Kafka Connect: Add static table to topics mapping using new property

docs/docs/kafka-connect.md

@@ -63,6 +63,7 @@ for exactly-once semantics. This requires Kafka 2.5 or later.
 | iceberg.tables                             | Comma-separated list of destination tables                                                                       |
 | iceberg.tables.dynamic-enabled             | Set to `true` to route to a table specified in `routeField` instead of using `routeRegex`, default is `false`    |
 | iceberg.tables.route-field                 | For multi-table fan-out, the name of the field used to route records to tables                                   |
+| iceberg.tables.topic-to-table-map          | For topic to table mapping, statically map topic name to table identifier to route records                       |
 | iceberg.tables.default-commit-branch       | Default branch for commits, main is used if not specified                                                        |
 | iceberg.tables.default-id-columns          | Default comma-separated list of columns that identify a row in tables (primary key)                              |
 | iceberg.tables.default-partition-by        | Default comma-separated list of partition field names to use when creating tables                                |
@@ -364,6 +365,46 @@ See above for creating two tables.
 }
 ```
 
+### Topic mapped to table identifier, static routing
+
+This example writes to tables based on their mappings from connector config. For example, `events_list` is mapped to `db.event_get_log` table and `events_create` is mapped to `db.event_add_log`.
+
+#### Create two destination tables
+
+```sql
+CREATE TABLE db.event_get_log (
+    id STRING,
+    type STRING,
+    ts TIMESTAMP,
+    payload STRING)
+PARTITIONED BY (hours(ts));
+
+CREATE TABLE db.event_add_log (
+    id STRING,
+    type STRING,
+    ts TIMESTAMP,
+    payload STRING)
+PARTITIONED BY (hours(ts));
+```
+
+#### Connector config
+
+```json
+{
+"name": "events-sink",
+"config": {
+    "connector.class": "org.apache.iceberg.connect.IcebergSinkConnector",
+    "tasks.max": "2",
+    "topics": "events_list,events_create",
+    "iceberg.tables.topic-to-table-map": "event_list:db.event_get_log,events_create:db.event_add_log",
+    "iceberg.catalog.type": "rest",
+    "iceberg.catalog.uri": "https://localhost",
+    "iceberg.catalog.credential": "<credential>",
+    "iceberg.catalog.warehouse": "<warehouse name>"
+    }
+}
+```
+
 ## SMTs for the Apache Iceberg Sink Connector
 
 This project contains some SMTs that could be useful when transforming Kafka data for use by
@@ -530,3 +571,4 @@ easy processing of arrays by downstream clients.
 Value document will convert the array into a struct of structs in the similar way as done by BSON serialization.
 The main struct contains fields named _0, _1, _2 etc. where the name represents the index of the element in the array.
 Every element is then passed as the value for the given field.
+=======

kafka-connect/kafka-connect/src/main/java/org/apache/iceberg/connect/IcebergSinkConfig.java

@@ -65,6 +65,7 @@ public class IcebergSinkConfig extends AbstractConfig {
   private static final String WRITE_PROP_PREFIX = "iceberg.tables.write-props.";
 
   private static final String CATALOG_NAME_PROP = "iceberg.catalog";
+  private static final String TOPIC_TO_TABLE_MAP_PROP = "iceberg.tables.topic-to-table-map";
   private static final String TABLES_PROP = "iceberg.tables";
   private static final String TABLES_DYNAMIC_PROP = "iceberg.tables.dynamic-enabled";
   private static final String TABLES_ROUTE_FIELD_PROP = "iceberg.tables.route-field";
@@ -115,6 +116,12 @@ public static String version() {
 
   private static ConfigDef newConfigDef() {
     ConfigDef configDef = new ConfigDef();
+    configDef.define(
+        TOPIC_TO_TABLE_MAP_PROP,
