Initial setup for workflow log tracing

Signed-off-by: Ryan Lettieri <ryanLettieri@microsoft.com>

src/Dapr.Workflow/WorkflowLoggingService.cs

@@ -0,0 +1,88 @@
+// ------------------------------------------------------------------------
+// Copyright 2022 The Dapr Authors
+// 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.
+// ------------------------------------------------------------------------
+
+namespace Dapr.Workflow
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Threading;
+    using System.Threading.Tasks;
+    using Microsoft.Extensions.Hosting;
+    using Microsoft.Extensions.Logging;
+
+    /// <summary>
+    /// Defines runtime options for workflows.
+    /// </summary>
+    internal sealed class WorkflowLoggingService : IHostedService
+    {
+        private readonly ILogger<WorkflowLoggingService> logger;
+        private static HashSet<string>? registeredWorkflows;
+        private static HashSet<string>? registeredActivities;
+        private LogLevel logLevel = LogLevel.Debug;
+
+        public WorkflowLoggingService(ILogger<WorkflowLoggingService> logger)
+        {
+            var value = Environment.GetEnvironmentVariable("DAPR_LOG_LEVEL");
+            logLevel = string.IsNullOrEmpty(value) ? LogLevel.Debug : (LogLevel)Enum.Parse(typeof(LogLevel), value);
+            this.logger = logger;
+            registeredActivities = new HashSet<string>();
+            registeredWorkflows = new HashSet<string>();
+        }
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            this.logger.Log(logLevel, "WorkflowLoggingService started");
+
+            if (registeredWorkflows != null)
+            {
+                this.logger.Log(logLevel, "List of registered workflows");
+                foreach (string item in registeredWorkflows)
+                {
+                    this.logger.Log(logLevel, item);
+                }
+            }
+
+            if (registeredActivities != null)
+            {
+                this.logger.Log(logLevel, "List of registered activities:");
+                foreach (string item in registeredActivities)
+                {
+                    this.logger.Log(logLevel, item);
+                }
+            }
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            this.logger.Log(logLevel, "WorkflowLoggingService stopped");
+
+            return Task.CompletedTask;
+        }
+
+        public static void LogWorkflowName(string workflowName)
+        {
+            if (registeredWorkflows != null)
+            {
+                registeredWorkflows.Add(workflowName);
+            }
+        }
+
+        public static void LogActivityName(string activityName)
+        {
+            if (registeredActivities != null)
+            {
+                registeredActivities.Add(activityName);
+            }
+        }
+    }
+}

src/Dapr.Workflow/WorkflowRuntimeOptions.cs

@@ -54,6 +54,7 @@ public void RegisterWorkflow<TInput, TOutput>(string name, Func<WorkflowContext,
                     WorkflowContext workflowContext = new DaprWorkflowContext(innerContext);
                     return implementation(workflowContext, input);
                 });
+                WorkflowLoggingService.LogWorkflowName(name);
             });
         }
 
@@ -73,6 +74,7 @@ public void RegisterWorkflow<TInput, TOutput>(string name, Func<WorkflowContext,
                     TWorkflow workflow = Activator.CreateInstance<TWorkflow>();
                     return new OrchestratorWrapper(workflow);
                 });
+                WorkflowLoggingService.LogWorkflowName(name);
             });
         }
 
@@ -91,6 +93,7 @@ public void RegisterActivity<TInput, TOutput>(string name, Func<WorkflowActivity
                     WorkflowActivityContext activityContext = new(innerContext);
                     return implementation(activityContext, input);
                 });
+                WorkflowLoggingService.LogActivityName(name);
             });
         }
 
@@ -111,6 +114,7 @@ public void RegisterActivity<TActivity>() where TActivity : class, IWorkflowActi
                     TActivity activity = ActivatorUtilities.CreateInstance<TActivity>(serviceProvider);
                     return new ActivityWrapper(activity);
                 });
+                WorkflowLoggingService.LogActivityName(name);
             });
         }
 

src/Dapr.Workflow/WorkflowServiceCollectionExtensions.cs

@@ -47,7 +47,7 @@ public static IServiceCollection AddDaprWorkflow(
 #pragma warning disable CS0618 // Type or member is obsolete - keeping around temporarily - replaced by DaprWorkflowClient
             serviceCollection.TryAddSingleton<WorkflowEngineClient>();
 #pragma warning restore CS0618 // Type or member is obsolete
-
+            serviceCollection.AddHostedService<WorkflowLoggingService>();
             serviceCollection.TryAddSingleton<DaprWorkflowClient>();
             serviceCollection.AddDaprClient();
             serviceCollection.AddDaprWorkflowClient();