Add OpenTelemetry Collector extension/component

CommunityToolkit.Aspire.slnx

@@ -172,6 +172,7 @@
     <Project Path="src/CommunityToolkit.Aspire.Hosting.Ngrok/CommunityToolkit.Aspire.Hosting.Ngrok.csproj" />
     <Project Path="src/CommunityToolkit.Aspire.Hosting.NodeJS.Extensions/CommunityToolkit.Aspire.Hosting.NodeJS.Extensions.csproj" />
     <Project Path="src/CommunityToolkit.Aspire.Hosting.Ollama/CommunityToolkit.Aspire.Hosting.Ollama.csproj" />
+    <Project Path="src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector.csproj" />
     <Project Path="src/CommunityToolkit.Aspire.Hosting.PapercutSmtp/CommunityToolkit.Aspire.Hosting.PapercutSmtp.csproj" />
     <Project Path="src/CommunityToolkit.Aspire.Hosting.PostgreSQL.Extensions/CommunityToolkit.Aspire.Hosting.PostgreSQL.Extensions.csproj" />
     <Project Path="src/CommunityToolkit.Aspire.Hosting.PowerShell/CommunityToolkit.Aspire.Hosting.PowerShell.csproj" />

src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/CollectorExtensions.cs

@@ -0,0 +1,105 @@
+using Aspire.Hosting.ApplicationModel;
+using Aspire.Hosting.Lifecycle;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+
+namespace Aspire.Hosting;
+
+/// <summary>
+/// Extension methods to add the collector resource
+/// </summary>
+public static class CollectorExtensions
+{
+    private const string DashboardOtlpUrlVariableNameLegacy = "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL";
+    private const string DashboardOtlpUrlVariableName = "ASPIRE_DASHBOARD_OTLP_ENDPOINT_URL";
+    private const string DashboardOtlpApiKeyVariableName = "AppHost:OtlpApiKey";
+    private const string DashboardOtlpUrlDefaultValue = "http://localhost:18889";
+
+    /// <summary>
+    /// Adds an OpenTelemetry Collector into the Aspire AppHost
+    /// </summary>
+    /// <param name="builder"></param>
+    /// <param name="name"></param>
+    /// <param name="configureSettings"></param>
+    /// <returns></returns>
+    public static IResourceBuilder<CollectorResource> AddOpenTelemetryCollector(this IDistributedApplicationBuilder builder,
+        string name,
+        Action<OpenTelemetryCollectorSettings> configureSettings = null!)
+    {
+        var url = builder.Configuration[DashboardOtlpUrlVariableName] ??
+            builder.Configuration[DashboardOtlpUrlVariableNameLegacy] ??
+            DashboardOtlpUrlDefaultValue;
+
+        var settings = new OpenTelemetryCollectorSettings();
+        configureSettings?.Invoke(settings);
+
+        var isHttpsEnabled = !settings.ForceNonSecureReceiver && url.StartsWith("https", StringComparison.OrdinalIgnoreCase);
+
+        var dashboardOtlpEndpoint = ReplaceLocalhostWithContainerHost(url, builder.Configuration);
+
+        var resource = new CollectorResource(name);
+        var resourceBuilder = builder.AddResource(resource)
+            .WithImage(settings.CollectorImage, settings.CollectorVersion)
+            .WithEnvironment("ASPIRE_ENDPOINT", dashboardOtlpEndpoint)
+            .WithEnvironment("ASPIRE_API_KEY", builder.Configuration[DashboardOtlpApiKeyVariableName]);
+
+        if (settings.EnableGrpcEndpoint)
+            resourceBuilder.WithEndpoint(targetPort: 4317, name: CollectorResource.GRPCEndpointName, scheme: isHttpsEnabled ? "https" : "http");
+        if (settings.EnableHttpEndpoint)
+            resourceBuilder.WithEndpoint(targetPort: 4318, name: CollectorResource.HTTPEndpointName, scheme: isHttpsEnabled ? "https" : "http");
+
+
+        if (!settings.ForceNonSecureReceiver && isHttpsEnabled && builder.ExecutionContext.IsRunMode && builder.Environment.IsDevelopment())
+        {
+            DevCertHostingExtensions.RunWithHttpsDevCertificate(resourceBuilder, "HTTPS_CERT_FILE", "HTTPS_CERT_KEY_FILE", (certFilePath, certKeyPath) =>
+            {
+                if (settings.EnableHttpEndpoint)
+                {
+                    resourceBuilder.WithArgs(
+                        $@"--config=yaml:receivers::otlp::protocols::http::tls::cert_file: ""{certFilePath}""",
+                        $@"--config=yaml:receivers::otlp::protocols::http::tls::key_file: ""{certKeyPath}""");
+                }
+                if (settings.EnableGrpcEndpoint)
+                {
+                    resourceBuilder.WithArgs(
+                        $@"--config=yaml:receivers::otlp::protocols::grpc::tls::cert_file: ""{certFilePath}""",
+                        $@"--config=yaml:receivers::otlp::protocols::grpc::tls::key_file: ""{certKeyPath}""");
+                }
+            });
+        }
+        return resourceBuilder;
+    }
+
+    /// <summary>
+    /// Force all apps to forward to the collector instead of the dashboard directly
+    /// </summary>
+    /// <param name="builder"></param>
+    /// <returns></returns>
+    public static IResourceBuilder<CollectorResource> WithAppForwarding(this IResourceBuilder<CollectorResource> builder)
+    {
+        builder.ApplicationBuilder.Services.TryAddLifecycleHook<EnvironmentVariableHook>();
+        return builder;
+    }
+
+    private static string ReplaceLocalhostWithContainerHost(string value, IConfiguration configuration)
+    {
+        var hostName = configuration["AppHost:ContainerHostname"] ?? "host.docker.internal";
+
+        return value.Replace("localhost", hostName, StringComparison.OrdinalIgnoreCase)
+                    .Replace("127.0.0.1", hostName)
+                    .Replace("[::1]", hostName);
+    }
+
+    /// <summary>
+    /// Adds a config file to the collector
+    /// </summary>
+    /// <param name="builder"></param>
+    /// <param name="configPath"></param>
+    /// <returns></returns>
+    public static IResourceBuilder<CollectorResource> WithConfig(this IResourceBuilder<CollectorResource> builder, string configPath)
+    {
+        var configFileInfo = new FileInfo(configPath);
+        return builder.WithBindMount(configPath, $"/config/{configFileInfo.Name}")
+            .WithArgs($"--config=/config/{configFileInfo.Name}");
+    }
+}

