add default username

Author: jerrinot

connector/src/main/java/io/questdb/kafka/QuestDBSinkConnectorConfig.java

@@ -59,7 +59,7 @@ public static ConfigDef conf() {
                 .define(DESIGNATED_TIMESTAMP_COLUMN_NAME_CONFIG, Type.STRING, null, Importance.MEDIUM, DESIGNATED_TIMESTAMP_COLUMN_NAME_DOC)
                 .define(INCLUDE_KEY_CONFIG, Type.BOOLEAN, true, Importance.MEDIUM, INCLUDE_KEY_DOC)
                 .define(SYMBOL_COLUMNS_CONFIG, Type.STRING, null, Importance.MEDIUM, SYMBOL_COLUMNS_DOC)
-                .define(USERNAME, Type.STRING, null, Importance.MEDIUM, USERNAME_DOC)
+                .define(USERNAME, Type.STRING, "admin", Importance.MEDIUM, USERNAME_DOC)
                 .define(TOKEN, Type.STRING, null, Importance.MEDIUM, TOKEN_DOC)
                 .define(TLS, Type.BOOLEAN, false, Importance.MEDIUM, TLS_DOC);
     }

connector/src/main/java/io/questdb/kafka/QuestDBSinkTask.java

@@ -50,11 +50,12 @@ private Sender createSender() {
         if (config.isTls()) {
             builder.enableTls();
         }
-        if (config.getUsername() != null) {
-            if (config.getToken() == null) {
-                throw new ConnectException("Token is required when username is provided");
+        if (config.getToken() != null) {
+            String username = config.getUsername();
+            if (username == null || username.equals("")) {
+                throw new ConnectException("Username cannot be empty when using ILP authentication");
             }
-            builder.enableAuth(config.getUsername()).authToken(config.getToken());
+            builder.enableAuth(username).authToken(config.getToken());
         }
         Sender rawSender = builder.build();
         String symbolColumns = config.getSymbolColumns();