feat: Support setting serverId with SERVERPOD_SERVER_ID env var (serverpod#3238)

Added the ability to set the serverId from environment variables (SERVER_ID) in addition to the command line argument
(--server-id). If both options are provided, the command line argument takes precedence.

Closes [serverpod#2832](serverpod#2832)

Author: henycave

packages/serverpod/lib/src/server/serverpod.dart

@@ -335,10 +335,23 @@ class Serverpod {
     stdout.writeln(commandLineArgs.toString());
 
     _runMode = commandLineArgs.runMode;
-    serverId = commandLineArgs.serverId;
+    // Load passwords
+    _passwordManager = PasswordManager(runMode: runMode);
+    _passwords = _passwordManager.loadPasswords();
+
+    // Load config
+    this.config = config ??
+        ServerpodConfig.load(
+          _runMode,
+          commandLineArgs.serverId,
+          _passwords,
+        );
+
+    logVerbose(this.config.toString());
+    serverId = this.config.serverId;
 
     try {
-      _innerInitializeServerpod(commandLineArgs, config: config);
+      _innerInitializeServerpod();
     } catch (e, stackTrace) {
       _reportException(e, stackTrace,
           message: 'Error in Serverpod initialization');
@@ -348,34 +361,17 @@ class Serverpod {
     stdout.writeln('SERVERPOD initialized, time: ${DateTime.now().toUtc()}');
   }
 
-  void _innerInitializeServerpod(
-    CommandLineArgs commandLineArgs, {
-    ServerpodConfig? config,
-  }) {
+  void _innerInitializeServerpod() {
     _instance = this;
     _internalSerializationManager = internal.Protocol();
-
-    // Load passwords
-    _passwordManager = PasswordManager(runMode: runMode);
-    _passwords = _passwordManager.loadPasswords();
-
-    // Load config
-    this.config = config ??
-        ServerpodConfig.load(
-          _runMode,
-          serverId,
-          _passwords,
-        );
-    logVerbose(this.config.toString());
-
-    Features(this.config);
+    Features(config);
 
     // Create a temporary log manager with default settings, until we have
     // loaded settings from the database.
     _updateLogSettings(_defaultRuntimeSettings);
 
     // Setup database
-    var databaseConfiguration = this.config.database;
+    var databaseConfiguration = config.database;
     if (Features.enableDatabase && databaseConfiguration != null) {
       _databasePoolManager = DatabasePoolManager(
         serializationManager,
@@ -398,7 +394,7 @@ class Serverpod {
     }
 
     // Setup Redis
-    var redis = this.config.redis;
+    var redis = config.redis;
     if (Features.enableRedis && redis != null) {
       redisController = RedisController(
         host: redis.host,
@@ -410,7 +406,7 @@ class Serverpod {
 
     _caches = Caches(
       serializationManager,
-      this.config,
+      config,
       serverId,
       redisController,
     );
@@ -420,7 +416,7 @@ class Serverpod {
     server = Server(
       serverpod: this,
       serverId: serverId,
-      port: this.config.apiServer.port,
+      port: config.apiServer.port,
       serializationManager: serializationManager,
       databasePoolManager: _databasePoolManager,
       passwords: _passwords,

packages/serverpod_shared/lib/src/config.dart

@@ -94,6 +94,8 @@ class ServerpodConfig {
     Map configMap, {
     Map<String, String> environment = const {},
   }) {
+    serverId = _readServerId(configMap, environment, serverId);
+
     var apiConfig = _apiConfigMap(configMap, environment);
     if (apiConfig == null) {
       throw _ServerpodApiServerConfigMissing();
@@ -594,6 +596,20 @@ int _readMaxRequestSize(
   return maxRequestSize;
 }
 
+String _readServerId(
+  Map<dynamic, dynamic> configMap,
+  Map<String, String> environment,
+  String serverIdFromCommandLineArg,
+) {
+  if (serverIdFromCommandLineArg != 'default') {
+    return serverIdFromCommandLineArg;
+  }
+  var serverId = environment[ServerpodEnv.serverId.envVariable] ??
+      configMap[ServerpodEnv.serverId.configKey] ??
+      'default';
+  return serverId;
+}
+
 /// Validates that a JSON configuration contains all required keys, and that
 /// the values have the correct types.
 ///

packages/serverpod_shared/lib/src/environment_variables.dart

@@ -109,7 +109,10 @@ enum ServerpodEnv {
   sessionPersistentLogEnabled,
 
   /// True if session console logging is enabled.
-  sessionConsoleLogEnabled;
+  sessionConsoleLogEnabled,
+
+  /// The id of the server.
+  serverId;
 
