dc785d39a90c
Signed-off-by: Leigh, Phillip (pl876u) <phillip.leigh@amdocs.com>

2 files changed, 510 insertions, 11 deletions

diff --git a/src/main/java/org/onap/pomba/contextbuilder/aai/datatype/PnfInstance.java b/src/main/java/org/onap/pomba/contextbuilder/aai/datatype/PnfInstance.java
new file mode 100644
index 0000000..f470b78
--- /dev/null
+++ b/src/main/java/org/onap/pomba/contextbuilder/aai/datatype/PnfInstance.java
@@ -0,0 +1,317 @@
+/*
+ * ============LICENSE_START===================================================
+ * Copyright (c) 2018 Amdocs
+ * ============================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================================
+ */
+
+package org.onap.pomba.contextbuilder.aai.datatype;
+
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.annotations.Expose;
+import com.google.gson.annotations.SerializedName;
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.onap.pomba.contextbuilder.aai.exception.AuditError;
+import org.onap.pomba.contextbuilder.aai.exception.AuditException;
+
+public class PnfInstance {
+
+    @SerializedName("pnf-id")
+    @Expose
+    private String pnfId;
+    @SerializedName("pnf-name")
+    @Expose
+    private String pnfName;
+    @SerializedName("nf-function")
+    @Expose
+    private String nfFunction;
+    @SerializedName("nf-role")
+    @Expose
+    private String nfRole;
+    @SerializedName("resource-version")
+    @Expose
+    private String resourceVersion;
+    @SerializedName("pnf-name2")
+    @Expose
+    private String pnfName2;
+    @SerializedName("pnf-name2-source")
+    @Expose
+    private String pnfName2Source;
+    @SerializedName("equip-type")
+    @Expose
+    private String equipmentType;
+    @SerializedName("equip-vendor")
+    @Expose
+    private String equipmentVendor;
+    @SerializedName("equip-model")
+    @Expose
+    private String equipmentModel;
+    @SerializedName("management-option")
+    @Expose
+    private String managementOptions;
+    @SerializedName("sw-version")
+    @Expose
+    private String swVersion;
+    @SerializedName("frame-id")
+    @Expose
+    private String frameId;
+    @SerializedName("serial-number")
+    @Expose
+    private String serialNumber;
+    @SerializedName("model-invariant-id")
+    @Expose
+    private String modelInvariantId;
+    @SerializedName("model-version-id")
+    @Expose
+    private String modelVersionId;
+
+    public String getModelInvariantId() {
+        return modelInvariantId;
+    }
+    public String getPnfId() {
+        return pnfId;
+    }
+
+    public void setPnfId(String pnfId) {
+        this.pnfId = pnfId;
+    }
+
+    public String getPnfName() {
+        return pnfName;
+    }
+
+    public void setPnfName(String name) {
+        this.pnfName = name;
+    }
+    public String getNfFunction() {
+        return nfFunction;
+    }
+
+    public void setNfFunction(String nfFunction) {
+        this.nfFunction = nfFunction;
+    }
+
+    public String getNfRole() {
+        return nfRole;
+    }
+
+    public void setNfRole(String networkRole) {
+        this.nfRole = networkRole;
+    }
+    public String getResourceVersion() {
+        return resourceVersion;
+    }
+
+    public void setResourceVersion(String resourceVersion) {
+        this.resourceVersion = resourceVersion;
+    }
+
+    public String getPnfName2() {
+        return pnfName2;
+    }
+
+    public void setPnfName2(String name2) {
+        this.pnfName2 = name2;
+    }
+
+    public String getPnfName2Source() {
+        return pnfName2Source;
+    }
+
+    public void setPnfName2Source(String name2Source) {
+        this.pnfName2Source = name2Source;
+    }
+
+    public String getEquipmentType() {
+        return equipmentType;
+    }
+
+    public void setEquipmentType(String equipmentType) {
+        this.equipmentType = equipmentType;
+    }
+
+    public String getEquipmentVendor() {
+        return equipmentVendor;
+    }
+
+    public void setEquipmentVendor(String equipmentVendor) {
+        this.equipmentVendor = equipmentVendor;
+    }
+
+    public String getEquipmentModel() {
+        return equipmentModel;
+    }
+
+    public void setEquipmentModel(String equipmentModel) {
+        this.equipmentModel = equipmentModel;
+    }
+
+    public String getManagementOptions() {
+        return managementOptions;
+    }
+
+    public void setManagementOptions(String managementOptions) {
+        this.managementOptions = managementOptions;
+    }
+
+    public String getSwVersion() {
+        return swVersion;
+    }
+
+    public void setSwVersion(String swVersion) {
+        this.swVersion = swVersion;
+    }
+
+    public String getFrameId() {
+        return frameId;
+    }
+
+    public void setFrameId(String frameId) {
+        this.frameId = frameId;
+    }
+
+    public String getSerialNumber() {
+        return serialNumber;
+    }
+
+    public void setSerialNumber(String serialNumber) {
+        this.serialNumber = serialNumber;
+    }
+
+    public void setModelInvariantId(String modelInvariantId) {
+        this.modelInvariantId = modelInvariantId;
+    }
