Add HealthController and configure Dockerfile for health check

Controllers/HealthController.cs

@@ -0,0 +1,16 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace tour_of_heroes_api.Controllers{
+
+    [Route("api/[controller]")]
+    [ApiController]
+    public class HealthController : ControllerBase
+    {
+        // GET: api/Health
+        [HttpGet]
+        public IActionResult Get()
+        {
+            return Ok("Healthy");
+        }
+    }
+}

Dockerfile

@@ -3,6 +3,7 @@ WORKDIR /app
 EXPOSE 5000
 
 ENV ASPNETCORE_URLS=http://+:5000
+ENV OTEL_SERVICE_NAME=tour-of-heroes-api
 
 # Creates a non-root user with an explicit UID and adds permission to access the /app folder
 # For more info, please refer to https://aka.ms/vscode-docker-dotnet-configure-containers
@@ -36,4 +37,13 @@ RUN dotnet publish "tour-of-heroes-api.csproj" -c Release -o /app/publish -r $(c
 FROM base AS final
 WORKDIR /app
 COPY --from=publish /app/publish .
+
+# Install curl
+USER root
+RUN apt-get update && apt-get install -y curl
+USER appuser
+
+HEALTHCHECK --interval=5m --timeout=3s \
+  CMD curl -f http://localhost:5000/api/health || exit 1
+
 ENTRYPOINT ["dotnet", "tour-of-heroes-api.dll"]