+        ConfigDef.Type.LIST,
+        null,
+        Importance.LOW,
+        "Comma-delimited list of topic to table mappings");
     configDef.define(
         TABLES_PROP,
         ConfigDef.Type.LIST,
@@ -327,6 +334,18 @@ public String catalogName() {
     return getString(CATALOG_NAME_PROP);
   }
 
+  public Map<String, String> topicToTableMap() {
+    Map<String, String> topicToTableMap = Maps.newHashMap();
+    for (String topicToTable : getList(TOPIC_TO_TABLE_MAP_PROP)) {
+      List<String> propsplit = Splitter.on(':').splitToList(topicToTable.trim());
+      if (propsplit.size() == 2) {
+        topicToTableMap.put(propsplit.get(0).trim(), propsplit.get(1).trim());
+      }
+    }
+    LOG.debug("Config: topicToTableMap: {}", topicToTableMap);
+    return topicToTableMap;
+  }
+
   public List<String> tables() {
     return getList(TABLES_PROP);
   }

kafka-connect/kafka-connect/src/main/java/org/apache/iceberg/connect/data/SinkWriter.java

@@ -84,11 +84,26 @@ private void save(SinkRecord record) {
 
     if (config.dynamicTablesEnabled()) {
       routeRecordDynamically(record);
+    } else if (config.topicToTableMap().size() > 0) {
+      routeRecordByMap(record);
     } else {
       routeRecordStatically(record);
     }
   }
 
+  private void routeRecordByMap(SinkRecord record) {
+    Map<String, String> topicToTableMap = config.topicToTableMap();
+    String topicName = record.topic();
+    String tableName = topicToTableMap.get(topicName);
+
+    if (tableName == null) {
+      routeRecordStatically(record);
+      return;
+    }
+
+    writerForTable(tableName, record, false).write(record);
+  }
+
   private void routeRecordStatically(SinkRecord record) {
     String routeField = config.tablesRouteField();
 

kafka-connect/kafka-connect/src/test/java/org/apache/iceberg/connect/data/TestSinkWriter.java

@@ -62,6 +62,7 @@ public class TestSinkWriter {
           optional(2, "data", Types.StringType.get()),
           optional(3, "date", Types.StringType.get()));
   private static final String ROUTE_FIELD = "fld";
+  private static final String TOPIC_NAME = "topic";
 
   @BeforeEach
   public void before() {
@@ -235,6 +236,21 @@ public void testDynamicNoRoute() {
     assertThat(writerResults).hasSize(0);
   }
 
+  @Test
+  public void testTopicToTableMapRoute() {
+    IcebergSinkConfig config = mock(IcebergSinkConfig.class);
+    when(config.topicToTableMap())
+        .thenReturn(ImmutableMap.of(TOPIC_NAME, TABLE_IDENTIFIER.toString()));
+    when(config.tableConfig(any())).thenReturn(mock(TableSinkConfig.class));
+
+    Map<String, Object> value = ImmutableMap.of(TOPIC_NAME, TABLE_IDENTIFIER.toString());
+
+    List<IcebergWriterResult> writerResults = sinkWriterTest(value, config);
+    assertThat(writerResults.size()).isEqualTo(1);
+    IcebergWriterResult writerResult = writerResults.get(0);
+    assertThat(writerResult.tableIdentifier()).isEqualTo(TABLE_IDENTIFIER);
+  }
+
   private List<IcebergWriterResult> sinkWriterTest(
       Map<String, Object> value, IcebergSinkConfig config) {
     IcebergWriterResult writeResult =
@@ -255,7 +271,7 @@ private List<IcebergWriterResult> sinkWriterTest(
     Instant now = Instant.now().truncatedTo(ChronoUnit.MILLIS);
     SinkRecord rec =
         new SinkRecord(
-            "topic",
+            TOPIC_NAME,
             1,
             null,
             "key",
@@ -268,7 +284,7 @@ private List<IcebergWriterResult> sinkWriterTest(
 
     SinkWriterResult result = sinkWriter.completeWrite();
 
-    Offset offset = result.sourceOffsets().get(new TopicPartition("topic", 1));
+    Offset offset = result.sourceOffsets().get(new TopicPartition(TOPIC_NAME, 1));
     assertThat(offset).isNotNull();
     assertThat(offset.offset()).isEqualTo(101L); // should be 1 more than current offset
     assertThat(offset.timestamp()).isEqualTo(now.atOffset(ZoneOffset.UTC));