Refactor RuntimeConfig into Interface with Local and Hosted Providers

src/Cli/ConfigGenerator.cs

@@ -1104,7 +1104,7 @@ public static bool IsConfigValid(ValidateOptions options, FileSystemRuntimeConfi
                 _logger.LogInformation("Loaded config file: {runtimeConfigFile}", runtimeConfigFile);
             }
 
-            RuntimeConfigProvider runtimeConfigProvider = new(loader);
+            LocalRuntimeConfigProvider runtimeConfigProvider = new(loader);
 
             ILogger<RuntimeConfigValidator> runtimeConfigValidatorLogger = LoggerFactoryForCli.CreateLogger<RuntimeConfigValidator>();
             RuntimeConfigValidator runtimeConfigValidator = new(runtimeConfigProvider, fileSystem, runtimeConfigValidatorLogger, true);

src/Core/Configurations/ConfigFileWatcher.cs → src/Config/ConfigFileWatcher.cs

@@ -1,22 +1,22 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-namespace Azure.DataApiBuilder.Core.Configurations;
+namespace Azure.DataApiBuilder.Config;
 
 public class ConfigFileWatcher
 {
     private FileSystemWatcher? _fileWatcher;
-    private readonly RuntimeConfigProvider? _configProvider;
+    private FileSystemRuntimeConfigLoader _configLoader;
 
-    public ConfigFileWatcher(RuntimeConfigProvider configProvider, string directoryName, string configFileName)
+    public ConfigFileWatcher(FileSystemRuntimeConfigLoader configLoader, string directoryName, string configFileName)
     {
         _fileWatcher = new FileSystemWatcher(directoryName)
         {
             Filter = configFileName,
             EnableRaisingEvents = true
         };
 
-        _configProvider = configProvider;
+        _configLoader = configLoader;
         _fileWatcher.Changed += OnConfigFileChange;
     }
 
@@ -31,14 +31,19 @@ private void OnConfigFileChange(object sender, FileSystemEventArgs e)
     {
         try
         {
-            if (_configProvider is null)
+            if (_configLoader is null)
             {
                 throw new ArgumentNullException("_configProvider can not be null.");
             }
 
-            if (!_configProvider.IsLateConfigured && _configProvider.GetConfig().IsDevelopmentMode())
+            if (_configLoader.RuntimeConfig is null)
             {
-                _configProvider.HotReloadConfig();
+                throw new ArgumentNullException("RuntimeConfig can not be null.");
+            }
+
+            if (_configLoader.RuntimeConfig.IsDevelopmentMode())
+            {
+                _configLoader.HotReloadConfig();
             }
         }
         catch (Exception ex)

src/Config/FileSystemRuntimeConfigLoader.cs

@@ -29,6 +29,8 @@ public class FileSystemRuntimeConfigLoader : RuntimeConfigLoader
     // or user provided config file which could be a relative file path, absolute file path or simply the file name assumed to be in current directory.
     private string _baseConfigFilePath;
 
+    private ConfigFileWatcher? _configFileWatcher;
+
     private readonly IFileSystem _fileSystem;
 
     public const string CONFIGFILE_NAME = "dab-config";
@@ -87,6 +89,32 @@ public string GetConfigFileName()
         return configFileName;
     }
 
+    /// <summary>
+    /// Checks if we have already attempted to configure the file watcher, if not
+    /// instantiate the file watcher if we are in the correct mode.
+    /// Returns true if we instantiate a file watcher.
+    /// </summary>
+    private bool TrySetupConfigFileWatcher()
+    {
+        if (RuntimeConfig is not null && RuntimeConfig.IsDevelopmentMode())
+        {
+            try
+            {
+                _configFileWatcher = new(this, GetConfigDirectoryName(), GetConfigFileName());
+            }
+            catch (Exception ex)
+            {
+                // Need to remove the dependencies in startup on the RuntimeConfigProvider
+                // before we can have an ILogger here.
+                Console.WriteLine($"Attempt to configure config file watcher for hot reload failed due to: {ex.Message}.");
+            }
+
+            return _configFileWatcher is not null;
+        }
+
+        return false;
+    }
+
     /// <summary>
     /// Load the runtime config from the specified path.
     /// </summary>
@@ -104,7 +132,10 @@ public string GetConfigFileName()
         {
             Console.WriteLine($"Loading config file from {path}.");
             string json = _fileSystem.File.ReadAllText(path);
-            return TryParseConfig(json, out config, connectionString: _connectionString, replaceEnvVar: replaceEnvVar);
+            bool res = TryParseConfig(json, out RuntimeConfig, connectionString: _connectionString, replaceEnvVar: replaceEnvVar);
+            TrySetupConfigFileWatcher();
+            config = RuntimeConfig;
+            return res;
         }
         else
         {
@@ -129,6 +160,15 @@ public override bool TryLoadKnownConfig([NotNullWhen(true)] out RuntimeConfig? c
         return TryLoadConfig(ConfigFilePath, out config, replaceEnvVar);
     }
 
+    /// <summary>
+    /// Hot Reloads the runtime config when the file watcher
+    /// is active and detects a change to the underlying config file.
+    /// </summary>
+    public void HotReloadConfig()
+    {
+        TryLoadKnownConfig(out _, replaceEnvVar: true);
+    }
+
     /// <summary>
     /// Precedence of environments is
     /// 1) Value of DAB_ENVIRONMENT.

src/Config/ObjectModel/RuntimeConfig.cs

@@ -169,7 +169,7 @@ public RuntimeConfig(string? Schema, DataSource DataSource, RuntimeEntities Enti
         this.DataSource = DataSource;
         this.Runtime = Runtime;
         this.Entities = Entities;
-        _defaultDataSourceName = Guid.NewGuid().ToString();
+        _defaultDataSourceName = DataSource.ConnectionString.GetHashCode().ToString();
 
         // we will set them up with default values
         _dataSourceNameToDataSource = new Dictionary<string, DataSource>

src/Config/RuntimeConfigLoader.cs

@@ -22,6 +22,8 @@ public abstract class RuntimeConfigLoader
 {
     protected readonly string? _connectionString;
 
+    public RuntimeConfig? RuntimeConfig;
+
     public RuntimeConfigLoader(string? connectionString = null)
     {
         _connectionString = connectionString;

src/Core/AuthenticationHelpers/AuthenticationSimulator/SimulatorAuthenticationHandler.cs

@@ -32,7 +32,7 @@ public class SimulatorAuthenticationHandler : AuthenticationHandler<Authenticati
     /// <param name="encoder">URL encoder.</param>
     /// <param name="clock">System clock.</param>
     public SimulatorAuthenticationHandler(
-        RuntimeConfigProvider runtimeConfigProvider,
+        IRuntimeConfigProvider runtimeConfigProvider,
         IOptionsMonitor<AuthenticationSchemeOptions> options,
         ILoggerFactory logger,
         UrlEncoder encoder,

src/Core/AuthenticationHelpers/ClientRoleHeaderAuthenticationMiddleware.cs

@@ -34,7 +34,7 @@ public class ClientRoleHeaderAuthenticationMiddleware
 
     public ClientRoleHeaderAuthenticationMiddleware(RequestDelegate next,
         ILogger<ClientRoleHeaderAuthenticationMiddleware> logger,
-        RuntimeConfigProvider runtimeConfigProvider)
+        IRuntimeConfigProvider runtimeConfigProvider)
     {
         _nextMiddleware = next;
         _logger = logger;

src/Core/Authorization/AuthorizationResolver.cs

@@ -23,7 +23,7 @@ namespace Azure.DataApiBuilder.Core.Authorization;
 /// </summary>
 public class AuthorizationResolver : IAuthorizationResolver
 {
-    private readonly RuntimeConfigProvider _runtimeConfigProvider;
+    private readonly IRuntimeConfigProvider _runtimeConfigProvider;
     private readonly IMetadataProviderFactory _metadataProviderFactory;
     public const string WILDCARD = "*";
     public const string CLAIM_PREFIX = "@claims.";
@@ -36,7 +36,7 @@ public class AuthorizationResolver : IAuthorizationResolver
     public Dictionary<string, EntityMetadata> EntityPermissionsMap { get; private set; } = new();
 
