Always access config file via provider to utilize lock

src/NzbDrone.Core/Authentication/UserService.cs

@@ -1,7 +1,11 @@
 using System;
+using System.Linq;
 using NzbDrone.Common.Disk;
 using NzbDrone.Common.EnvironmentInfo;
 using NzbDrone.Common.Extensions;
+using NzbDrone.Core.Configuration;
+using NzbDrone.Core.Lifecycle;
+using NzbDrone.Core.Messaging.Events;
 
 namespace NzbDrone.Core.Authentication
 {
@@ -15,17 +19,22 @@ namespace NzbDrone.Core.Authentication
         User FindUser(Guid identifier);
     }
 
-    public class UserService : IUserService
+    public class UserService : IUserService, IHandle<ApplicationStartedEvent>
     {
         private readonly IUserRepository _repo;
         private readonly IAppFolderInfo _appFolderInfo;
         private readonly IDiskProvider _diskProvider;
+        private readonly IConfigFileProvider _configFileProvider;
 
-        public UserService(IUserRepository repo, IAppFolderInfo appFolderInfo, IDiskProvider diskProvider)
+        public UserService(IUserRepository repo,
+            IAppFolderInfo appFolderInfo,
+            IDiskProvider diskProvider,
+            IConfigFileProvider configFileProvider)
         {
             _repo = repo;
             _appFolderInfo = appFolderInfo;
             _diskProvider = diskProvider;
+            _configFileProvider = configFileProvider;
         }
 
         public User Add(string username, string password)
@@ -93,5 +102,28 @@ namespace NzbDrone.Core.Authentication
         {
             return _repo.FindUser(identifier);
         }
+
+        public void Handle(ApplicationStartedEvent message)
+        {
+            if (_repo.All().Any())
+            {
+                return;
+            }
+
+            var xDoc = _configFileProvider.LoadConfigFile();
+            var config = xDoc.Descendants("Config").Single();
+            var usernameElement = config.Descendants("Username").FirstOrDefault();
+            var passwordElement = config.Descendants("Password").FirstOrDefault();
+
+            if (usernameElement == null || passwordElement == null)
+            {
+                return;
+            }
+
+            var username = usernameElement.Value;
+            var password = passwordElement.Value;
+
+            Add(username, password);
+        }
     }
 }

src/NzbDrone.Core/Configuration/ConfigFileProvider.cs

@@ -22,6 +22,7 @@ namespace NzbDrone.Core.Configuration
     public interface IConfigFileProvider : IHandleAsync<ApplicationStartedEvent>,
                                            IExecute<ResetApiKeyCommand>
     {
+        XDocument LoadConfigFile();
         Dictionary<string, object> GetConfigDictionary();
         void SaveConfigDictionary(Dictionary<string, object> configValues);
         void EnsureDefaultConfigFile();
@@ -342,7 +343,7 @@ namespace NzbDrone.Core.Configuration
             SaveConfigFile(xDoc);
         }
 
-        private XDocument LoadConfigFile()
+        public XDocument LoadConfigFile()
         {
             try
             {