Update metrics sample to use OTLP and OTEL collector

samples/Metrics/MetricsApp.AppHost/MetricsApp.AppHost.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <Sdk Name="Aspire.AppHost.Sdk" Version="9.0.0" />
 

samples/Metrics/MetricsApp.AppHost/OpenTelemetryCollector/CollectorLifecycleHook.cs

@@ -0,0 +1,54 @@
+using Aspire.Hosting.Lifecycle;
+using Microsoft.Extensions.Logging;
+
+namespace MetricsApp.AppHost.OpenTelemetryCollector;
+
+internal sealed class CollectorLifecycleHook : IDistributedApplicationLifecycleHook
+{
+    private readonly ILogger<CollectorLifecycleHook> _logger;
+
+    public CollectorLifecycleHook(ILogger<CollectorLifecycleHook> logger)
+    {
+        _logger = logger;
+    }
+
+    public Task AfterEndpointsAllocatedAsync(DistributedApplicationModel appModel, CancellationToken cancellationToken)
+    {
+        var resources = appModel.GetProjectResources();
+        var collectorResource = appModel.Resources.OfType<CollectorResource>().FirstOrDefault();
+
+        if (collectorResource == null)
+        {
+            _logger.LogWarning("No collector resource found");
+            return Task.CompletedTask;
+        }
+
+        var endpoint = collectorResource.GetEndpoint(CollectorResource.OtlpGrpcEndpointName);
+        if (endpoint == null)
+        {
+            _logger.LogWarning("No endpoint for the collector");
+            return Task.CompletedTask;
+        }
+
+        if (resources.Count() == 0)
+        {
+            _logger.LogInformation("No resources to add Environment Variables to");
+        }
+
+        foreach (var resourceItem in resources)
+        {
+            _logger.LogDebug($"Forwarding Telemetry for {resourceItem.Name} to the collector");
+            if (resourceItem == null)
+            {
+                continue;
+            }
+
+            resourceItem.Annotations.Add(new EnvironmentCallbackAnnotation((EnvironmentCallbackContext context) =>
+            {
+                context.EnvironmentVariables["OTEL_EXPORTER_OTLP_ENDPOINT"] = endpoint;
+            }));
+        }
+
+        return Task.CompletedTask;
+    }
+}

samples/Metrics/MetricsApp.AppHost/OpenTelemetryCollector/CollectorResource.cs

@@ -0,0 +1,7 @@
+namespace MetricsApp.AppHost.OpenTelemetryCollector;
+
+public class CollectorResource(string name) : ContainerResource(name)
+{
+    internal const string OtlpGrpcEndpointName = "grpc";
+    internal const string OtlpHttpEndpointName = "http";
+}

samples/Metrics/MetricsApp.AppHost/OpenTelemetryCollector/CollectorResourceBuilderExtensions.cs

@@ -0,0 +1,39 @@
+using Microsoft.Extensions.Configuration;
+
+namespace MetricsApp.AppHost.OpenTelemetryCollector;
+
+public static class CollectorResourceBuilderExtensions
+{
+    private const string DashboardOtlpUrlVariableName = "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL";
+    private const string DashboardOtlpApiKeyVariableName = "AppHost:OtlpApiKey";
+    private const string DashboardOtlpUrlDefaultValue = "http://localhost:18889";
+
+    public static IResourceBuilder<CollectorResource> AddCollector(this IDistributedApplicationBuilder builder, string name, string configFileLocation)
+    {
+        builder.AddCollectorInfrastructure();
+
+        var url = builder.Configuration[DashboardOtlpUrlVariableName] ?? DashboardOtlpUrlDefaultValue;
+
+        var dashboardOtlpEndpoint = ReplaceLocalhostWithContainerHost(url, builder.Configuration);
+        var dashboardInsecure = url.StartsWith("https", StringComparison.OrdinalIgnoreCase) ? "false" : "true";
+
+        var resource = new CollectorResource(name);
+        return builder.AddResource(resource)
+            .WithImage("ghcr.io/open-telemetry/opentelemetry-collector-releases/opentelemetry-collector-contrib", "latest")
+            .WithEndpoint(port: 4317, targetPort: 4317, name: CollectorResource.OtlpGrpcEndpointName, scheme: "http")
+            .WithEndpoint(port: 4318, targetPort: 4318, name: CollectorResource.OtlpHttpEndpointName, scheme: "http")
+            .WithBindMount(configFileLocation, "/etc/otelcol-contrib/config.yaml")
+            .WithEnvironment("ASPIRE_ENDPOINT", dashboardOtlpEndpoint)
+            .WithEnvironment("ASPIRE_API_KEY", builder.Configuration[DashboardOtlpApiKeyVariableName])
+            .WithEnvironment("ASPIRE_INSECURE", dashboardInsecure);
+    }
+
+    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);
+    }
+}

samples/Metrics/MetricsApp.AppHost/OpenTelemetryCollector/CollectorServiceExtensions.cs

@@ -0,0 +1,13 @@
+using Aspire.Hosting.Lifecycle;
+
+namespace MetricsApp.AppHost.OpenTelemetryCollector;
+
+internal static class CollectorServiceExtensions
+{
+    public static IDistributedApplicationBuilder AddCollectorInfrastructure(this IDistributedApplicationBuilder builder)
+    {
+        builder.Services.TryAddLifecycleHook<CollectorLifecycleHook>();
+
+        return builder;
+    }
+}

samples/Metrics/MetricsApp.AppHost/OpenTelemetryCollector/README.md

@@ -0,0 +1,3 @@
+# Aspire Hosting extension for the OpenTelemetry Collector
+
+Based on source from https://github.com/practical-otel/opentelemetry-aspire-collector by @martinjt.

