U4-9018 - provide a way to disable server master election

src/Umbraco.Core/Sync/SingleServerRegistrar.cs

@@ -0,0 +1,37 @@
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Sync
+{
+    public class SingleServerRegistrar : IServerRegistrar2
+    {
+        private readonly string _umbracoApplicationUrl;
+
+        public IEnumerable<IServerAddress> Registrations { get; private set; }
+
+        public SingleServerRegistrar()
+        {
+            _umbracoApplicationUrl = ApplicationContext.Current.UmbracoApplicationUrl;
+            Registrations = new[] { new ServerAddressImpl(_umbracoApplicationUrl) };
+        }
+
+        public ServerRole GetCurrentServerRole()
+        {
+            return ServerRole.Single;
+        }
+
+        public string GetCurrentServerUmbracoApplicationUrl()
+        {
+            return _umbracoApplicationUrl;
+        }
+
+        private class ServerAddressImpl : IServerAddress
+        {
+            public ServerAddressImpl(string serverAddress)
+            {
+                ServerAddress = serverAddress;
+            }
+
+            public string ServerAddress { get; private set; }
+        }
+    }
+}

src/Umbraco.Core/Umbraco.Core.csproj

@@ -1330,6 +1330,7 @@
     <Compile Include="Sync\ApplicationUrlHelper.cs" />
     <Compile Include="Sync\RefreshMethodType.cs" />
     <Compile Include="Sync\ServerMessengerBase.cs" />
+    <Compile Include="Sync\SingleServerRegistrar.cs" />
     <Compile Include="ThreadExtensions.cs" />
     <Compile Include="TopologicalSorter.cs" />
     <Compile Include="Strings\DefaultUrlSegmentProvider.cs" />