/// <summary>
/// Method to start monitoring a node and publish the data to IoTHub. Executes synchronously.
/// </summary>
private ServiceResult OnPublishNodeCall(ISystemContext context, MethodState method, IList <object> inputArguments, IList <object> outputArguments)
{
string logPrefix = "OnPublishNodeCall:";
if (string.IsNullOrEmpty(inputArguments[0] as string) || string.IsNullOrEmpty(inputArguments[1] as string))
{
Logger.Error($"{logPrefix} Invalid Arguments when trying to publish a node.");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide all arguments as strings!"));
}
HttpStatusCode statusCode = HttpStatusCode.InternalServerError;
NodeId nodeId = null;
ExpandedNodeId expandedNodeId = null;
Uri endpointUri = null;
bool isNodeIdFormat = true;
try
{
string id = inputArguments[0] as string;
if (id.Contains("nsu=", StringComparison.InvariantCulture))
{
expandedNodeId = ExpandedNodeId.Parse(id);
isNodeIdFormat = false;
}
else
{
nodeId = NodeId.Parse(id);
isNodeIdFormat = true;
}
endpointUri = new Uri(inputArguments[1] as string);
}
catch (UriFormatException)
{
Logger.Error($"{logPrefix} The EndpointUrl has an invalid format '{inputArguments[1] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA endpoint URL as second argument!"));
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} The NodeId has an invalid format '{inputArguments[0] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA NodeId in NodeId or ExpandedNodeId format as first argument!"));
}
// find/create a session to the endpoint URL and start monitoring the node.
try
{
// lock the publishing configuration till we are done
NodeConfiguration.OpcSessionsListSemaphore.Wait();
if (ShutdownTokenSource.IsCancellationRequested)
{
return(ServiceResult.Create(StatusCodes.BadUnexpectedError, $"Publisher shutdown in progress."));
}
// find the session we need to monitor the node
OpcUaSessionManager opcSession = NodeConfiguration.OpcSessions.FirstOrDefault(s => s.EndpointUrl.Equals(endpointUri.OriginalString, StringComparison.OrdinalIgnoreCase));
// add a new session.
if (opcSession == null)
{
// create new session info.
opcSession = new OpcUaSessionManager(endpointUri.OriginalString, true, OpcSessionCreationTimeout, OpcAuthenticationMode.Anonymous, null);
NodeConfiguration.OpcSessions.Add(opcSession);
Logger.Information($"OnPublishNodeCall: No matching session found for endpoint '{endpointUri.OriginalString}'. Requested to create a new one.");
}
if (isNodeIdFormat)
{
// add the node info to the subscription with the default publishing interval, execute syncronously
Logger.Debug($"{logPrefix} Request to monitor item with NodeId '{nodeId.ToString()}' (with default PublishingInterval and SamplingInterval)");
statusCode = opcSession.AddNodeForMonitoringAsync(nodeId, null, null, null, null, null, null, ShutdownTokenSource.Token).Result;
}
else
{
// add the node info to the subscription with the default publishing interval, execute syncronously
Logger.Debug($"{logPrefix} Request to monitor item with ExpandedNodeId '{expandedNodeId.ToString()}' (with default PublishingInterval and SamplingInterval)");
statusCode = opcSession.AddNodeForMonitoringAsync(null, expandedNodeId, null, null, null, null, null, ShutdownTokenSource.Token).Result;
}
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} Exception while trying to configure publishing node '{(isNodeIdFormat ? nodeId.ToString() : expandedNodeId.ToString())}'");
return(ServiceResult.Create(e, StatusCodes.BadUnexpectedError, $"Unexpected error publishing node: {e.Message}"));
}
finally
{
NodeConfiguration.OpcSessionsListSemaphore.Release();
}
if (statusCode == HttpStatusCode.OK || statusCode == HttpStatusCode.Accepted)
{
return(ServiceResult.Good);
}
return(ServiceResult.Create(StatusCodes.Bad, "Can not start monitoring node! Reason unknown."));
}
/// <summary>
/// Method to remove the node from the subscription and stop publishing telemetry to IoTHub. Executes synchronously.