+
+    public String getModelVersionId() {
+        return modelVersionId;
+    }
+
+    public void setModelVersionId(String modelVersionId) {
+        this.modelVersionId = modelVersionId;
+    }
+
+
+    private static final Gson gson = new GsonBuilder().disableHtmlEscaping().create();
+
+    public String toJson() {
+        return gson.toJson(this);
+    }
+
+
+    public static PnfInstance fromJson(String payload) throws AuditException {
+        try {
+            if (payload == null || payload.isEmpty()) {
+                throw new AuditException("Empty Json response");
+            }
+            return gson.fromJson(payload, PnfInstance.class);
+        } catch (Exception ex) {
+            throw new AuditException(AuditError.JSON_READER_PARSE_ERROR, ex);
+        }
+    }
+
+    /**
+     * No args constructor for use in serialization
+     *
+     */
+    public PnfInstance() {
+    }
+
+    /**
+    *
+    * @param uuid
+    * @param name
+    * @param networkRole
+    * @param name2
+    * @param name2Source
+    * @param equipmentType
+    * @param equipmentVendor
+    * @param equipmentModel
+    * @param managementOptions
+    * @param swVersion
+    * @param frameId
+    * @param serialNumber
+    * @param modelInvariantId
+    * @param modelVersionId
+    *
+    */
+   public PnfInstance(String uuid, String name, String networkRole, String name2, String name2Source,String equipmentType,String equipmentVendor,String equipmentModel,String managementOptions,String swVersion, String frameId, String serialNumber, String modelInvariantId, String modelVersionId) {
+       super();
+       this.pnfId = uuid;
+       this.pnfName = name;
+       this.nfRole = networkRole;
+       this.pnfName2 = name2;
+       this.pnfName2Source = name2Source;
+       this.equipmentType = equipmentType;
+       this.equipmentVendor = equipmentVendor;
+       this.equipmentModel = equipmentModel;
+       this.managementOptions = managementOptions;
+       this.swVersion = swVersion;
+       this.frameId = frameId;
+       this.serialNumber = serialNumber;
+       this.modelInvariantId = modelInvariantId;
+       this.modelVersionId = modelVersionId;
+   }
+
+
+
+    /////////// common functions //////////////////////
+    @Override
+    public String toString() {
+        return new ToStringBuilder(this)
+                .append("uuid", pnfId)
+                .append("name", pnfName)
+                .append("networkRole", nfRole)
+                .append("name2", pnfName2)
+                .append("name2Source", pnfName2Source)
+                .append("equipmentType", equipmentType)
+                .append("equipmentVendor", equipmentVendor)
+                .append("equipmentModel", equipmentModel)
+                .append("managementOptions", managementOptions)
+                .append("swVersion", swVersion)
+                .append("frameId", frameId)
+                .append("serialNumber", serialNumber)
+                .append("modelInvariantId", modelInvariantId)
+                .append("modelVersionId", modelVersionId)
+               .toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return new HashCodeBuilder().append(pnfId).append(frameId).append(serialNumber).append(modelInvariantId).append(modelVersionId).toHashCode();
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+        if (!(other instanceof PnfInstance)) {
+            return false;
+        }
+        PnfInstance rhs = ((PnfInstance) other);
+        return new EqualsBuilder()
+                .append(pnfId, rhs.pnfId)
+                .append(pnfName, rhs.pnfName)
+                .append(pnfName2, rhs.pnfName2)
+                .append(equipmentType, rhs.equipmentType)
+                .append(equipmentModel, rhs.equipmentModel)
+                .append(frameId, rhs.frameId)
+                .append(serialNumber, rhs.serialNumber)
+                .isEquals();
+    }
+}
diff --git a/src/main/java/org/onap/pomba/contextbuilder/aai/util/RestUtil.java b/src/main/java/org/onap/pomba/contextbuilder/aai/util/RestUtil.java
index 1f34cc6..88f3db4 100644
--- a/src/main/java/org/onap/pomba/contextbuilder/aai/util/RestUtil.java
+++ b/src/main/java/org/onap/pomba/contextbuilder/aai/util/RestUtil.java
@@ -37,7 +37,8 @@ import org.onap.pomba.common.datatypes.Attribute;
 import org.onap.pomba.common.datatypes.DataQuality;
 import org.onap.pomba.common.datatypes.ModelContext;
 import org.onap.pomba.common.datatypes.Service;
-import org.onap.pomba.common.datatypes.VF;
+//import org.onap.pomba.common.datatypes.VF;
+import org.onap.pomba.common.datatypes.VNF;
 import org.onap.pomba.common.datatypes.VFModule;
 import org.onap.pomba.common.datatypes.VM;
 import org.onap.pomba.common.datatypes.VNFC;
@@ -53,7 +54,9 @@ import org.onap.pomba.contextbuilder.aai.exception.AuditError;
 import org.onap.pomba.contextbuilder.aai.exception.AuditException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
+import org.onap.pomba.contextbuilder.aai.datatype.PnfInstance;
+import org.onap.pomba.common.datatypes.PNF;
+import com.bazaarvoice.jolt.JsonUtils;
 
