Add dependency injection sample (#30)

Fixes #9

README.md

@@ -23,6 +23,7 @@ Prerequisites:
 * [ActivityWorker](src/ActivityWorker) - Use .NET activities from a workflow in another language.
 * [AspNet](src/AspNet) - Demonstration of a generic host worker and an ASP.NET workflow starter.
 * [ClientMtls](src/ClientMtls) - How to use client certificate authentication, e.g. for Temporal Cloud.
+* [DependencyInjection](src/DependencyInjection) - How to inject dependencies in activities and use generic hosts for workers
 * [Encryption](src/Encryption) - End-to-end encryption with Temporal payload codecs.
 * [Polling](src/Polling) - Recommended implementation of an activity that needs to periodically poll an external resource waiting its successful completion.
 * [Schedules](src/Schedules) - How to schedule workflows to be run at specific times in the future.

TemporalioSamples.sln

@@ -43,6 +43,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TemporalioSamples.Polling.I
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TemporalioSamples.Polling.PeriodicSequence", "src\Polling\PeriodicSequence\TemporalioSamples.Polling.PeriodicSequence.csproj", "{11A5854B-EE6E-4752-9C46-F466503D853B}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TemporalioSamples.DependencyInjection", "src\DependencyInjection\TemporalioSamples.DependencyInjection.csproj", "{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -116,6 +118,10 @@ Global
 		{11A5854B-EE6E-4752-9C46-F466503D853B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{11A5854B-EE6E-4752-9C46-F466503D853B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{11A5854B-EE6E-4752-9C46-F466503D853B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{7AECC7C6-9A21-4B8A-84D9-AFC4F5840CAF} = {1A647B41-53D0-4638-AE5A-6630BAAE45FC}
@@ -136,5 +142,6 @@ Global
 		{6935B8AC-160F-463D-BE03-AD6FF31585A3} = {AE21E7F4-B114-4761-81B1-8FA63E9F6BB8}
 		{DD2DE0CF-C127-461B-B4F1-D4E13BDD3B5D} = {AE21E7F4-B114-4761-81B1-8FA63E9F6BB8}
 		{11A5854B-EE6E-4752-9C46-F466503D853B} = {AE21E7F4-B114-4761-81B1-8FA63E9F6BB8}
+		{10E6F7C9-7F6C-4A8E-94A1-99C10F46BBA4} = {1A647B41-53D0-4638-AE5A-6630BAAE45FC}
 	EndGlobalSection
 EndGlobal

src/DependencyInjection/IMyDatabaseClient.cs

@@ -0,0 +1,6 @@
+namespace TemporalioSamples.DependencyInjection;
+
+public interface IMyDatabaseClient
+{
+    Task<string> SelectValueAsync(string table);
+}

src/DependencyInjection/MyActivities.cs

@@ -0,0 +1,14 @@
+namespace TemporalioSamples.DependencyInjection;
+
+using Temporalio.Activities;
+
+public class MyActivities
+{
+    private readonly IMyDatabaseClient databaseClient;
+
+    public MyActivities(IMyDatabaseClient databaseClient) => this.databaseClient = databaseClient;
+
+    [Activity]
+    public Task<string> SelectFromDatabaseAsync(string table) =>
+        databaseClient.SelectValueAsync(table);
+}

src/DependencyInjection/MyDatabaseClient.cs

@@ -0,0 +1,7 @@
+namespace TemporalioSamples.DependencyInjection;
+
+public class MyDatabaseClient : IMyDatabaseClient
+{
+    public Task<string> SelectValueAsync(string table) =>
+        Task.FromResult($"some-db-value from table {table}");
+}

src/DependencyInjection/MyWorkflow.workflow.cs

@@ -0,0 +1,18 @@
+namespace TemporalioSamples.DependencyInjection;
+
+using Temporalio.Workflows;
+
+[Workflow]
+public class MyWorkflow
+{
+    [WorkflowRun]
+    public async Task<string> RunAsync()
+    {
+        return await Workflow.ExecuteActivityAsync(
+            (MyActivities act) => act.SelectFromDatabaseAsync("some-db-table"),
+            new()
+            {
+                StartToCloseTimeout = TimeSpan.FromMinutes(5),
+            });
+    }
+}

src/DependencyInjection/Program.cs

@@ -0,0 +1,54 @@
+using Temporalio.Client;
+using Temporalio.Extensions.Hosting;
+using TemporalioSamples.DependencyInjection;
+
+async Task RunWorkerAsync()
+{
+    IHost host = Host.CreateDefaultBuilder(args)
+        .ConfigureLogging(ctx =>
+            ctx.AddSimpleConsole().SetMinimumLevel(LogLevel.Information))
+        .ConfigureServices(ctx =>
+            ctx.
+                // Add the database client at the scoped level
+                AddScoped<IMyDatabaseClient, MyDatabaseClient>().
+                // Add the worker
+                AddHostedTemporalWorker(
+                    clientTargetHost: "localhost:7233",
+                    clientNamespace: "default",
+                    taskQueue: "dependency-injection-sample").
+                // Add the activities class at the scoped level
+                AddScopedActivities<MyActivities>().
+                AddWorkflow<MyWorkflow>())
+        .Build();
+    await host.RunAsync();
+}
+
+async Task ExecuteWorkflowAsync()
+{
+    var client = await TemporalClient.ConnectAsync(new("localhost:7233")
+    {
+        LoggerFactory = LoggerFactory.Create(builder =>
+            builder.
+                AddSimpleConsole(options => options.TimestampFormat = "[HH:mm:ss] ").
+                SetMinimumLevel(LogLevel.Information)),
+    });
+
+    Console.WriteLine("Executing workflow");
+    var result = await client.ExecuteWorkflowAsync(
+        (MyWorkflow wf) => wf.RunAsync(),
+        new(id: "dependency-injection-workflow-id", taskQueue: "dependency-injection-sample"));
+
+    Console.WriteLine("Workflow result: {0}", result);
+}
+
+switch (args.ElementAtOrDefault(0))
+{
+    case "worker":
+        await RunWorkerAsync();
+        break;
+    case "workflow":
+        await ExecuteWorkflowAsync();
+        break;
+    default:
+        throw new ArgumentException("Must pass 'worker' or 'workflow' as the single argument");
+}

src/DependencyInjection/README.md

@@ -0,0 +1,14 @@
+# Dependency Injection
+
+This sample shows an activity having a dependency injected and a worker running as a generic host.
+
+To run, first see [README.md](../../README.md) for prerequisites. Then, run the following from this directory
+in a separate terminal to start the worker:
+
+    dotnet run worker
+
+Then in another terminal, run the workflow from this directory:
+
+    dotnet run workflow
+
+This will show logs in the worker window of the workflow running.

src/DependencyInjection/TemporalioSamples.DependencyInjection.csproj

@@ -0,0 +1,5 @@
+<Project Sdk="Microsoft.NET.Sdk.Worker">
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="7.0.0" />
+  </ItemGroup>
+</Project>