/// </summary>
private ServiceResult OnUnpublishNodeCall(ISystemContext context, MethodState method, IList <object> inputArguments, IList <object> outputArguments)
{
string logPrefix = "OnUnpublishNodeCall:";
if (string.IsNullOrEmpty(inputArguments[0] as string) || string.IsNullOrEmpty(inputArguments[1] as string))
{
Logger.Error($"{logPrefix} Invalid arguments!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide all arguments!"));
}
HttpStatusCode statusCode = HttpStatusCode.InternalServerError;
NodeId nodeId = null;
ExpandedNodeId expandedNodeId = null;
Uri endpointUri = null;
bool isNodeIdFormat = true;
try
{
string id = inputArguments[0] as string;
if (id.Contains("nsu=", StringComparison.InvariantCulture))
{
expandedNodeId = ExpandedNodeId.Parse(id);
isNodeIdFormat = false;
}
else
{
nodeId = NodeId.Parse(id);
isNodeIdFormat = true;
}
endpointUri = new Uri(inputArguments[1] as string);
}
catch (UriFormatException)
{
Logger.Error($"{logPrefix} The endpointUrl is invalid '{inputArguments[1] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA endpoint URL as second argument!"));
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} The NodeId has an invalid format '{inputArguments[0] as string}'!");
return(ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA NodeId in NodeId or ExpandedNodeId format as first argument!"));
}
// find the session and stop monitoring the node.
try
{
NodeConfiguration.OpcSessionsListSemaphore.Wait();
if (ShutdownTokenSource.IsCancellationRequested)
{
return(ServiceResult.Create(StatusCodes.BadUnexpectedError, $"Publisher shutdown in progress."));
}
// find the session we need to monitor the node
OpcUaSessionManager opcSession = null;
try
{
opcSession = NodeConfiguration.OpcSessions.FirstOrDefault(s => s.EndpointUrl.Equals(endpointUri.OriginalString, StringComparison.OrdinalIgnoreCase));
}
catch
{
opcSession = null;
}
if (opcSession == null)
{
// do nothing if there is no session for this endpoint.
Logger.Error($"{logPrefix} Session for endpoint '{endpointUri.OriginalString}' not found.");
return(ServiceResult.Create(StatusCodes.BadSessionIdInvalid, "Session for endpoint of node to unpublished not found!"));
}
else
{
if (isNodeIdFormat)
{
// stop monitoring the node, execute syncronously
Logger.Information($"{logPrefix} Request to stop monitoring item with NodeId '{nodeId.ToString()}')");
statusCode = opcSession.RequestMonitorItemRemovalAsync(nodeId, null, ShutdownTokenSource.Token).Result;
}
else
{
// stop monitoring the node, execute syncronously
Logger.Information($"{logPrefix} Request to stop monitoring item with ExpandedNodeId '{expandedNodeId.ToString()}')");
statusCode = opcSession.RequestMonitorItemRemovalAsync(null, expandedNodeId, ShutdownTokenSource.Token).Result;
}
}
}
catch (Exception e)
{
Logger.Error(e, $"{logPrefix} Exception while trying to configure publishing node '{nodeId.ToString()}'");
return(ServiceResult.Create(e, StatusCodes.BadUnexpectedError, $"Unexpected error unpublishing node: {e.Message}"));
}
finally
{
NodeConfiguration.OpcSessionsListSemaphore.Release();
}
return(statusCode == HttpStatusCode.OK || statusCode == HttpStatusCode.Accepted ? ServiceResult.Good : ServiceResult.Create(StatusCodes.Bad, "Can not stop monitoring node!"));
}
/// <summary>
/// Create the publisher data structures to manage OPC sessions, subscriptions and monitored items.
