add the quotetext endpoint that makes an http request to test nested …

…traces

.vscode/settings.json

@@ -10,6 +10,7 @@
         "otlp",
         "Petroski",
         "Pravin",
+        "quotetext",
         "Sipley",
         "Skroob",
         "Spaceballs",

README.md

@@ -45,10 +45,32 @@ http \
 # make a request that includes a parent trace.
 # NB the dotnet trace id will be set to the traceparent trace id.
 # NB the tracestate does not seem to be stored or propagated anywhere.
+# NB traceparent syntax: <version>-<trace-id>-<parent-id-aka-span-id>-<trace-flags>
 http \
   --verbose \
   http://localhost:8000/quote \
-  traceparent:00-f1f1f1f1f1f1f1f1f1f1f1f1f1f1f1f1-2f2f2f2f2f2f2f2f-01 \
+  traceparent:00-10000000000000000000000000000000-1000000000000000-01 \
+  tracestate:x.client.state=example
+
+# make a request to quotetext, which in turn, makes a nested request to quote.
+http \
+  --verbose \
+  http://localhost:8000/quotetext
+
+# make a failing request to quotetext, which in turn, makes a nested failing
+# request to quote.
+http \
+  --verbose \
+  http://localhost:8000/quotetext?opsi=opsi
+
+# make a request that includes a parent trace.
+# NB the dotnet trace id will be set to the traceparent trace id.
+# NB the tracestate does not seem to be stored or propagated anywhere.
+# NB traceparent syntax: <version>-<trace-id>-<parent-id-aka-span-id>-<trace-flags>
+http \
+  --verbose \
+  http://localhost:8000/quotetext \
+  traceparent:00-20000000000000000000000000000000-1000000000000000-01 \
   tracestate:x.client.state=example
 
 # open aspire dashboard (metrics/traces/logs).

docker-compose.yml

@@ -22,6 +22,7 @@ services:
       - OTEL_EXPORTER_OTLP_ENDPOINT=http://aspire-dashboard:18889
       - OTEL_EXPORTER_OTLP_PROTOCOL=grpc
       - ASPNETCORE_URLS=http://+:8000
+      - QUOTES_BASE_URL=http://quotes:8000
     ports:
       # http api.
       # http://localhost:8000

quotes/Controllers/QuoteTextController.cs

@@ -0,0 +1,43 @@
+namespace Quotes.Controllers;
+
+using Microsoft.AspNetCore.Http.Features;
+using Microsoft.AspNetCore.Mvc;
+
+[ApiController]
+[Route("[controller]")]
+public class QuoteTextController : ControllerBase
+{
+    private readonly ILogger<QuoteController> _logger;
+    private readonly IHttpClientFactory _httpClientFactory;
+
+    public QuoteTextController(ILogger<QuoteController> logger, IHttpClientFactory httpClientFactory)
+    {
+        _logger = logger;
+        _httpClientFactory = httpClientFactory;
+    }
+
+    [HttpGet(Name = "GetQuoteText")]
+    public async Task<string> GetQuoteText([FromQuery] string? opsi)
+    {
+        _logger.LogInformation("At GetQuoteText");
+
+        var activity = HttpContext.Features.Get<IHttpActivityFeature>()?.Activity;
+
+        activity?.SetTag("x.foo", "bar");
+
+        _logger.LogInformation("Current Activity Id={activityId} TraceId={traceId} SpanId={spanId}", activity?.Id, activity?.TraceId, activity?.SpanId);
+
+        var requestUrl = string.IsNullOrEmpty(opsi) ? "quote" : $"quote?opsi={Uri.EscapeDataString(opsi)}";
+
+        using var client = _httpClientFactory.CreateClient("quotes");
+
+        var quote = await client.GetFromJsonAsync<Quote>(requestUrl);
+
+        if (quote == null)
+        {
+            throw new ApplicationException("failed to get quote");
+        }
+
+        return $"{quote.Text} -- {quote.Author}";
+    }
+}

quotes/Program.cs

@@ -11,6 +11,17 @@
 builder.Services.AddControllers();
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
+builder.Services.AddHttpClient(
+    "quotes",
+    client =>
+    {
+        var quotesBaseUrl = Environment.GetEnvironmentVariable("QUOTES_BASE_URL");
+        if (string.IsNullOrEmpty(quotesBaseUrl))
+        {
+            throw new ApplicationException("the QUOTES_BASE_URL environment variable must be defined");
+        }
+        client.BaseAddress = new Uri(quotesBaseUrl);
+    });
 
 // configure telemetry.
 if (Environment.GetEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT") != null)
@@ -32,6 +43,7 @@
             .AddAspNetCoreInstrumentation()
             .AddOtlpExporter())
         .WithTracing(tracing => tracing
+            .AddHttpClientInstrumentation()
             .AddAspNetCoreInstrumentation()
             .AddOtlpExporter()
             .AddConsoleExporter());

quotes/Quotes.csproj

@@ -14,6 +14,7 @@
     <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.9.0" />
     <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.9.0" />
     <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.9.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.9.0" />
     <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.9.0" />
     <PackageReference Include="OpenTelemetry.ResourceDetectors.Container" Version="1.0.0-beta.7" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />