Add OpenTelemetry support

WhatsApp.sln

@@ -7,10 +7,16 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WhatsApp", "src\WhatsApp\Wh
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tests", "src\Tests\Tests.csproj", "{A2E143CF-3BCF-4E9F-A278-9DF65D8CC609}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sample", "src\Sample\Sample.csproj", "{37A61B10-BE1C-476D-81E0-2D0BCEAF3EE7}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sample", "src\SampleApp\Sample\Sample.csproj", "{37A61B10-BE1C-476D-81E0-2D0BCEAF3EE7}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CodeAnalysis", "src\CodeAnalysis\CodeAnalysis.csproj", "{63583965-B86B-485E-AACF-5C4E453B182E}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Dashboard", "src\SampleApp\Dashboard\Dashboard.csproj", "{1D9F1134-3631-4C5E-AF53-FBAB254BCECC}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "SampleApp", "SampleApp", "{02EA681E-C7D8-13C7-8484-4AC65E1B71E8}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ServiceDefaults", "src\SampleApp\ServiceDefaults\ServiceDefaults.csproj", "{65B20A16-5D87-220C-1765-336D9F7A0840}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -33,10 +39,23 @@ Global
 		{63583965-B86B-485E-AACF-5C4E453B182E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{63583965-B86B-485E-AACF-5C4E453B182E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{63583965-B86B-485E-AACF-5C4E453B182E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1D9F1134-3631-4C5E-AF53-FBAB254BCECC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1D9F1134-3631-4C5E-AF53-FBAB254BCECC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1D9F1134-3631-4C5E-AF53-FBAB254BCECC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1D9F1134-3631-4C5E-AF53-FBAB254BCECC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{65B20A16-5D87-220C-1765-336D9F7A0840}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{65B20A16-5D87-220C-1765-336D9F7A0840}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{65B20A16-5D87-220C-1765-336D9F7A0840}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{65B20A16-5D87-220C-1765-336D9F7A0840}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{37A61B10-BE1C-476D-81E0-2D0BCEAF3EE7} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
+		{1D9F1134-3631-4C5E-AF53-FBAB254BCECC} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
+		{65B20A16-5D87-220C-1765-336D9F7A0840} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
+	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {682FF84E-D387-4800-B5A5-BEDD33C6C462}
 	EndGlobalSection

readme.md

@@ -140,6 +140,36 @@ corresponding access token for it. To get a permanent access token for
 use, you'd need to create a [system user](https://business.facebook.com/latest/settings/system_users) 
 with full control permissions to the WhatsApp Business API (app).
 
+## Functionality pipelines
+
+`IWhatsAppHandler` instances can be layered to form a pipeline of components, each 
+contributing unique capabilities. These components may originate from `Devlooped.WhatsApp`, 
+external NuGet libraries, or custom implementations. This mechanism enables flexible 
+enhancement of the WhatsApp handler's functionality to suit specific requirements. 
+Below is an example that wraps a WhatsApp handler with logging and OpenTelemetry tracing:
+
+```csharp
+var builder = FunctionsApplication.CreateBuilder(args);
+builder.ConfigureFunctionsWebApplication();
+
+builder.Services.AddWhatsApp<MyWhatsAppHandler>()
+    .UseOpenTelemetry(builder.Environment.ApplicationName)
+    .UseLogging();
+
+builder.Build().Run();
+```
+
+### OpenTelemetry
+
+The configurable built-in support for OpenTelemetry shown above allows tracking 
+of key metrics such as message processing time and the number of messages processed.
+
+This is a rendering of the telemetry data in Aspire in the sample app provided in 
+this repository:
+
+![](https://raw.githubusercontent.com/devlooped/WhatsApp/main/assets/img/aspire.png)
+
+
 ## Scalability and Performance
 
 In order to quickly and efficiently process incoming messages, the library uses 

src/SampleApp/Dashboard/Dashboard.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <Sdk Name="Aspire.AppHost.Sdk" Version="9.0.0" />
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <IsAspireHost>true</IsAspireHost>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Aspire.Hosting.AppHost" Version="9.3.0" />
+    <PackageReference Include="Aspire.Hosting.Azure.Functions" Version="9.3.0-preview.1.25265.20" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Sample\Sample.csproj" />
+    <ProjectReference Include="..\ServiceDefaults\ServiceDefaults.csproj" />
+  </ItemGroup>
+
+</Project>

src/SampleApp/Dashboard/Program.cs

@@ -0,0 +1,15 @@
+var builder = DistributedApplication.CreateBuilder(args);
+
+builder.AddAzureFunctionsProject<Projects.Sample>("api")
+       // Functions App will launch with default port, not the launchSettings.json port
+       // So we request a proxy to forward 4242 to the default function app port instead.
+       // This will only work if you have a single Function App.
+       // See https://github.com/dotnet/aspire/issues/8589
+       //.WithArgs("--port", "4242")
+       .WithHttpEndpoint(4242, 7071, "apiproxy")
+       .WithEnvironment("AzureWebJobsStorage", "UseDevelopmentStorage=true")
+       // Disable Azure SDK telemetry since we're running locally
+       .WithEnvironment("AZURE_SDK_TELEMETRY_ENABLED", "false")
+       .WithExternalHttpEndpoints();
+
+builder.Build().Run();

