DLT component:

- Defined new dlt.proto file

proto/dlt.proto

@@ -12,72 +12,85 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//Example of topology
 syntax = "proto3";
 package dlt;
 
 import "context.proto";
 
 service DltService {
-  rpc RecordToDlt ( DltRecord ) returns ( RecordStatus ) {}
-  rpc GetFromDlt ( DltRecordId ) returns ( DltRecord ) {}
-  rpc SubscribeToDlt ( DltRecordSubscription ) returns ( stream DltRecord ) {}
-  rpc GetDltStatus ( context.Empty ) returns ( DltStatus ) {}
+  rpc RecordToDlt   (DltRecord                 ) returns (       DltRecordStatus  ) {}
+  rpc GetFromDlt    (DltRecordId               ) returns (       DltRecord        ) {}
+  rpc SubscribeToDlt(DltRecordSubscription     ) returns (stream DltRecordEvent   ) {}
+  rpc GetDltStatus  (context.TeraFlowController) returns (       DltPeerStatus    ) {}  // NEC is checkig if it is possible
+  rpc GetDltPeers   (context.Empty             ) returns (       DltPeerStatusList) {}  // NEC is checkig if it is possible
 }
 
-message DltRecordSubscription {
-  DltRecordType type = 1;
-  DltRecordOperation operation = 2;
+enum DltRecordTypeEnum {
+  DLTRECORDTYPE_UNDEFINED = 0;
+  DLTRECORDTYPE_CONTEXT   = 1;
+  DLTRECORDTYPE_TOPOLOGY  = 2;
+  DLTRECORDTYPE_DEVICE    = 3;
+  DLTRECORDTYPE_LINK      = 4;
+  DLTRECORDTYPE_SERVICE   = 5;
+  DLTRECORDTYPE_SLICE     = 6;
 }
 
-enum DltRecordType {
-  UNKNOWN = 0;
-  SERVICE = 1;
-  DEVICE = 2;
-  SLICE = 3;
+enum DltRecordOperationEnum {
+  DLTRECORDOPERATION_UNDEFINED = 0;
+  DLTRECORDOPERATION_ADD       = 1;
+  DLTRECORDOPERATION_UPDATE    = 2;
+  DLTRECORDOPERATION_DELETE    = 3;
 }
 
-enum DltRecordOperation {
-  ADD = 0;
-  UPDATE = 1;
-  DELETE = 2;
+enum DltRecordStatusEnum {
+  DLTRECORDSTATUS_UNDEFINED = 0;
+  DLTRECORDSTATUS_SUCCEEDED = 1;
+  DLTRECORDSTATUS_FAILED    = 2;
 }
 
-message DltRecord {
-  DltRecordId id = 1;
-  DltRecordType type = 2;  
-  DltRecordOperation operation = 3;
-  string json = 4;
+enum DltStatusEnum {
+  DLTSTATUS_UNDEFINED    = 0;
+  DLTSTATUS_NOTAVAILABLE = 1;
+  DLTSTATUS_INITIALIZED  = 2;
+  DLTSTATUS_AVAILABLE    = 3;
+  DLTSTATUS_DEINIT       = 4;
 }
 
 message DltRecordId {
-  context.Uuid id = 1;
+  context.Uuid      domain_uuid = 1;          // unique identifier of domain owning the record
+  DltRecordTypeEnum type        = 2;          // type of record
+  context.Uuid      record_uuid = 3;          // unique identifier of the record within the domain context_uuid/topology_uuid
 }
 
-message RecordStatus {
-  DltRecordId id = 1;
-  DltRecordStatusEnum status = 2;
+message DltRecord {
+  DltRecordId        record_id = 1;           // record identifier
+  DltRecordOperation operation = 2;           // operation to be performed over the record
+  string             data_json = 3;           // record content: JSON-encoded record content
 }
 
-enum DltRecordStatusEnum {
-  REQUESTED = 0;
-  STORED = 1;
-  DISABLED = 2;
+message DltRecordSubscription {
+  // retrieved events should match both conditions
+  // TODO: consider adding a more sophisticated filtering
+  repeated DltRecordType      type      = 1;  // only receive subscriptions of the selected types, empty=all
+  repeated DltRecordOperation operation = 2;  // only receive subscriptions of the selected operations, empty=all
 }
 
-
-message DltStatus {
-  context.TeraFlowController ctl = 1;
-  DltStatusEnum status = 2;
+message DltRecordEvent {
+  context.Event event     = 1;                // common event data (timestamp & event_type)
+  DltRecordId   record_id = 2;                // record identifier associated with this event
 }
 
-enum DltStatusEnum {
-  NOT_AVAILABLE = 0;
-  INITIALIZED = 1;
-  AVAILABLE = 2;
-  DEINIT = 3;
+message DltRecordStatus {
+  DltRecordId         record_id     = 1;      // identifier of the associated record
+  DltRecordStatusEnum status        = 2;      // status of the record
+  string              error_message = 3;      // error message in case of failure, empty otherwise
 }
 
+message DltPeerStatus {
+  context.TeraFlowController controller = 1;  // Identifier of the TeraFlow controller instance
+  DltStatusEnum              status     = 2;  // Status of the TeraFlow controller instance
+}
 
-
-
+message DltPeerStatusList {
+  repeated DltPeerStatus peers = 1;           // List of peers and their status
+}