 public class RestUtil {
 
@@ -80,6 +83,7 @@ public class RestUtil {
     private static final String VF_MODULES = "vf-modules";
     private static final String VF_MODULE = "vf-module";
 
+    private static final String CATALOG_PNF = "pnf";
 
     // Relationship Json Path
     private static final String RELATIONSHIP_LIST = "relationship-list";
@@ -100,6 +104,20 @@ public class RestUtil {
     private static final String HOSTNAME = "hostName";
     private static final String IMAGEID = "imageId";
 
+    //Attribute Names for PNF
+    private static final String PNF_NETWORK_FUNCTION = "networkFunction";
+    private static final String PNF_NETWORK_ROLE = "networkRole";
+    private static final String PNF_RESOURCE_VERSION = "resourceVersion";
+    private static final String PNF_NAME2 = "name2";
+    private static final String PNF_NAME2_SOURCE = "name2Source";
+    private static final String PNF_EQUIPMENT_TYPE = "equipType";
+    private static final String PNF_EQUIPMENT_VENDOR = "equipVendor";
+    private static final String PNF_EQUIPMENT_MODEL = "equipModel";
+    private static final String PNF_MANAGEMENT_OPTIONS = "managementOptions";
+    private static final String PNF_SW_VERSION = "swVersion";
+    private static final String PNF_FRAME_ID = "frameId";
+    private static final String PNF_SERIAL_NUMBER = "serialNumber";
+
     /**
      * Validates the URL parameter.
      *
@@ -183,6 +201,8 @@ public class RestUtil {
             return null;
         }
 
+        log.info("ResourceLink from AAI:" + resourceLink);
+
         // Build URl to get ServiceInstance Payload
         String url = baseURL + resourceLink;
 
@@ -196,6 +216,7 @@ public class RestUtil {
             // Only return the empty Json on the root level. i.e service instance
             return null;
         }
+        log.info("Message from AAI:" + JsonUtils.toPrettyJsonString(JsonUtils.jsonToObject(serviceInstancePayload)) );
 
         List<String> genericVNFLinkLst = extractRelatedLink(serviceInstancePayload, CATALOG_GENERIC_VNF);
         log.info(LogMessages.NUMBER_OF_API_CALLS, "genericVNF", genericVNFLinkLst.size());
@@ -212,6 +233,8 @@ public class RestUtil {
             if (isEmptyJson(genericVNFPayload)) {
                 log.info(LogMessages.NOT_FOUND, "GenericVNF with url ", genericVNFLink);
             } else {
+                log.info("Message from AAI for VNF " + genericVNFURL + ",message body:" + JsonUtils.toPrettyJsonString(JsonUtils.jsonToObject(genericVNFPayload)) );
+
                 // Logic to Create the Generic VNF Instance POJO object
                 VnfInstance vnfInstance = VnfInstance.fromJson(genericVNFPayload);
                 vnfLst.add(vnfInstance);
@@ -224,8 +247,35 @@ public class RestUtil {
 