   /// The key used in the environment configuration file.
   String get configKey {
@@ -140,6 +143,7 @@ enum ServerpodEnv {
       (ServerpodEnv.maxRequestSize) => 'maxRequestSize',
       (ServerpodEnv.sessionPersistentLogEnabled) => 'persistentEnabled',
       (ServerpodEnv.sessionConsoleLogEnabled) => 'consoleEnabled',
+      (ServerpodEnv.serverId) => 'serverId',
     };
   }
 
@@ -177,6 +181,7 @@ enum ServerpodEnv {
         'SERVERPOD_SESSION_PERSISTENT_LOG_ENABLED',
       (ServerpodEnv.sessionConsoleLogEnabled) =>
         'SERVERPOD_SESSION_CONSOLE_LOG_ENABLED',
+      (ServerpodEnv.serverId) => 'SERVERPOD_SERVER_ID',
     };
   }
 }

packages/serverpod_shared/test/config_test.dart

@@ -978,4 +978,119 @@ redis:
 
     expect(config.redis?.enabled, isTrue);
   });
+
+  test(
+      'Given a Serverpod config with server id when loading from Map then serverId configuration matches supplied value.',
+      () {
+    var serverpodConfig = '''
+apiServer:
+  port: 8080
+  publicHost: localhost
+  publicPort: 8080
+  publicScheme: http
+serverId: testServer1
+''';
+
+    var config = ServerpodConfig.loadFromMap(
+      runMode,
+      serverId,
+      passwords,
+      loadYaml(serverpodConfig),
+    );
+
+    expect(config.serverId, 'testServer1');
+  });
+
+  test(
+      'Given a Serverpod config with only the api server configuration but the environment variables containing the server id when loading from Map then the server id matches supplied value.',
+      () {
+    var config = ServerpodConfig.loadFromMap(
+      runMode,
+      serverId,
+      passwords,
+      {
+        'apiServer': {
+          'port': 8080,
+          'publicHost': 'localhost',
+          'publicPort': 8080,
+          'publicScheme': 'http',
+        },
+      },
+      environment: {
+        'SERVERPOD_SERVER_ID': 'testServer1',
+      },
+    );
+
+    expect(config.serverId, 'testServer1');
+  });
+
+  test(
+      'Given a Serverpod config with only the api server configuration but the server id given as an argument then the server id matches supplied value.',
+      () {
+    var config = ServerpodConfig.loadFromMap(
+      runMode,
+      'testServer1',
+      passwords,
+      {
+        'apiServer': {
+          'port': 8080,
+          'publicHost': 'localhost',
+          'publicPort': 8080,
+          'publicScheme': 'http',
+        },
+      },
+    );
+
+    expect(config.serverId, 'testServer1');
+  });
+
+  test(
+      'Given a Serverpod config with server id when loading from Map and the environment variables containing the server id but the server id given as an argument is the default value then the server id from environment takes the precedence.',
+      () {
+    var serverpodConfig = '''
+apiServer:
+  port: 8080
+  publicHost: localhost
+  publicPort: 8080
+  publicScheme: http
+serverId: testServerIdFromConfig
+''';
+
+    var config = ServerpodConfig.loadFromMap(
+      runMode,
+      serverId,
+      passwords,
+      loadYaml(serverpodConfig),
+      environment: {
+        'SERVERPOD_SERVER_ID': 'testServerIdFromEnv',
+      },
+    );
+
+    expect(config.serverId, 'testServerIdFromEnv');
+  });
+
+  test(
+      'Given a Serverpod config with server id when loading from Map and the environment variables containing the server id and the server id given as an argument is a custom defined value then the server id from the argument takes the precedence.',
+      () {
+    var serverpodConfig = '''
+apiServer:
+  port: 8080
+  publicHost: localhost
+  publicPort: 8080
+  publicScheme: http
+serverId: testServerIdFromConfig
+''';
+
+    var config = ServerpodConfig.loadFromMap(
+      runMode,
+      'testServerIdFromArg',
+      passwords,
+      loadYaml(serverpodConfig),
+      environment: {
+        'SERVERPOD_SERVER_ID': 'testServerIdFromEnv',
+      },
+    );
+
+    expect(config.serverId, 'testServerIdFromArg');
+  });
 }