public static IServiceCollection ConfigureFunctionsApplicationInsights()

in src/DotNetWorker.ApplicationInsights/FunctionsApplicationInsightsExtensions.cs [22:66]
33 lines of code
3 McCabe index (conditional complexity)

        public static IServiceCollection ConfigureFunctionsApplicationInsights(this IServiceCollection services)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            services.ConfigureOptions<TelemetryConfigurationSetup>();
            services.AddSingleton<IConfigureOptions<AppServiceOptions>, AppServiceOptionsInitializer>();
            services.AddSingleton<AppServiceEnvironmentVariableMonitor>();
            services.AddSingleton<IOptionsChangeTokenSource<AppServiceOptions>>(p => p.GetRequiredService<AppServiceEnvironmentVariableMonitor>());
            services.AddSingleton<IHostedService>(p => p.GetRequiredService<AppServiceEnvironmentVariableMonitor>());

            services.AddSingleton<FunctionsRoleInstanceProvider>();

            services.TryAddEnumerable(ServiceDescriptor.Singleton<ITelemetryInitializer, FunctionsTelemetryInitializer>());
            services.AddSingleton<ITelemetryInitializer>(provider =>
            {
                // To match parity with the Host, we need to update the QuickPulseTelemetryModule.ServerId. We don't want to reference the
                // top-level WorkerService or AspNetCore packages, so we cannot use ConfigureTelemetryModules().
                // 
                // Nesting this setup inside this ITelemetryInitializer factory as it guarantees it will be run before
                // any ITelemetryModules are initialized.
                var modules = provider.GetServices<ITelemetryModule>();
                var quickPulseModule = modules.OfType<QuickPulseTelemetryModule>().SingleOrDefault();
                if (quickPulseModule is not null)
                {
                    var roleInstanceProvider = provider.GetRequiredService<FunctionsRoleInstanceProvider>();
                    quickPulseModule.ServerId = roleInstanceProvider.GetRoleInstanceName();
                }

                return ActivatorUtilities.CreateInstance<FunctionsRoleEnvironmentTelemetryInitializer>(provider);
            });
            services.TryAddEnumerable(ServiceDescriptor.Singleton<ITelemetryModule, FunctionsTelemetryModule>());
            services.AddOptions<FunctionsApplicationInsightsOptions>()
                .Validate<IServiceProvider>(
                    (_, sp) => sp.GetService<TelemetryClient>() is not null,
                    "Application Insights SDK has not been added. Please add and configure the Application Insights SDK. See https://learn.microsoft.com/en-us/azure/azure-monitor/app/worker-service for more information.");

            services.AddHostedService<ApplicationInsightsValidationService>();

            // Lets the host know that the worker is sending logs to App Insights. The host will now ignore these.
            services.Configure<WorkerOptions>(workerOptions => workerOptions.Capabilities["WorkerApplicationInsightsLoggingEnabled"] = bool.TrueString);
            return services;
        }