             }
         }
+
+        //Obtain PNF (Physical Network Function)
+        List<String> genericPNFLinkLst = extractRelatedLink(serviceInstancePayload, CATALOG_PNF);
+        log.info(LogMessages.NUMBER_OF_API_CALLS, "PNF", genericPNFLinkLst.size());
+        log.info(LogMessages.API_CALL_LIST, "PNF", printOutAPIList(genericPNFLinkLst));
+
+        String genericPNFPayload = null;
+        List<PnfInstance> pnfLst = new ArrayList<PnfInstance>(); // List of the PNF POJO object
+
+        for (String genericPNFLink : genericPNFLinkLst) {
+            // With latest AAI development, in order to retrieve the both generic PNF
+            String genericPNFURL = baseURL + genericPNFLink;
+            // Response from generic PNF API call
+            genericPNFPayload =
+                    getResource(aaiClient, genericPNFURL, aaiBasicAuthorization, transactionId, MediaType.valueOf(MediaType.APPLICATION_JSON));
+
+            if (isEmptyJson(genericPNFPayload)) {
+                log.info(LogMessages.NOT_FOUND, "GenericPNF with url ", genericPNFLink);
+            } else {
+                log.info("Message from AAI for PNF " + genericPNFLink + ",message body:" + JsonUtils.toPrettyJsonString(JsonUtils.jsonToObject(genericPNFPayload)) );
+
+                // Logic to Create the Generic VNF Instance POJO object
+                PnfInstance pnfInstance = PnfInstance.fromJson(genericPNFPayload);
+                pnfLst.add(pnfInstance);
+            }
+        }
+
         // Transform to common model and return
-        return transform(ServiceInstance.fromJson(serviceInstancePayload), vnfLst, vnfcMap, vnf_vfmodule_vserver_Map);
+        return transform(ServiceInstance.fromJson(serviceInstancePayload), vnfLst, vnfcMap, vnf_vfmodule_vserver_Map, pnfLst);
     }
 
     /*
@@ -250,6 +300,7 @@ public class RestUtil {
             if (isEmptyJson(vnfcPayload)) {
                 log.info(LogMessages.NOT_FOUND, "VNFC with url", vnfcLink);
             } else {
+                log.info("Message from AAI for VNFC with url " + vnfcLink + ",message body:" + JsonUtils.toPrettyJsonString(JsonUtils.jsonToObject(vnfcPayload)) );
                 // Logic to Create the VNFC POJO object
                 VnfcInstance vnfcInstance = VnfcInstance.fromJson(vnfcPayload);
                 vnfcLst.add(vnfcInstance);
@@ -322,18 +373,18 @@ public class RestUtil {
      * Transform AAI Representation to Common Model
      */
     private static ModelContext transform(ServiceInstance svcInstance, List<VnfInstance> vnfLst,
-            Map<String, List<VnfcInstance>> vnfcMap,  Map<String, Map<String, List<Vserver>>> vnf_vfmodule_vserver_Map) {
+            Map<String, List<VnfcInstance>> vnfcMap,  Map<String, Map<String, List<Vserver>>> vnf_vfmodule_vserver_Map, List<PnfInstance> pnfLst_fromAAi) {
         ModelContext context = new ModelContext();
         Service service = new Service();
-        service.setInvariantUuid(svcInstance.getModelInvariantId());
+        service.setModelInvariantUUID(svcInstance.getModelInvariantId());
         service.setName(svcInstance.getServiceInstanceName());
         service.setUuid(svcInstance.getServiceInstanceId());
         service.setDataQuality(DataQuality.ok());
-        List<VF> vfLst = new ArrayList<VF>();
+        List<VNF> vfLst = new ArrayList<VNF>();
 
         for (VnfInstance vnf : vnfLst) {
-            VF vf = new VF();
-            vf.setInvariantUuid(vnf.getModelInvariantId());
+            VNF vf = new VNF();
+            vf.setModelInvariantUUID(vnf.getModelInvariantId());
             vf.setName(vnf.getVnfName());
             vf.setUuid(vnf.getModelVersionId());
             vf.setType(vnf.getVnfType());
@@ -350,7 +401,7 @@ public class RestUtil {
 
                     for (VnfcInstance vnfc : vnfcInstanceLst) {
                         VNFC vnfcModel = new VNFC();
-                        vnfcModel.setInvariantUuid(vnfc.getModelInvariantId());
+                        vnfcModel.setModelInvariantUUID(vnfc.getModelInvariantId());
                         vnfcModel.setName(vnfc.getVnfcName());
                         vnfcModel.setUuid(vnfc.getModelVersionId());
                         vnfcLst.add(vnfcModel);
@@ -381,7 +432,7 @@ public class RestUtil {
 