src/SampleApp/Dashboard/Properties/launchSettings.json

@@ -0,0 +1,36 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:17138;http://localhost:15084",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+        "DOTNET_ENVIRONMENT": "Development",
+        "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "https://localhost:21125",
+        "DOTNET_RESOURCE_SERVICE_ENDPOINT_URL": "https://localhost:22233"
+      }
+    },
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:15084",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+        "DOTNET_ENVIRONMENT": "Development",
+        "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:19081",
+        "DOTNET_RESOURCE_SERVICE_ENDPOINT_URL": "http://localhost:20124"
+      }
+    },
+    "Sample": {
+      "commandName": "Project",
+      "commandLineArgs": "--port 4242",
+      "applicationUrl": "http://localhost:4242",
+      "dotnetRunMessages": true,
+      "launchBrowser": false
+    }
+  }
+}

src/SampleApp/Dashboard/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

src/SampleApp/Dashboard/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning",
+      "Aspire.Hosting.Dcp": "Warning"
+    }
+  }
+}

src/SampleApp/Dashboard/otel.yaml

@@ -0,0 +1,5 @@
+processors:
+  filter/healthcheck:
+    traces:
+      span:
+        - 'attributes["http.target"] == "/healthcheck"'

src/Sample/Program.cs → src/SampleApp/Sample/Program.cs

@@ -9,6 +9,7 @@
 
 var builder = FunctionsApplication.CreateBuilder(args);
 builder.ConfigureFunctionsWebApplication();
+builder.AddServiceDefaults();
 
 #if DEBUG
 builder.Environment.EnvironmentName = "Development";
@@ -33,8 +34,9 @@
 });
 
 builder.Services
-    .AddWhatsApp<IWhatsAppClient, ILogger<Program>, JsonSerializerOptions>(async (client, logger, options, message, cancellation) =>
+    .AddWhatsApp<IWhatsAppClient, ILogger<Program>, JsonSerializerOptions>(async (client, logger, options, messages, cancellation) =>
     {
+        var message = messages.Last();
         logger.LogInformation("💬 Received message: {Message}", message);
 
         if (message is ErrorMessage error)
@@ -95,6 +97,8 @@ await client.ReplyAsync(content, $"☑️ Got your {content.Content.Type}:\r\n{J
             return;
         }
     })
+    // Matches what we use in ConfigureOpenTelemetry
+    .UseOpenTelemetry(builder.Environment.ApplicationName)
     .UseLogging();
 
 builder.Build().Run();

src/Sample/Properties/launchSettings.json → src/SampleApp/Sample/Properties/launchSettings.json

@@ -3,6 +3,8 @@
     "Sample": {
       "commandName": "Project",
       "commandLineArgs": "--port 4242",
+      "applicationUrl": "http://localhost:4242",
+      "dotnetRunMessages": true,
       "launchBrowser": false
     }
   }

src/Sample/Sample.csproj → src/SampleApp/Sample/Sample.csproj

@@ -1,20 +1,32 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
-    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
     <OutputType>Exe</OutputType>
+    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
+    <FunctionsWorkerRuntime>dotnet-isolated</FunctionsWorkerRuntime>
   </PropertyGroup>
   <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
+    <PackageReference Include="Azure.Monitor.OpenTelemetry.AspNetCore" Version="1.3.0" />
+    <PackageReference Include="DistributedCache.AzureTableStorage" Version="3.3.0" />
     <!-- Application Insights isn't enabled by default. See https://aka.ms/AAt8mw4. -->
     <!-- <PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.22.0" /> -->
     <!-- <PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="2.0.0" /> -->
     <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="2.0.0" />
     <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="2.0.1" />
     <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="2.0.2" />
+    <PackageReference Include="Microsoft.Extensions.Http.Resilience" Version="9.5.0" />
+    <PackageReference Include="Microsoft.Extensions.ServiceDiscovery" Version="9.3.0" />
+    <PackageReference Include="OpenTelemetry.Exporter.Console" Version="1.12.0" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.12.0" />
+    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.12.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.12.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.12.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.12.0" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\WhatsApp\WhatsApp.csproj" />
+    <ProjectReference Include="..\..\WhatsApp\WhatsApp.csproj" />
+    <ProjectReference Include="..\ServiceDefaults\ServiceDefaults.csproj" />
   </ItemGroup>
   <ItemGroup>
     <None Update="host.json" CopyToOutputDirectory="PreserveNewest" />
@@ -23,4 +35,4 @@
   <ItemGroup>
     <Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
   </ItemGroup>
-</Project>
+</Project>

src/Sample/host.json → src/SampleApp/Sample/host.json

@@ -16,6 +16,8 @@
     "logLevel": {
       "default": "Warning",
       "Function": "Trace",
+      "Azure": "Warning",
+      "Azure.Core": "Error",
       "Microsoft": "Warning",
       "System": "Warning"
     }