Add logging to TenantResolver for tenant resolution

framework/src/Volo.Abp.MultiTenancy/Volo/Abp/MultiTenancy/TenantResolver.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using Volo.Abp.DependencyInjection;
 
@@ -8,25 +10,31 @@ namespace Volo.Abp.MultiTenancy;
 
 public class TenantResolver : ITenantResolver, ITransientDependency
 {
-    private readonly IServiceProvider _serviceProvider;
-    private readonly AbpTenantResolveOptions _options;
+    public ILogger<TenantResolver> Logger { get; set; }
+
+    protected IServiceProvider ServiceProvider { get; }
+    protected AbpTenantResolveOptions Options { get; }
 
     public TenantResolver(IOptions<AbpTenantResolveOptions> options, IServiceProvider serviceProvider)
     {
-        _serviceProvider = serviceProvider;
-        _options = options.Value;
+        Logger = NullLogger<TenantResolver>.Instance;
+
+        ServiceProvider = serviceProvider;
+        Options = options.Value;
     }
 
     public virtual async Task<TenantResolveResult> ResolveTenantIdOrNameAsync()
     {
         var result = new TenantResolveResult();
 
-        using (var serviceScope = _serviceProvider.CreateScope())
+        Logger.LogDebug("Starting resolving tenant...");
+        using (var serviceScope = ServiceProvider.CreateScope())
         {
             var context = new TenantResolveContext(serviceScope.ServiceProvider);
 
-            foreach (var tenantResolver in _options.TenantResolvers)
+            foreach (var tenantResolver in Options.TenantResolvers)
             {
+                Logger.LogDebug($"Trying to resolve tenant through '{tenantResolver.Name}'...");
                 await tenantResolver.ResolveAsync(context);
 
                 result.AppliedResolvers.Add(tenantResolver.Name);
@@ -34,15 +42,21 @@ public class TenantResolver : ITenantResolver, ITransientDependency
                 if (context.HasResolvedTenantOrHost())
                 {
                     result.TenantIdOrName = context.TenantIdOrName;
+                    Logger.LogDebug($"Tenant resolved by '{tenantResolver.Name}' as '{result.TenantIdOrName ?? "Host"}'.");
                     break;
                 }
             }
         }
 
-        if (result.TenantIdOrName.IsNullOrEmpty() && !string.IsNullOrWhiteSpace(_options.FallbackTenant))
+        if (result.TenantIdOrName.IsNullOrEmpty() && !string.IsNullOrWhiteSpace(Options.FallbackTenant))
         {
-            result.TenantIdOrName = _options.FallbackTenant;
+            result.TenantIdOrName = Options.FallbackTenant;
             result.AppliedResolvers.Add(TenantResolverNames.FallbackTenant);
+            Logger.LogDebug($"No tenant resolved. Using fallback tenant as '{result.TenantIdOrName}'.");
+        }
+        else if (result.TenantIdOrName.IsNullOrEmpty())
+        {
+            Logger.LogDebug("No tenant resolved.");
         }
 
         return result;