Add samples for external clients

DurableTask.Netherite.sln

@@ -41,7 +41,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TokenCredentialDF", "sample
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TokenCredentialDTFx", "samples\TokenCredentialDTFx\TokenCredentialDTFx.csproj", "{FBFF0814-E6C0-489A-ACCF-9D0699219621}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Functions.Worker.Extensions.DurableTask.Netherite", "src\Functions.Worker.Extensions.DurableTask.Netherite\Functions.Worker.Extensions.DurableTask.Netherite.csproj", "{3E17402B-3F65-4E5B-B752-48AD56B81208}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Functions.Worker.Extensions.DurableTask.Netherite", "src\Functions.Worker.Extensions.DurableTask.Netherite\Functions.Worker.Extensions.DurableTask.Netherite.csproj", "{3E17402B-3F65-4E5B-B752-48AD56B81208}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "StandaloneClient", "samples\StandaloneClient\StandaloneClient.csproj", "{CC543A91-1815-4192-88EB-89C892652ACB}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -97,6 +99,10 @@ Global
 		{3E17402B-3F65-4E5B-B752-48AD56B81208}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3E17402B-3F65-4E5B-B752-48AD56B81208}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3E17402B-3F65-4E5B-B752-48AD56B81208}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CC543A91-1815-4192-88EB-89C892652ACB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CC543A91-1815-4192-88EB-89C892652ACB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CC543A91-1815-4192-88EB-89C892652ACB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CC543A91-1815-4192-88EB-89C892652ACB}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -114,6 +120,7 @@ Global
 		{B99AB043-47DC-467C-93CB-D6C69D3B1AD4} = {AB958467-9236-402E-833C-B8DE4841AB9F}
 		{FBFF0814-E6C0-489A-ACCF-9D0699219621} = {AB958467-9236-402E-833C-B8DE4841AB9F}
 		{3E17402B-3F65-4E5B-B752-48AD56B81208} = {D33AB157-04B9-4BAD-B580-C3C87C17828C}
+		{CC543A91-1815-4192-88EB-89C892652ACB} = {AB958467-9236-402E-833C-B8DE4841AB9F}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {238A9613-5411-41CF-BDEC-168CCD5C03FB}

samples/StandaloneClient/FunctionsStartup.cs

@@ -0,0 +1,90 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// Reference: https://docs.microsoft.com/en-us/azure/azure-functions/functions-dotnet-dependency-injection
+[assembly: Microsoft.Azure.Functions.Extensions.DependencyInjection.FunctionsStartup(typeof(StandaloneClient.Startup))]
+namespace StandaloneClient
+{
+    using System;
+    using System.Collections.Generic;
+    using Azure.Identity;
+    using DurableTask.Netherite;
+    using DurableTask.Netherite.AzureFunctions;
+    using Microsoft.Azure.Functions.Extensions.DependencyInjection;
+    using Microsoft.Azure.WebJobs;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask.ContextImplementations;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask.Options;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask;
+    using Microsoft.Extensions.DependencyInjection;
+    using Microsoft.Extensions.DependencyInjection.Extensions;
+    using Microsoft.Extensions.Logging;
+    using Microsoft.Extensions.Options;
+    using System.Linq;
+    using Castle.Core.Logging;
+
+    public class Startup : FunctionsStartup
+    {
+        public override void Configure(IFunctionsHostBuilder builder)
+        {
+            builder.Services.AddSingleton<ExternalClientFactory>();
+        }
+
+        public class ExternalClientFactory
+        {
+            readonly DurableClientFactory configuredClientFactory;
+            readonly string defaultHubName;
+            readonly string defaultConnectionName;
+            readonly bool isEmulation;
+
+            const string DefaultStorageProviderName = "AzureStorage";
+            const string DefaultStorageConnectionName = "AzureWebJobsStorage";
+
+            public ExternalClientFactory(
+                IOptions<DurableClientOptions> durableClientOptions,
+                IOptions<DurableTaskOptions> durableTaskOptions,
+                Microsoft.Extensions.Logging.ILoggerFactory loggerFactory, 
+                IServiceProvider serviceProvider)
+            {
+                // determine the name of the configured storage provider
+                bool storageTypeIsConfigured = durableTaskOptions.Value.StorageProvider.TryGetValue("type", out object storageType);
+                string storageProviderName = "AzureStorage"; // default storage provider name
+                if (storageTypeIsConfigured)
+                {
+                    storageProviderName = storageType.ToString();
+                }
+
+                // find the provider factory for the configured storage provider
+                IEnumerable<IDurabilityProviderFactory> providerFactories = serviceProvider.GetServices<IDurabilityProviderFactory>();
+                IDurabilityProviderFactory providerFactory = providerFactories.First(f => string.Equals(f.Name, storageProviderName, StringComparison.OrdinalIgnoreCase));
+
+                // create the client factory
+                this.configuredClientFactory = new DurableClientFactory(durableClientOptions, durableTaskOptions, providerFactory, loggerFactory);
+
+                // determine the default hub name based on the configuration
+                this.defaultHubName = durableTaskOptions.Value.HubName;
+
+                // determine the default connection name based on the configuration
+                if (durableTaskOptions.Value.StorageProvider.TryGetValue("StorageConnectionName", out object value))
+                {
+                    this.defaultConnectionName = value.ToString();
+                }
+                else
+                {
+                    this.defaultConnectionName = DefaultStorageConnectionName;
+                }
+            }
+
+            public IDurableClient GetClient(string connectionName = null, string hubName = null)
+            {
+                var clientOptions = new DurableClientOptions() {
+                    ConnectionName = connectionName ?? this.defaultConnectionName, 
+                    TaskHub = hubName ?? this.defaultHubName, 
+                    IsExternalClient = true,
+                };
+
+                var client = this.configuredClientFactory.CreateClient(clientOptions);
+                return client;
+            }
+        }
+    }
+}

