Added custom authentication support to Garnet. (#648)

* Added custom authenticator to support MISE.

* Need to extend GarnetAclAuthenticator while creating custom authenticator. Making it public

* Reverting public for GarnetAclAuthenticator

* Updated param name with Override suffix. Setting AuthSetting during Garnet server intiialization and removed custom auth enum

* Keeping default to throw exception.

* Moved new parameter to last for backward compatibility

* Adding IGarnetAclAuthenticator interface and updated corresponding references

* Revert "Adding IGarnetAclAuthenticator interface and updated corresponding references"

This reverts commit a2322fa.

* Made GarnetAclAuthenticator public

---------

Co-authored-by: Tejas Kulkarni (from Dev Box) <[email protected]>
Co-authored-by: Badrish Chandramouli <[email protected]>

libs/host/GarnetServer.cs

@@ -9,6 +9,7 @@
 using Garnet.common;
 using Garnet.networking;
 using Garnet.server;
+using Garnet.server.Auth.Settings;
 using Microsoft.Extensions.Logging;
 using Tsavorite.core;
 
@@ -76,7 +77,9 @@ public class GarnetServer : IDisposable
         /// </summary>
         /// <param name="commandLineArgs">Command line arguments</param>
         /// <param name="loggerFactory">Logger factory</param>
-        public GarnetServer(string[] commandLineArgs, ILoggerFactory loggerFactory = null, bool cleanupDir = false)
+        /// <param name="cleanupDir">Clean up directory.</param>
+        /// <param name="authenticationSettingsOverride">Override for custom authentication settings.</param>
+        public GarnetServer(string[] commandLineArgs, ILoggerFactory loggerFactory = null, bool cleanupDir = false, IAuthenticationSettings authenticationSettingsOverride = null)
         {
             Trace.Listeners.Add(new ConsoleTraceListener());
 
@@ -125,6 +128,7 @@ public GarnetServer(string[] commandLineArgs, ILoggerFactory loggerFactory = nul
 
             // Assign values to GarnetServerOptions
             this.opts = serverSettings.GetServerOptions(this.loggerFactory.CreateLogger("Options"));
+            this.opts.AuthSettings = authenticationSettingsOverride ?? this.opts.AuthSettings;
             this.cleanupDir = cleanupDir;
             this.InitializeServer();
         }

libs/server/Auth/GarnetACLAuthenticator.cs

@@ -8,7 +8,7 @@
 
 namespace Garnet.server.Auth
 {
-    abstract class GarnetACLAuthenticator : IGarnetAuthenticator
+    public abstract class GarnetACLAuthenticator : IGarnetAuthenticator
     {
         /// <summary>
         /// The Access Control List to authenticate users against