samples/Metrics/MetricsApp.AppHost/Program.cs

@@ -1,17 +1,24 @@
-var builder = DistributedApplication.CreateBuilder(args);
+using MetricsApp.AppHost.OpenTelemetryCollector;
+
+var builder = DistributedApplication.CreateBuilder(args);
+
+var prometheus = builder.AddContainer("prometheus", "prom/prometheus")
+       .WithBindMount("../prometheus", "/etc/prometheus", isReadOnly: true)
+       .WithArgs("--web.enable-otlp-receiver", "--config.file=/etc/prometheus/prometheus.yml")
+       .WithHttpEndpoint(targetPort: 9090, name: "http");
 
 var grafana = builder.AddContainer("grafana", "grafana/grafana")
                      .WithBindMount("../grafana/config", "/etc/grafana", isReadOnly: true)
                      .WithBindMount("../grafana/dashboards", "/var/lib/grafana/dashboards", isReadOnly: true)
+                     .WithEnvironment(c => c.EnvironmentVariables["PROMETHEUS_PORT"] = $"{prometheus.GetEndpoint("http").Port}")
                      .WithHttpEndpoint(targetPort: 3000, name: "http");
 
+builder.AddCollector("otelcollector", "../otelcollector/config.yaml")
+       .WithEnvironment("PROMETHEUS_ENDPOINT", $"{prometheus.GetEndpoint("http")}/api/v1/otlp");
+
 builder.AddProject<Projects.MetricsApp>("app")
        .WithEnvironment("GRAFANA_URL", grafana.GetEndpoint("http"));
 
-builder.AddContainer("prometheus", "prom/prometheus")
-       .WithBindMount("../prometheus", "/etc/prometheus", isReadOnly: true)
-       .WithHttpEndpoint(/* This port is fixed as it's referenced from the Grafana config */ port: 9090, targetPort: 9090);
-
 using var app = builder.Build();
 
 await app.RunAsync();

samples/Metrics/MetricsApp.AppHost/Properties/launchSettings.json

@@ -22,7 +22,8 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:19032",
-        "DOTNET_RESOURCE_SERVICE_ENDPOINT_URL": "http://localhost:20132"
+        "DOTNET_RESOURCE_SERVICE_ENDPOINT_URL": "http://localhost:20132",
+        "ASPIRE_ALLOW_UNSECURED_TRANSPORT": "true"
       }
     },
     "generate-manifest": {

samples/Metrics/ServiceDefaults/Extensions.cs

@@ -66,11 +66,6 @@ private static IHostApplicationBuilder AddOpenTelemetryExporters(this IHostAppli
             builder.Services.AddOpenTelemetry().UseOtlpExporter();
         }
 
-        // The following lines enable the Prometheus exporter (requires the OpenTelemetry.Exporter.Prometheus.AspNetCore package)
-        builder.Services.AddOpenTelemetry()
-            // BUG: Part of the workaround for https://github.com/open-telemetry/opentelemetry-dotnet-contrib/issues/1617
-           .WithMetrics(metrics => metrics.AddPrometheusExporter(options => options.DisableTotalNameSuffixForCounters = true));
-
         return builder;
     }
 
@@ -85,9 +80,6 @@ public static IHostApplicationBuilder AddDefaultHealthChecks(this IHostApplicati
 
     public static WebApplication MapDefaultEndpoints(this WebApplication app)
     {
-        // The following line enables the Prometheus endpoint (requires the OpenTelemetry.Exporter.Prometheus.AspNetCore package)
-        app.MapPrometheusScrapingEndpoint();
-
         // Adding health checks endpoints to applications in non-development environments has security implications.
         // See https://aka.ms/dotnet/aspire/healthchecks for details before enabling these endpoints in non-development environments.
         if (app.Environment.IsDevelopment())

samples/Metrics/grafana/config/provisioning/datasources/default.yaml

@@ -5,5 +5,5 @@ datasources:
     type: prometheus
     access: proxy
     # Access mode - proxy (server in the UI) or direct (browser in the UI).
-    url: http://host.docker.internal:9090
+    url: http://host.docker.internal:$PROMETHEUS_PORT
     uid: PBFA97CFB590B2093

samples/Metrics/otelcollector/config.yaml

@@ -0,0 +1,42 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+        endpoint: 0.0.0.0:4317
+      http:
+        endpoint: 0.0.0.0:4318
+
+processors:
+  batch:
+
+exporters:
+  debug:
+    verbosity: detailed
+  otlp/aspire:
+    endpoint: ${env:ASPIRE_ENDPOINT}
+    headers:
+      x-otlp-api-key: ${env:ASPIRE_API_KEY}
+    tls:
+        insecure: ${env:ASPIRE_INSECURE}
+        insecure_skip_verify: true
+  otlphttp/prometheus:
+    endpoint: ${env:PROMETHEUS_ENDPOINT}
+    tls:
+        insecure: true
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp/aspire]
+    metrics:
+      receivers: [otlp]
+      processors: [batch]
+      exporters:
+        - otlp/aspire
+        - otlphttp/prometheus
+    logs:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp/aspire]

samples/Metrics/prometheus/prometheus.yml

@@ -1,7 +1,5 @@
-global:
-  scrape_interval: 1s # makes for a good demo
+storage:
+  tsdb:
+    out_of_order_time_window: 30m
 
-scrape_configs:
-  - job_name: 'metricsapp'
-    static_configs:
-      - targets: ['host.docker.internal:5048'] # hard-coded port matches launchSettings.json
+otlp: