Use username & password (from env vars) for Mongo (#336)

Mongo connections can now use a username and password, specified by
environment variables. If the environment variables are not present or
are empty, then no authentication parameters are sent to Mongo.

src/LfMerge.Core/LanguageDepotProject.cs

@@ -24,7 +24,7 @@ public LanguageDepotProject(LfMergeSettings settings, ILogger logger)
 		public void Initialize(string lfProjectCode)
 		{
 			// TODO: This should use the MongoConnection class instead
-			MongoClient client = new MongoClient("mongodb://" + Settings.MongoDbHostNameAndPort);
+			MongoClient client = new MongoClient("mongodb://" + Settings.MongoDbHostPortAndAuth);
 			IMongoDatabase database = client.GetDatabase("scriptureforge");
 			IMongoCollection<BsonDocument> projectCollection = database.GetCollection<BsonDocument>("projects");
 			//var userCollection = database.GetCollection<BsonDocument>("users");

src/LfMerge.Core/MagicStrings.cs

@@ -20,6 +20,9 @@ static MagicStrings()
 		public const string SettingsEnvVar_TemplatesDir = "LFMERGE_TEMPLATES_DIR";
 		public const string SettingsEnvVar_MongoHostname = "LFMERGE_MONGO_HOSTNAME";
 		public const string SettingsEnvVar_MongoPort = "LFMERGE_MONGO_PORT";
+		public const string SettingsEnvVar_MongoAuthSource = "LFMERGE_MONGO_AUTHSOURCE";
+		public const string SettingsEnvVar_MongoUsername = "LFMERGE_MONGO_USER";
+		public const string SettingsEnvVar_MongoPassword = "LFMERGE_MONGO_PASS";
 		public const string SettingsEnvVar_MongoMainDatabaseName = "LFMERGE_MONGO_MAIN_DB_NAME";
 		public const string SettingsEnvVar_MongoDatabaseNamePrefix = "LFMERGE_MONGO_DB_NAME_PREFIX";
 		public const string SettingsEnvVar_VerboseProgress = "LFMERGE_VERBOSE_PROGRESS";

src/LfMerge.Core/MongoConnector/MongoConnection.cs

@@ -27,6 +27,7 @@ public enum MongoDbSelector {
 
 	public class MongoConnection : IMongoConnection
 	{
+		private string connectionString;
 		private string mainDatabaseName;
 		private Lazy<IMongoClient> client;
 		// Since calling GetDatabase() too often creates a new connection, we memoize the databases in this dictionary.
@@ -72,14 +73,18 @@ public MongoConnection(LfMergeSettings settings, ILogger logger)
 		{
 			_settings = settings;
 			_logger = logger;
+			connectionString = string.Format(
+				"mongodb://{0}?authSource={1}",
+				Settings.MongoDbHostPortAndAuth,
+				Settings.MongoAuthSource);
 			mainDatabaseName = Settings.MongoMainDatabaseName;
 			client = new Lazy<IMongoClient>(GetNewConnection);
 			dbs = new ConcurrentDictionary<string, IMongoDatabase>();
 		}
 
 		private MongoClient GetNewConnection()
 		{
-			var clientSettings = new MongoClientSettings();
+			var clientSettings = MongoClientSettings.FromConnectionString(connectionString);
 			// clientSettings.WriteConcern = WriteConcern.WMajority; // If increasing the wait queue size still doesn't help, try this as well
 			clientSettings.WaitQueueSize = 50000;
 			clientSettings.Server = new MongoServerAddress(Settings.MongoHostname, Settings.MongoPort);

src/LfMerge.Core/Settings/DefaultLfMergeSettings.cs

@@ -12,6 +12,10 @@ public static class DefaultLfMergeSettings
 		public const int MongoPort = 27017;
 		public const string MongoMainDatabaseName = "scriptureforge";
 		public const string MongoDatabaseNamePrefix = "sf_";
+		public const string MongoAuthSource = "admin";
+		// Mongo username and password defaults should be *empty*
+		public const string MongoUsername = "";
+		public const string MongoPassword = "";
 		public const bool VerboseProgress = false;
 		public const string LanguageDepotRepoUri = "";  // optional, usually not set
 	}

src/LfMerge.Core/Settings/LfMergeSettings.cs

@@ -44,6 +44,12 @@ public int MongoPort {
 			}
 		}
 
+		public string MongoAuthSource => Environment.GetEnvironmentVariable(MagicStrings.SettingsEnvVar_MongoAuthSource) ?? DefaultLfMergeSettings.MongoAuthSource;
+		public string MongoUsername => Environment.GetEnvironmentVariable(MagicStrings.SettingsEnvVar_MongoUsername) ?? DefaultLfMergeSettings.MongoUsername;
+		public string MongoPassword => Environment.GetEnvironmentVariable(MagicStrings.SettingsEnvVar_MongoPassword) ?? DefaultLfMergeSettings.MongoPassword;
+		private string EncodedUsername => Uri.EscapeUriString(MongoUsername);
+		private string EncodedPassword => Uri.EscapeUriString(MongoPassword);
+
 		public string MongoMainDatabaseName => Environment.GetEnvironmentVariable(MagicStrings.SettingsEnvVar_MongoMainDatabaseName) ?? DefaultLfMergeSettings.MongoMainDatabaseName;
 
 		/// <summary>
@@ -65,6 +71,9 @@ public bool VerboseProgress {
 		public bool CommitWhenDone { get; internal set; }
 
 		public string MongoDbHostNameAndPort { get { return String.Format("{0}:{1}", MongoHostname, MongoPort.ToString()); } }
+		public string MongoDbHostPortAndAuth => string.IsNullOrEmpty(MongoUsername) || string.IsNullOrEmpty(MongoPassword)
+			? string.Format("{0}:{1}", MongoHostname, MongoPort.ToString())
+			: string.Format("{0}:{1}@{2}:{3}", EncodedUsername, EncodedPassword, MongoHostname, MongoPort.ToString());
 
 		private string QueueDirectory { get; set; }