[#8] [add] impl

Author: i4004

src/Etcd.Microsoft.Extensions.Configuration/Auth/EnvironmentCredentialsFactory.cs

@@ -0,0 +1,22 @@
+namespace Etcd.Microsoft.Extensions.Configuration.Auth;
+
+/// <summary>
+/// Provides a factory for creating environment-based credentials for etcd.
+/// </summary>
+public static class EnvironmentCredentialsFactory
+{
+	/// <summary>
+	/// Tries to create credentials from environment variables.
+	/// </summary>
+	/// <returns>Credentials if both username and password are set; otherwise, null.</returns>
+	public static ICredentials? TryCreate()
+	{
+		var userName = EtcdApplicationEnvironment.UserName;
+		var password = EtcdApplicationEnvironment.Password;
+
+		if (string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(password))
+			return null;
+
+		return new Credentials(userName, password);
+	}
+}

src/Etcd.Microsoft.Extensions.Configuration/ConfigurationBuilderExtensions.cs

@@ -98,6 +98,8 @@ public static IConfigurationBuilder AddEtcd(this IConfigurationBuilder configura
 	{
 		ArgumentNullException.ThrowIfNull(configurationBuilder);
 
+		credentials = EnvironmentCredentialsFactory.TryCreate() ?? credentials;
+
 		var clientFactory = new EtcdClientFactory(settings);
 		var client = new EtcdKeyValueClient(clientFactory, credentials, enableWatch, unwatchOnDispose);
 

src/Etcd.Microsoft.Extensions.Configuration/EtcdApplicationEnvironment.cs

@@ -7,26 +7,90 @@ namespace Etcd.Microsoft.Extensions.Configuration;
 /// </summary>
 public static class EtcdApplicationEnvironment
 {
+	private static string _connectionStringEnvironmentVariableName = "ETCD_CLIENT_CONNECTION_STRING";
+	private static string _userNameEnvironmentVariableName = "ETCD_CLIENT_USER_NAME";
+	private static string _passwordEnvironmentVariableName = "ETCD_CLIENT_PASSWORD";
+	private static string? _connectionString;
+
 	/// <summary>
 	/// The connection string environment variable name
 	/// </summary>
-	public const string ConnectionStringEnvironmentVariableName = "ETCD_CLIENT_CONNECTION_STRING";
+	public static string ConnectionStringEnvironmentVariableName
+	{
+		get => _connectionStringEnvironmentVariableName;
+		set
+		{
+			if (string.IsNullOrEmpty(value))
+				throw new ArgumentNullException(nameof(value));
 
-	private static string? _connectionString;
+			_connectionStringEnvironmentVariableName = value;
+		}
+	}
+
+	/// <summary>
+	/// The client user name environment variable name
+	/// </summary>
+	public static string UserNameEnvironmentVariableName
+	{
+		get => _userNameEnvironmentVariableName;
+		set
+		{
+			if (string.IsNullOrEmpty(value))
+				throw new ArgumentNullException(nameof(value));
+
+			_userNameEnvironmentVariableName = value;
+		}
+	}
+
+	/// <summary>
+	/// The client password environment variable name
+	/// </summary>
+	public static string PasswordEnvironmentVariableName
+	{
+		get => _passwordEnvironmentVariableName;
+		set
+		{
+			if (string.IsNullOrEmpty(value))
+				throw new ArgumentNullException(nameof(value));
+
+			_passwordEnvironmentVariableName = value;
+		}
+	}
 
 	/// <summary>
 	/// Gets or sets the connection string.
 	/// </summary>
 	/// <value>
 	/// The connection string.
 	/// </value>
-	/// <exception cref="System.ArgumentNullException">value</exception>
+	/// <exception cref="ArgumentNullException">value</exception>
 	public static string? ConnectionString
 	{
-		get
+		get => _connectionString ??= Environment.GetEnvironmentVariable(ConnectionStringEnvironmentVariableName);
+		set
 		{
-			return _connectionString ??= Environment.GetEnvironmentVariable(ConnectionStringEnvironmentVariableName);
+			if (string.IsNullOrEmpty(value))
+				throw new ArgumentNullException(nameof(value));
+
+			_connectionString = value;
 		}
-		set => _connectionString = value ?? throw new ArgumentNullException(nameof(value));
 	}
+
+	/// <summary>
+	/// Gets or sets the user name.
+	/// </summary>
+	/// <value>
+	/// The user name.
+	/// </value>
+	/// <exception cref="ArgumentNullException">value</exception>
+	public static string? UserName => Environment.GetEnvironmentVariable(UserNameEnvironmentVariableName);
+
+	/// <summary>
+	/// Gets or sets the password.
+	/// </summary>
+	/// <value>
+	/// The password.
+	/// </value>
+	/// <exception cref="ArgumentNullException">value</exception>
+	public static string? Password => Environment.GetEnvironmentVariable(PasswordEnvironmentVariableName);
 }