Register the sample's DbContext on the plain Npgsql provider

Directory.Packages.props

@@ -30,7 +30,9 @@
   </ItemGroup>
 
   <ItemGroup Label="Aspire — client integrations (consumed by the API)">
-    <PackageVersion Include="Aspire.Npgsql.EntityFrameworkCore.PostgreSQL" Version="13.5.2" />
+    <PackageVersion Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="10.0.3" />
+    <!-- Backs the AddDbContextCheck<AppDbContext>() readiness probe in samples/SampleApp. -->
+    <PackageVersion Include="Microsoft.Extensions.Diagnostics.HealthChecks.EntityFrameworkCore" Version="10.0.11" />
     <PackageVersion Include="Aspire.StackExchange.Redis" Version="13.5.2" />
     <!-- Referenced only when the matching provider block in Program.cs is uncommented. -->
     <PackageVersion Include="Aspire.Npgsql" Version="13.5.2" />
@@ -78,9 +80,7 @@
     <PackageVersion Include="Testcontainers.PostgreSql" Version="4.14.0" />
     <PackageVersion Include="Testcontainers.MongoDb" Version="4.14.0" />
     <PackageVersion Include="Testcontainers.MsSql" Version="4.14.0" />
-    <PackageVersion Include="Microsoft.Data.SqlClient" Version="6.1.4" />
-    <PackageVersion Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="10.0.3" />
-    <PackageVersion Include="Npgsql" Version="10.0.3" />
+    <PackageVersion Include="Microsoft.Data.SqlClient" Version="6.1.6" />
   </ItemGroup>
 
   <ItemGroup Label="Testing">

aspire/DotNetBoost.Settings.AppHost/AppHost.cs

@@ -85,6 +85,11 @@
     .WithReference(redis)
     .WaitFor(redis)
     .WithEnvironment("Settings__EncryptionKey", encryptionKey)
+    // /health carries the AddDbContextCheck registered in samples/SampleApp/Program.cs, so
+    // this is what makes the dashboard's WaitFor(api) below hold until Postgres actually
+    // answers rather than merely until the process is up. MapDefaultEndpoints only maps
+    // /health in Development — drop this line if you ever publish this AppHost.
+    .WithHttpHealthCheck("/health")
     .WithExternalHttpEndpoints();
 
 // ── Dashboard — clients/dashboard (Nuxt) ─────────────────────────────────────

samples/SampleApp/Program.cs

@@ -1,5 +1,8 @@
 using DotNetBoost.Settings.Core.Interfaces;
 using Microsoft.EntityFrameworkCore;
+using OpenTelemetry;
+using OpenTelemetry.Metrics;
+using OpenTelemetry.Trace;
 using SampleApp;
 using SampleApp.Caching;
 using SampleApp.Settings;
@@ -23,7 +26,34 @@
 //  block, uncomment the one you want, flip the matching ItemGroup in SampleApp.csproj,
 //  the provider block in AppHost.cs, and the DatabaseProvider in AppDbContext.cs.
 // ─────────────────────────────────────────────────────────────────────────────
-builder.AddNpgsqlDbContext<AppDbContext>("settingsdb");
+builder.Services.AddDbContext<AppDbContext>(opt =>
+    opt.UseNpgsql(
+        builder.Configuration.GetConnectionString("settingsdb"),
+        // A cold Postgres container refuses a few connections before it accepts any, so
+        // retry transient failures instead of failing the first request after a restart.
+        // Bounded deliberately: the readiness probe below runs through this same strategy,
+        // and the default policy (6 retries backing off to 30s) makes it take about a
+        // minute to report a database that is plainly gone.
+        npgsql => npgsql.EnableRetryOnFailure(
+            maxRetryCount: 3,
+            maxRetryDelay: TimeSpan.FromSeconds(2),
+            errorCodesToAdd: null)));
+
+// The two registrations below come free with Aspire.Npgsql.EntityFrameworkCore.PostgreSQL
+// and have to be written out when the plain provider is used, as it is here:
+//   readiness — without it /health answers Healthy while Postgres is unreachable, which
+//               makes it useless to anything that gates traffic on it. Nothing polls it
+//               today: add .WithHttpHealthCheck("/health") to the api resource in
+//               AppHost.cs to make WaitFor(api) wait on the database too.
+//   telemetry — Npgsql's ActivitySource and Meter, so a trace on the dashboard shows the
+//               SQL a request ran instead of stopping at the HTTP span, and the Metrics
+//               page carries the connection-pool counters.
+builder.Services.AddHealthChecks()
+    .AddDbContextCheck<AppDbContext>();
+
+builder.Services.AddOpenTelemetry()
+    .WithTracing(tracing => tracing.AddSource("Npgsql"))
+    .WithMetrics(metrics => metrics.AddMeter("Npgsql"));
 
 // ─────────────────────────────────────────────────────────────────────────────
 //  Storage provider — ALTERNATIVE: SQL Server (Entity Framework Core)

samples/SampleApp/SampleApp.csproj

@@ -22,7 +22,8 @@
     in Program.cs and the container started by aspire/DotNetBoost.Settings.AppHost.
   -->
   <ItemGroup Label="Storage provider — ACTIVE: PostgreSQL (EF Core)">
-    <PackageReference Include="Aspire.Npgsql.EntityFrameworkCore.PostgreSQL" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" />
+    <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks.EntityFrameworkCore" />
   </ItemGroup>
 
   <ItemGroup Label="Storage provider — ALTERNATIVE: MongoDB">

tests/DotNetBoost.Settings.IntegrationTests/DotNetBoost.Settings.IntegrationTests.csproj

@@ -20,6 +20,5 @@
     <PackageReference Include="Microsoft.Data.SqlClient" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" />
-    <PackageReference Include="Npgsql" />
   </ItemGroup>
 </Project>