Conditionally configures Application Insights. (#746)

Ensures Application Insights is configured only if a connection string
is available.

Adds logging to warn when the connection string is missing, disabling
telemetry collection.

Author: BenjaminMichaelis

EssentialCSharp.Web/Program.cs

@@ -1,23 +1,23 @@
-using Azure.Monitor.OpenTelemetry.AspNetCore;
-using EssentialCSharp.Web.Areas.Identity.Data;
-using EssentialCSharp.Web.Areas.Identity.Services.PasswordValidators;
-using EssentialCSharp.Web.Data;
-using EssentialCSharp.Web.Extensions;
-using EssentialCSharp.Web.Middleware;
-using EssentialCSharp.Web.Services;
-using EssentialCSharp.Web.Services.Referrals;
+using Azure.Monitor.OpenTelemetry.AspNetCore;
+using EssentialCSharp.Web.Areas.Identity.Data;
+using EssentialCSharp.Web.Areas.Identity.Services.PasswordValidators;
+using EssentialCSharp.Web.Data;
+using EssentialCSharp.Web.Extensions;
+using EssentialCSharp.Web.Middleware;
+using EssentialCSharp.Web.Services;
+using EssentialCSharp.Web.Services.Referrals;
 using Mailjet.Client;
 using Microsoft.AspNetCore.HttpOverrides;
 using Microsoft.AspNetCore.Identity;
-using Microsoft.AspNetCore.Identity.UI.Services;
-using Microsoft.EntityFrameworkCore;
-
-namespace EssentialCSharp.Web;
-
-public partial class Program
-{
-    private static void Main(string[] args)
-    {
+using Microsoft.AspNetCore.Identity.UI.Services;
+using Microsoft.EntityFrameworkCore;
+
+namespace EssentialCSharp.Web;
+
+public partial class Program
+{
+    private static void Main(string[] args)
+    {
         WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
 
         builder.Services.Configure<ForwardedHeadersOptions>(options =>
@@ -31,20 +31,35 @@ private static void Main(string[] args)
             options.KnownNetworks.Clear();
             options.KnownProxies.Clear();
         });
-
-        ConfigurationManager configuration = builder.Configuration;
+
+        ConfigurationManager configuration = builder.Configuration;
         string connectionString = builder.Configuration.GetConnectionString("EssentialCSharpWebContextConnection") ?? throw new InvalidOperationException("Connection string 'EssentialCSharpWebContextConnection' not found.");
 
-        builder.Logging.AddConsole();
-        builder.Services.AddHealthChecks();
+        builder.Logging.AddConsole();
+        builder.Services.AddHealthChecks();
+
+        // Create a temporary logger for startup logging
+        using var loggerFactory = LoggerFactory.Create(loggingBuilder =>
+            loggingBuilder.AddConsole().SetMinimumLevel(LogLevel.Information));
+        var logger = loggerFactory.CreateLogger<Program>();
 
         if (!builder.Environment.IsDevelopment())
         {
-            // Configure Azure Application Insights with OpenTelemetry
-            builder.Services.AddOpenTelemetry().UseAzureMonitor();
-            builder.Services.AddApplicationInsightsTelemetry();
-            builder.Services.AddServiceProfiler();
-        }
+            // Configure Azure Application Insights with OpenTelemetry only if connection string is available
+            var appInsightsConnectionString = builder.Configuration.GetConnectionString("ApplicationInsights")
+                ?? builder.Configuration["ApplicationInsights:ConnectionString"];
+
+            if (!string.IsNullOrEmpty(appInsightsConnectionString))
+            {
+                builder.Services.AddOpenTelemetry().UseAzureMonitor();
+                builder.Services.AddApplicationInsightsTelemetry();
+                builder.Services.AddServiceProfiler();
+            }
+            else
+            {
+                logger.LogWarning("Application Insights connection string not found. Telemetry collection will be disabled.");
+            }
+        }
 
         builder.Services.AddDbContext<EssentialCSharpWebContext>(options => options.UseSqlServer(connectionString));
         builder.Services.AddDefaultIdentity<EssentialCSharpWebUser>(options =>
@@ -70,9 +85,9 @@ private static void Main(string[] args)
             .AddEntityFrameworkStores<EssentialCSharpWebContext>()
              .AddPasswordValidator<UsernameOrEmailAsPasswordValidator<EssentialCSharpWebUser>>()
              .AddPasswordValidator<Top100000PasswordValidator<EssentialCSharpWebUser>>();
-
-        builder.Configuration
-            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
+
+        builder.Configuration
+            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
             .AddEnvironmentVariables();
 
         builder.Services.ConfigureApplicationCookie(options =>
@@ -113,22 +128,22 @@ private static void Main(string[] args)
                 return userPasswordStore;
             }
             throw new NotSupportedException("The default UI requires a user store with password support.");
-        });
+        });
 
-        //TODO: Implement the anti-forgery token with every POST/PUT request: https://learn.microsoft.com/en-us/aspnet/core/security/anti-request-forgery
+        //TODO: Implement the anti-forgery token with every POST/PUT request: https://learn.microsoft.com/en-us/aspnet/core/security/anti-request-forgery
 
         if (!builder.Environment.IsDevelopment())
         {
             builder.Services.AddTransient<IEmailSender, EmailSender>();
         }
         builder.Services.Configure<AuthMessageSenderOptions>(builder.Configuration.GetSection(AuthMessageSenderOptions.AuthMessageSender));
-
-        // Add services to the container.
+
+        // Add services to the container.
         builder.Services.AddRazorPages();
         builder.Services.AddCaptchaService(builder.Configuration.GetSection(CaptchaOptions.CaptchaSender));
         builder.Services.AddSingleton<ISiteMappingService, SiteMappingService>();
         builder.Services.AddHostedService<DatabaseMigrationService>();
-        builder.Services.AddScoped<IReferralService, ReferralService>();
+        builder.Services.AddScoped<IReferralService, ReferralService>();
 
         if (!builder.Environment.IsDevelopment())
         {
@@ -161,11 +176,12 @@ private static void Main(string[] args)
         }
 
 
-
+
         WebApplication app = builder.Build();
-        // Configure the HTTP request pipeline.
-        if (!app.Environment.IsDevelopment())
-        {
+
+        // Configure the HTTP request pipeline.
+        if (!app.Environment.IsDevelopment())
+        {
             app.UseExceptionHandler("/Error");
             app.UseForwardedHeaders();
             app.UseHsts();
@@ -176,25 +192,25 @@ private static void Main(string[] args)
         {
             app.UseDeveloperExceptionPage();
             app.UseForwardedHeaders();
-        }
+        }
 
         app.MapHealthChecks("/healthz");
-
-        app.UseHttpsRedirection();
-        app.UseStaticFiles();
-
+
+        app.UseHttpsRedirection();
+        app.UseStaticFiles();
+
         app.UseRouting();
 
-        app.UseAuthentication();
+        app.UseAuthentication();
         app.UseAuthorization();
         app.UseMiddleware<ReferralMiddleware>();
-
-
-        app.MapRazorPages();
+
+
+        app.MapRazorPages();
         app.MapDefaultControllerRoute();
 
-        app.MapFallbackToController("Index", "Home");
-
-        app.Run();
+        app.MapFallbackToController("Index", "Home");
+
+        app.Run();
     }
-}
+}