Add Configure.Smtp.cs

MyApp/Configure.Smtp.cs

@@ -0,0 +1,31 @@
+using MyApp.ServiceInterface;
+
+[assembly: HostingStartup(typeof(MyApp.ConfigureSmtp))]
+
+namespace MyApp;
+
+public class ConfigureSmtp : IHostingStartup
+{
+    public void Configure(IWebHostBuilder builder) => builder
+        .ConfigureServices((context,services) => {
+            var smtpConfig = context.Configuration.GetSection(nameof(SmtpConfig))?.Get<SmtpConfig>();
+            if (smtpConfig is not null)
+            {
+                services.AddSingleton(smtpConfig);
+            }
+        })
+        .ConfigureAppHost(appHost => {
+            // Check if SMTP is configured
+            var smtpConfig = appHost.TryResolve<SmtpConfig>();
+            var log = appHost.GetApplicationServices().GetRequiredService<ILogger<ConfigureSmtp>>();
+            // Log if missing
+            if (smtpConfig is null)
+            {
+                log.LogWarning("SMTP is not configured, please configure SMTP to enable sending emails");
+            }
+            else
+            {
+                log.LogWarning("SMTP is configured with <{SmtpConfigFromEmail}> {SmtpConfigFromName}", smtpConfig.FromEmail, smtpConfig.FromName);
+            }
+        });
+}