samples/StandaloneClient/Properties/launchSettings.json

@@ -0,0 +1,9 @@
+{
+  "profiles": {
+    "ExternalClient": {
+      "commandName": "Project",
+      "commandLineArgs": "--port 7135",
+      "launchBrowser": false
+    }
+  }
+}

samples/StandaloneClient/README.md

@@ -0,0 +1,17 @@
+# Standalone DF client
+
+This sample demonstrates how to create a standalone durable client.
+
+This client is constructed in a function app that is separate from the function app that runs the task hub. 
+
+It is meant to be used in conjunction with the HelloDF sample which defines the orchestration that is being executed.
+
+## How to run it
+
+1. Set the environment variable EventHubsConnection to contain a connection string for an event hubs namespace. You cannot use emulation for creating a standalone client.
+
+2. Start the HelloDF sample app so it runs the task hub. Keep this running (and watch for error messages in the log).
+
+3. In a second window, start this app (StandaloneDFClient). Keep it running (and watch for error messages in the log).
+
+4. Issue an HTTP request to the standalone client, like `curl http://localhost:7135/test`. You should receive (possibly after a few seconds) a return message saying 'client successfully started the instance'.

samples/StandaloneClient/StandaloneClient.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.1.3" />
+	<PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0" />
+	<PackageReference Include="Microsoft.Azure.DurableTask.Netherite.AzureFunctions" Version="1.3.0" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Update="host.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+    <None Update="local.settings.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
+    </None>
+  </ItemGroup>
+</Project>

samples/StandaloneClient/Test.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace StandaloneClient
+{
+    using System;
+    using System.Threading.Tasks;
+    using System.Net;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.Azure.WebJobs;
+    using Microsoft.Azure.WebJobs.Extensions.Http;
+    using Microsoft.AspNetCore.Http;
+    using Microsoft.Extensions.Options;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask.ContextImplementations;
+    using Microsoft.Azure.WebJobs.Extensions.DurableTask.Options;
+    using static StandaloneClient.Startup;
+
+    public class Test
+    {
+        readonly ExternalClientFactory externalClientFactory;
+
+        public Test(ExternalClientFactory externalClientFactory)
+        {
+            this.externalClientFactory = externalClientFactory;
+        }
+
+        [FunctionName(nameof(Test))]
+        public async Task<IActionResult> Run(
+            [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = null)] HttpRequest req)
+        {
+            try
+            {
+                var client = this.externalClientFactory.GetClient();
+                string orchestrationInstanceId = await client.StartNewAsync("HelloSequence");
+                return new OkObjectResult($"client successfully started the instance {orchestrationInstanceId}.\n");
+            }
+            catch (Exception e)
+            {
+                return new ObjectResult($"exception: {e}") { StatusCode = (int)HttpStatusCode.InternalServerError };
+            }
+        }
+    }
+}

samples/StandaloneClient/host.json

@@ -0,0 +1,14 @@
+{
+  "version": "2.0",
+  "extensions": {
+    "http": {
+      "routePrefix": ""
+    },
+    "durableTask": {
+      "hubName": "hello",
+      "storageProvider": {
+        "type": "Netherite"
+      }
+    }
+  }
+}

samples/StandaloneClient/local.settings.json

@@ -0,0 +1,7 @@
+{
+  "IsEncrypted": false,
+  "Values": {
+    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
+    "FUNCTIONS_WORKER_RUNTIME": "dotnet"
+  }
+}