     public AuthorizationResolver(
-        RuntimeConfigProvider runtimeConfigProvider,
+        IRuntimeConfigProvider runtimeConfigProvider,
         IMetadataProviderFactory metadataProviderFactory
         )
     {
@@ -48,7 +48,7 @@ IMetadataProviderFactory metadataProviderFactory
         }
         else
         {
-            runtimeConfigProvider.RuntimeConfigLoadedHandlers.Add((RuntimeConfigProvider sender, RuntimeConfig config) =>
+            runtimeConfigProvider.RuntimeConfigLoadedHandlers.Add((IRuntimeConfigProvider sender, RuntimeConfig config) =>
             {
                 SetEntityPermissionMap(config);
                 return Task.FromResult(true);

src/Core/Configurations/RuntimeConfigProvider.cs → src/Core/Configurations/HostedRuntimeConfigProvider.cs

@@ -10,45 +10,34 @@
 using Azure.DataApiBuilder.Config.NamingPolicies;
 using Azure.DataApiBuilder.Config.ObjectModel;
 using Azure.DataApiBuilder.Service.Exceptions;
+using static Azure.DataApiBuilder.Core.Configurations.IRuntimeConfigProvider;
 
 namespace Azure.DataApiBuilder.Core.Configurations;
 
 /// <summary>
-/// This class is responsible for exposing the runtime config to the rest of the service.
-/// The <c>RuntimeConfigProvider</c> won't directly load the config, but will instead rely on the <see cref="FileSystemRuntimeConfigLoader"/> to do so.
+/// This class is responsible for exposing the runtime config to the rest of the service when in a hosted scenario.
+/// The <c>HostedRuntimeConfigProvider</c> won't directly load the config, but will instead rely on the <see cref="FileSystemRuntimeConfigLoader"/> to do so.
 /// </summary>
 /// <remarks>
-/// The <c>RuntimeConfigProvider</c> will maintain internal state of the config, and will only load it once.
+/// The <c>HostedRuntimeConfigProvider</c> will maintain internal state of the config, and will only load it once.
 ///
 /// This class should be treated as the owner of the config that is available within the service, and other classes
 /// should not load the config directly, or maintain a reference to it, so that we can do hot-reloading by replacing
 /// the config that is available from this type.
 /// </remarks>
-public class RuntimeConfigProvider
+public class HostedRuntimeConfigProvider : IRuntimeConfigProvider
 {
-    public delegate Task<bool> RuntimeConfigLoadedHandler(RuntimeConfigProvider sender, RuntimeConfig config);
-
     public List<RuntimeConfigLoadedHandler> RuntimeConfigLoadedHandlers { get; } = new List<RuntimeConfigLoadedHandler>();
 
-    /// <summary>
-    /// Indicates whether the config was loaded after the runtime was initialized.
-    /// </summary>
-    /// <remarks>This is most commonly used when DAB's config is provided via the <c>ConfigurationController</c>, such as when it's a hosted service.</remarks>
     public bool IsLateConfigured { get; set; }
 
-    /// <summary>
-    /// The access tokens representing a Managed Identity to connect to the database.
-    /// The key is the unique datasource name and the value is the access token.
-    /// </summary>
-    public Dictionary<string, string?> ManagedIdentityAccessToken { get; private set; } = new Dictionary<string, string?>();
-
-    public RuntimeConfigLoader ConfigLoader { get; private set; }
+    public Dictionary<string, string?> ManagedIdentityAccessToken { get; set; } = new Dictionary<string, string?>();
 
-    private ConfigFileWatcher? _configFileWatcher;
+    public RuntimeConfigLoader ConfigLoader { get; set; }
 
-    private RuntimeConfig? _runtimeConfig;
+    public RuntimeConfig? _runtimeConfig;
 
