Kafka Connect InsertHeader SMT Usage Reference for Confluent Cloud¶
The following provides usage information for the Apache Kafka® SMT
org.apache.kafka.connect.transforms.InsertHeader.
Description¶
Inserts a header for each record.
Example¶
This configuration snippet shows how to use InsertHeader to insert a header
named app.id with the literal value best-app-ever on each record.
"transforms": "insertAppIdHeader",
"transforms.insertAppIdHeader.type": "org.apache.kafka.connect.transforms.InsertHeader",
"transforms.insertAppIdHeader.header": "app.id",
"transforms.insertAppIdHeader.value.literal": "best-app-ever"
Before: No header named app.id or value in records.
After: Each record contains header value best-app-ever.
In the example above, Connect parses the literal value best-app-ever into
STRING type.
The following lists sample values for the value property and the data types that
Connect parses the value into:
1234is parsed into INT16 type.trueis parsed into BOOLEAN type.nullis parsed into null (with no type).[-3, 0, 5]is parsed into an ARRAY of INT8 elements.{3.4: 4761, -5.9: -9753186420}is parsed into a MAP with FLOAT32 keys and INT64 values.
Properties¶
| Name | Description | Type | Default | Valid Values | Importance |
|---|---|---|---|---|---|
header |
Header name to use with the transformation. | string | non-null string | medium | |
value |
The header value to add to each record. If the value appears to be a primitive literal (such as a 32-bit integer, boolean, or null) or a complex literal (such as an array or map denoted with JSON-like syntax), the value is parsed and added to the header as that type. Otherwise, the raw string for this property is used as-is. | string | non-null string | medium |
Predicates¶
Transformations can be configured with predicates so that the transformation is applied only to records which satisfy a condition. You can use predicates in a transformation chain and, when combined with the Kafka Connect Filter (Kafka) SMT Usage Reference for Confluent Cloud, predicates can conditionally filter out specific records. For details and examples, see Predicates.