src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/CollectorResource.cs

@@ -0,0 +1,23 @@
+using Aspire.Hosting.ApplicationModel;
+
+namespace Aspire.Hosting;
+
+/// <summary>
+/// The collector resource
+/// </summary>
+/// <param name="name">Name of the resource</param>
+public class CollectorResource(string name) : ContainerResource(name)
+{
+    internal static string GRPCEndpointName = "grpc";
+    internal static string HTTPEndpointName = "http";
+
+    /// <summary>
+    /// gRPC Endpoint
+    /// </summary>
+    public EndpointReference GRPCEndpoint => new(this, GRPCEndpointName);
+
+    /// <summary>
+    /// HTTP Endpoint
+    /// </summary>
+    public EndpointReference HTTPEndpoint => new(this, HTTPEndpointName);
+}

src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>An Aspire component to add an OpenTelemetry Collector into the OTLP pipeline</Description>
+    <AdditionalPackageTags>opentelemetry observability</AdditionalPackageTags>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Aspire.Hosting" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="$(SharedDir)\DevCertHostingExtensions.cs" Link="Utils\DevCertHostingExtensions.cs" />
+  </ItemGroup>
+
+</Project>

src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/EnvironmentVariableHook.cs

@@ -0,0 +1,58 @@
+using Aspire.Hosting.ApplicationModel;
+using Aspire.Hosting.Lifecycle;
+using Microsoft.Extensions.Logging;
+
+namespace Aspire.Hosting;
+
+/// <summary>
+/// Hooks to add the OTLP environment variables to the various containers
+/// </summary>
+/// <param name="logger"></param>
+public class EnvironmentVariableHook(ILogger<EnvironmentVariableHook> logger) : IDistributedApplicationLifecycleHook
+{
+    /// <inheritdoc />
+    public Task AfterEndpointsAllocatedAsync(DistributedApplicationModel appModel, CancellationToken cancellationToken)
+    {
+        var resources = appModel.GetProjectResources();
+        var collectorResource = appModel.Resources.OfType<CollectorResource>().FirstOrDefault();
+
+        if (collectorResource is null)
+        {
+            logger.LogWarning("No collector resource found");
+            return Task.CompletedTask;
+        }
+
+        var grpcEndpoint = collectorResource!.GetEndpoint(collectorResource!.GRPCEndpoint.EndpointName);
+        var httpEndpoint = collectorResource!.GetEndpoint(collectorResource!.HTTPEndpoint.EndpointName);
+
+        if (!resources.Any())
+        {
+            logger.LogInformation("No resources to add Environment Variables to");
+        }
+
+        foreach (var resourceItem in resources)
+        {
+            logger.LogDebug("Forwarding Telemetry for {name} to the collector", resourceItem.Name);
+            if (resourceItem is null) continue;
+
+            resourceItem.Annotations.Add(new EnvironmentCallbackAnnotation((EnvironmentCallbackContext context) =>
+            {
+                var protocol = context.EnvironmentVariables.GetValueOrDefault("OTEL_EXPORTER_OTLP_PROTOCOL", "");
+                var endpoint = protocol.ToString() == "http/protobuf" ? httpEndpoint : grpcEndpoint;
+
+                if (endpoint == null)
+                {
+                    logger.LogWarning("No {protocol} endpoint on the collector for {resourceName} to use",
+                        protocol, resourceItem.Name);
+                    return;
+                }
+
+                if (context.EnvironmentVariables.ContainsKey("OTEL_EXPORTER_OTLP_ENDPOINT"))
+                    context.EnvironmentVariables.Remove("OTEL_EXPORTER_OTLP_ENDPOINT");
+                context.EnvironmentVariables.Add("OTEL_EXPORTER_OTLP_ENDPOINT", endpoint.Url);
+            }));
+        }
+
+        return Task.CompletedTask;
+    }
+}

src/CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector/OpenTelemetryCollectorSettings.cs

@@ -0,0 +1,36 @@
+namespace Aspire.Hosting;
+
+/// <summary>
+/// Settings for the OpenTelemetry Collector
+/// </summary>
+public class OpenTelemetryCollectorSettings
+{
+    /// <summary>
+    /// The version of the collector, defaults to latest
+    /// </summary>
+    public string CollectorVersion { get; set; } = "latest";
+
+    /// <summary>
+    /// The image of the collector, defaults to ghcr.io/open-telemetry/opentelemetry-collector-releases/opentelemetry-collector-contrib
+    /// </summary>
+    public string CollectorImage { get; set; } = "ghcr.io/open-telemetry/opentelemetry-collector-releases/opentelemetry-collector-contrib";
+
+    /// <summary>
+    /// Force the default OTLP receivers in the collector to use HTTP even if Aspire is set to HTTPS
+    /// </summary>
+    public bool ForceNonSecureReceiver { get; set; } = false;
+
+    /// <summary>
+    /// Enable the gRPC endpoint on the collector container (requires the relevant collector config)
+    /// 
+    /// Note: this will also setup SSL if Aspire is configured for HTTPS
+    /// </summary>
+    public bool EnableGrpcEndpoint { get; set; } = true;
+
+    /// <summary>
+    /// Enable the HTTP endpoint on the collector container (requires the relevant collector config)
+    /// 
+    /// Note: this will also setup SSL if Aspire is configured for HTTPS
+    /// </summary>
+    public bool EnableHttpEndpoint { get; set; } = true;
+}