-    public RuntimeConfigProvider(RuntimeConfigLoader runtimeConfigLoader)
+    public HostedRuntimeConfigProvider(RuntimeConfigLoader runtimeConfigLoader)
     {
         ConfigLoader = runtimeConfigLoader;
     }
@@ -66,93 +55,23 @@ public RuntimeConfig GetConfig()
         {
             return _runtimeConfig;
         }
-
-        // While loading the config file, replace all the environment variables with their values.
-        if (ConfigLoader.TryLoadKnownConfig(out RuntimeConfig? config, replaceEnvVar: true))
-        {
-            _runtimeConfig = config;
-            TrySetupConfigFileWatcher();
-        }
-
-        if (_runtimeConfig is null)
+        else
         {
             throw new DataApiBuilderException(
                 message: "Runtime config isn't setup.",
                 statusCode: HttpStatusCode.ServiceUnavailable,
                 subStatusCode: DataApiBuilderException.SubStatusCodes.ErrorInInitialization);
         }
-
-        return _runtimeConfig;
-    }
-
-    /// <summary>
-    /// Checks if we have already attempted to configure the file watcher, if not
-    /// instantiate the file watcher if we are in the correct scenario. If we
-    /// are not in the correct scenario, do not setup a file watcher but remember
-    /// that we have attempted to do so to avoid repeat checks in future calls.
-    /// Returns true if we instantiate a file watcher.
-    /// </summary>
-    private bool TrySetupConfigFileWatcher()
-    {
-        if (!IsLateConfigured && _runtimeConfig is not null && _runtimeConfig.IsDevelopmentMode())
-        {
-            try
-            {
-                FileSystemRuntimeConfigLoader loader = (FileSystemRuntimeConfigLoader)ConfigLoader;
-                _configFileWatcher = new(this, loader.GetConfigDirectoryName(), loader.GetConfigFileName());
-            }
-            catch (Exception ex)
-            {
-                // Need to remove the dependencies in startup on the RuntimeConfigProvider
-                // before we can have an ILogger here.
-                Console.WriteLine($"Attempt to configure config file watcher for hot reload failed due to: {ex.Message}.");
-            }
-
-            return _configFileWatcher is not null;
-        }
-
-        return false;
     }
 
-    /// <summary>
-    /// Attempt to acquire runtime configuration metadata.
-    /// </summary>
-    /// <param name="runtimeConfig">Populated runtime configuration, if present.</param>
-    /// <returns>True when runtime config is provided, otherwise false.</returns>
     public bool TryGetConfig([NotNullWhen(true)] out RuntimeConfig? runtimeConfig)
     {
-        if (_runtimeConfig is null)
-        {
-            if (ConfigLoader.TryLoadKnownConfig(out RuntimeConfig? config, replaceEnvVar: true))
-            {
-                _runtimeConfig = config;
-                TrySetupConfigFileWatcher();
-            }
-        }
-
-        runtimeConfig = _runtimeConfig;
-        return _runtimeConfig is not null;
+        throw new NotImplementedException();
     }
 
-    /// <summary>
-    /// Attempt to acquire runtime configuration metadata from a previously loaded one.
-    /// This method will not load the config if it hasn't been loaded yet.
-    /// </summary>
-    /// <param name="runtimeConfig">Populated runtime configuration, if present.</param>
-    /// <returns>True when runtime config is provided, otherwise false.</returns>
     public bool TryGetLoadedConfig([NotNullWhen(true)] out RuntimeConfig? runtimeConfig)
     {
-        runtimeConfig = _runtimeConfig;
-        return _runtimeConfig is not null;
-    }
-
-    /// <summary>
-    /// Hot Reloads the runtime config when the file watcher
-    /// is active and detects a change to the underlying config file.
-    /// </summary>
-    public void HotReloadConfig()
-    {
-        ConfigLoader.TryLoadKnownConfig(out _runtimeConfig, replaceEnvVar: true);
+        throw new NotImplementedException();
     }
 
     /// <summary>
@@ -278,7 +197,7 @@ public void HotReloadConfig()
         return false;
     }
 
-    private async Task<bool> InvokeConfigLoadedHandlersAsync()
+    public async Task<bool> InvokeConfigLoadedHandlersAsync()
     {
         List<Task<bool>> configLoadedTasks = new();
         if (_runtimeConfig is not null)