                             VFModule vfModule = new VFModule();
                             vfModule.setUuid(modelVersionId);
-                            vfModule.setInvariantUuid(modelInvariantId);
+                            vfModule.setModelInvariantUUID(modelInvariantId);
                             vfModule.setMaxInstances(getMaxInstance(vfmoduleEntry.getKey(), maxInstanceMap));
                             vfModule.setDataQuality(DataQuality.ok());
 
@@ -440,11 +491,142 @@ public class RestUtil {
         } // done the vnfInstance
 
         context.setService(service);
-        context.setVfs(vfLst);
+        context.setVnfs(vfLst);
+        //Add PNF info
+        context.setPnfs(transformPNF(pnfLst_fromAAi));
 
         return context;
     }
 
+    /*
+     * Transform AAI Representation to Common Model
+     */
+    public static List<PNF> transformPNF(List<PnfInstance> pnfLst_from_AAI) {
+        if (pnfLst_from_AAI.isEmpty()) {
+            log.info(LogMessages.API_CALL_LIST, "Nill PNF list");
+           return null;
+        }
+        List<PNF> pnfLst = new ArrayList<PNF>();
+
+        for (PnfInstance pnf_from_aai : pnfLst_from_AAI) {
+            PNF pnf = new PNF();
+            pnf.setModelInvariantUUID(pnf_from_aai.getPnfId());
+            pnf.setName(pnf_from_aai.getPnfName());
+            pnf.setModelVersionID(pnf_from_aai.getModelVersionId());
+            pnf.setModelInvariantUUID(pnf_from_aai.getModelInvariantId());
+            pnf.setDataQuality(DataQuality.ok());
+            List<Attribute>  attributeList = new ArrayList<Attribute>();
+            pnf.setAttributes(attributeList);
+
+            // Iterate through the ENUM Attribute list
+            for (Attribute.Name  name: Attribute.Name.values()) {
+                if (name.toString().equals(PNF_NETWORK_FUNCTION )) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.networkFunction);
+                    att.setValue(String.valueOf( pnf_from_aai.getNfFunction()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_NETWORK_ROLE )) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.networkRole);
+                    att.setValue(String.valueOf( pnf_from_aai.getNfRole()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_RESOURCE_VERSION)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.resourceVersion);
+                    att.setValue(String.valueOf( pnf_from_aai.getResourceVersion()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_NAME2)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.name2);
+                    att.setValue(String.valueOf( pnf_from_aai.getPnfName2()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_NAME2_SOURCE )) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.name2Source);
+                    att.setValue(String.valueOf( pnf_from_aai.getPnfName2Source()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_EQUIPMENT_TYPE )) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.equipType);
+                    att.setValue(String.valueOf( pnf_from_aai.getEquipmentType()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_EQUIPMENT_VENDOR )) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.equipVendor);
+                    att.setValue(String.valueOf( pnf_from_aai.getEquipmentVendor()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_EQUIPMENT_MODEL)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.equipModel);
+                    att.setValue(String.valueOf( pnf_from_aai.getEquipmentModel()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_MANAGEMENT_OPTIONS)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.managementOptions);
+                    att.setValue(String.valueOf( pnf_from_aai.getManagementOptions()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_SW_VERSION)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.swVersion);
+                    att.setValue(String.valueOf( pnf_from_aai.getManagementOptions()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_FRAME_ID)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.frameId);
+                    att.setValue(String.valueOf( pnf_from_aai.getFrameId()));
+                    attributeList.add(att);
+                }
+
+                if (name.toString().equals(PNF_SERIAL_NUMBER)) {
+                    Attribute att = new Attribute();
+                    att.setDataQuality(DataQuality.ok());
+                    att.setName(Attribute.Name.serialNumber);
+                    att.setValue(String.valueOf( pnf_from_aai.getSerialNumber()));
+                    attributeList.add(att);
+                }
+
+            }
+
+            pnf.setAttributes(attributeList);
+            pnfLst.add(pnf);
+
+        } // done the vnfInstance
+
+
+        return pnfLst;
+    }
+
 
     /*
      * Return the Vserver Attribute value by looking through the relationship. i.e. if "related-to" is "pserver", we will get