Add workflow sample monitor

all.sln

@@ -97,6 +97,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BulkPublishEventExample", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WorkflowUnitTest", "examples\Workflow\WorkflowUnitTest\WorkflowUnitTest.csproj", "{8CA09061-2BEF-4506-A763-07062D2BD6AC}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkflowMonitor", "examples\Workflow\WorkflowMonitor\WorkflowMonitor.csproj", "{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64}"
+EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "GeneratedActor", "GeneratedActor", "{7592AFA4-426B-42F3-AE82-957C86814482}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ActorClient", "examples\GeneratedActor\ActorClient\ActorClient.csproj", "{61C24126-F39D-4BEA-96DC-FC87BA730554}"
@@ -263,6 +265,10 @@ Global
 		{DDC41278-FB60-403A-B969-2AEBD7C2D83C}.Release|Any CPU.Build.0 = Release|Any CPU
 		{8CA09061-2BEF-4506-A763-07062D2BD6AC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{8CA09061-2BEF-4506-A763-07062D2BD6AC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64}.Release|Any CPU.Build.0 = Release|Any CPU
 		{61C24126-F39D-4BEA-96DC-FC87BA730554}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{61C24126-F39D-4BEA-96DC-FC87BA730554}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{61C24126-F39D-4BEA-96DC-FC87BA730554}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -348,6 +354,7 @@ Global
 		{4A175C27-EAFE-47E7-90F6-873B37863656} = {0EF6EA64-D7C3-420D-9890-EAE8D54A57E6}
 		{DDC41278-FB60-403A-B969-2AEBD7C2D83C} = {0EF6EA64-D7C3-420D-9890-EAE8D54A57E6}
 		{8CA09061-2BEF-4506-A763-07062D2BD6AC} = {BF3ED6BF-ADF3-4D25-8E89-02FB8D945CA9}
+		{0E3D4544-31FA-458D-8B1C-2F4E4B6D9E64} = {BF3ED6BF-ADF3-4D25-8E89-02FB8D945CA9}
 		{7592AFA4-426B-42F3-AE82-957C86814482} = {D687DDC4-66C5-4667-9E3A-FD8B78ECAA78}
 		{61C24126-F39D-4BEA-96DC-FC87BA730554} = {7592AFA4-426B-42F3-AE82-957C86814482}
 		{CB903D21-4869-42EF-BDD6-5B1CFF674337} = {7592AFA4-426B-42F3-AE82-957C86814482}

examples/Workflow/WorkflowMonitor/Activities/CheckStatus.cs

@@ -0,0 +1,14 @@
+using Dapr.Workflow;
+
+namespace WorkflowMonitor.Activities
+{
+    public class CheckStatus : WorkflowActivity<bool, string>
+    {
+        static List<string> status = new List<string>() { "healthy", "unhealthy" };
+        Random random = new Random();
+        public override Task<string> RunAsync(WorkflowActivityContext context, bool input)
+        {
+            return Task.FromResult<string>(status[random.Next(status.Count)]);
+        }
+    }
+}

examples/Workflow/WorkflowMonitor/Program.cs

@@ -0,0 +1,57 @@
+using Dapr.Client;
+using Dapr.Workflow;
+using WorkflowMonitor.Activities;
+using WorkflowMonitor.Workflows;
+using Microsoft.Extensions.Hosting;
+
+const string DaprWorkflowComponent = "dapr";
+
+// The workflow host is a background service that connects to the sidecar over gRPC
+var builder = Host.CreateDefaultBuilder(args).ConfigureServices(services =>
+{
+    services.AddDaprWorkflow(options =>
+    {
+        options.RegisterWorkflow<DemoWorkflow>();
+        options.RegisterActivity<CheckStatus>();
+    });
+});
+
+// Dapr uses a random port for gRPC by default. If we don't know what that port
+// is (because this app was started separate from dapr), then assume 4001.
+if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("DAPR_GRPC_PORT")))
+{
+    Environment.SetEnvironmentVariable("DAPR_GRPC_PORT", "4001");
+}
+
+// Start the app - this is the point where we connect to the Dapr sidecar to
+// listen for workflow work-items to execute.
+using var host = builder.Build();
+host.Start();
+
+
+DaprClient daprClient = new DaprClientBuilder().Build();
+
+while (!await daprClient.CheckHealthAsync())
+{
+    Thread.Sleep(TimeSpan.FromSeconds(5));
+}
+
+using (daprClient)
+{
+    Console.WriteLine($"Workflow Started.");
+    await daprClient.WaitForSidecarAsync();
+
+    string instanceId = $"demo-workflow-{Guid.NewGuid().ToString()[..8]}";
+
+    bool isHealthy = true;
+    await daprClient.StartWorkflowAsync(
+    workflowComponent: DaprWorkflowComponent,
+    workflowName: nameof(DemoWorkflow),
+    instanceId: instanceId,
+    input: isHealthy);
+
+
+    await daprClient.WaitForWorkflowCompletionAsync(
+        workflowComponent: DaprWorkflowComponent,
+        instanceId: instanceId);
+}

examples/Workflow/WorkflowMonitor/WorkflowMonitor.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\src\Dapr.Workflow\Dapr.Workflow.csproj" />
+  </ItemGroup>
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <NoWarn>612,618</NoWarn>
+  </PropertyGroup>
+
+</Project>

examples/Workflow/WorkflowMonitor/Workflows/DemoWorkflow.cs

@@ -0,0 +1,39 @@
+using Dapr.Workflow;
+using WorkflowMonitor.Activities;
+
+namespace WorkflowMonitor.Workflows
+{
+    public class DemoWorkflow : Workflow<bool, bool>
+    {
+        public override async Task<bool> RunAsync(WorkflowContext context, bool isHealthy)
+        {
+            string status = await context.CallActivityAsync<string>(nameof(CheckStatus), true);
+            int next_sleep_interval;
+            if (!context.IsReplaying)
+            {
+                Console.WriteLine($"This job is {status}");
+            }
+
+            if (status == "healthy")
+            {
+                isHealthy = true;
+                next_sleep_interval = 30;
+            }
+            else
+            {
+                if (isHealthy)
+                {
+                    isHealthy = false;
+                }
+                Console.WriteLine($"Status is unhealthy. Set check interval to 1s");
+                next_sleep_interval = 5;
+            }
+
+            await context.CreateTimer(TimeSpan.FromSeconds(next_sleep_interval));
+            context.ContinueAsNew(isHealthy);
+
+            // This workflow will never complete.
+            return true;
+        }
+    }
+}