/// </summary>
/// <returns></returns>
public async Task <bool> CreateOpcPublishingDataAsync()
{
// create a list to manage sessions, subscriptions and monitored items.
try
{
await PublisherNodeConfigurationSemaphore.WaitAsync().ConfigureAwait(false);
await OpcSessionsListSemaphore.WaitAsync().ConfigureAwait(false);
var uniqueEndpointUrls = _nodePublishingConfiguration.Select(n => n.EndpointUrl).Distinct();
foreach (var endpointUrl in uniqueEndpointUrls)
{
var currentNodePublishingConfiguration = _nodePublishingConfiguration.First(n => n.EndpointUrl == endpointUrl);
EncryptedNetworkCredential encryptedAuthCredential = null;
if (currentNodePublishingConfiguration.OpcAuthenticationMode == OpcAuthenticationMode.UsernamePassword)
{
if (currentNodePublishingConfiguration.EncryptedAuthCredential == null)
{
throw new NullReferenceException($"Could not retrieve credentials to authenticate to the server. Please check if 'OpcAuthenticationUsername' and 'OpcAuthenticationPassword' are set in configuration.");
}
encryptedAuthCredential = currentNodePublishingConfiguration.EncryptedAuthCredential;
}
// create new session info.
OpcUaSessionManager opcSession = new OpcUaSessionManager(endpointUrl, currentNodePublishingConfiguration.UseSecurity, OpcSessionCreationTimeout, currentNodePublishingConfiguration.OpcAuthenticationMode, encryptedAuthCredential);
// create a subscription for each distinct publishing inverval
var nodesDistinctPublishingInterval = _nodePublishingConfiguration.Where(n => n.EndpointUrl.Equals(endpointUrl, StringComparison.OrdinalIgnoreCase)).Select(c => c.OpcPublishingInterval).Distinct();
foreach (var nodeDistinctPublishingInterval in nodesDistinctPublishingInterval)
{
// create a subscription for the publishing interval and add it to the session.
OpcUaSubscriptionManager opcSubscription = new OpcUaSubscriptionManager(nodeDistinctPublishingInterval);
// add all nodes with this OPC publishing interval to this subscription.
var nodesWithSamePublishingInterval = _nodePublishingConfiguration.Where(n => n.EndpointUrl.Equals(endpointUrl, StringComparison.OrdinalIgnoreCase)).Where(n => n.OpcPublishingInterval == nodeDistinctPublishingInterval);
foreach (var nodeInfo in nodesWithSamePublishingInterval)
{
// differentiate if NodeId or ExpandedNodeId format is used
if (nodeInfo.ExpandedNodeId != null)
{
// create a monitored item for the node, we do not have the namespace index without a connected session.
// so request a namespace update.
OpcUaMonitoredItemManager opcMonitoredItem = new OpcUaMonitoredItemManager(nodeInfo.ExpandedNodeId, opcSession.EndpointUrl,
nodeInfo.OpcSamplingInterval, nodeInfo.DisplayName, nodeInfo.HeartbeatInterval, nodeInfo.SkipFirst);
opcSubscription.OpcMonitoredItems.Add(opcMonitoredItem);
Interlocked.Increment(ref NodeConfigVersion);
}
else if (nodeInfo.NodeId != null)
{
// create a monitored item for the node with the configured or default sampling interval
OpcUaMonitoredItemManager opcMonitoredItem = new OpcUaMonitoredItemManager(nodeInfo.NodeId, opcSession.EndpointUrl,
nodeInfo.OpcSamplingInterval, nodeInfo.DisplayName, nodeInfo.HeartbeatInterval, nodeInfo.SkipFirst);
opcSubscription.OpcMonitoredItems.Add(opcMonitoredItem);
Interlocked.Increment(ref NodeConfigVersion);
}
else
{
Logger.Error($"Node {nodeInfo.OriginalId} has an invalid format. Skipping...");
}
}
// add subscription to session.
opcSession.OpcSubscriptions.Add(opcSubscription);
}
// add session.
OpcSessions.Add(opcSession);
}
}
catch (Exception e)
{
Logger.Fatal(e, "Creation of the internal OPC data managment structures failed. Exiting...");
return(false);
}
finally
{
OpcSessionsListSemaphore.Release();
PublisherNodeConfigurationSemaphore.Release();
}
return(true);
}
