TransformValue

type: "io.kestra.plugin.transform.grok.TransformValue"

Parse arbitrary text and structure it using Grok expressions.

The TransformValue task is similar to the famous Logstash Grok filter from the ELK stack. It is particularly useful for transforming unstructured data such as logs into a structured, indexable, and queryable data structure.

The TransformValue ships with all the default patterns as defined You can find them here: https://github.com/kestra-io/plugin-transform/tree/main/plugin-transform-grok/src/main/resources/patterns.

Examples

Consume, parse, and structure logs events from Kafka topic.

id: grok_transform_value
namespace: company.team

tasks:
  - id: transform_value
    type: io.kestra.plugin.transform.grok.TransformValue
    pattern: "%{TIMESTAMP_ISO8601:logdate} %{LOGLEVEL:loglevel} %{GREEDYDATA:message}"
    from: "{{ trigger.value }}"

  - id: log_on_warn
    type: io.kestra.plugin.core.flow.If
    condition: "{{ grok.value['LOGLEVEL'] == 'ERROR' }}"
    then:
      - id: when_true
        type: io.kestra.plugin.core.log.Log
        message: "{{ outputs.transform_value.value }}"

triggers:
  - id: realtime_trigger
    type: io.kestra.plugin.kafka.RealtimeTrigger
    topic: test_kestra
    properties:
      bootstrap.servers: localhost:9092
    serdeProperties:
      schema.registry.url: http://localhost:8085
      keyDeserializer: STRING
      valueDeserializer: STRING
    groupId: kafkaConsumerGroupId

Properties

from

• Type: string
• Dynamic: ✔️
• Required: ✔️

The value to parse.

breakOnFirstMatch

• Type: boolean
• Dynamic: ❌
• Required: ❌
• Default: true

If true, break on first match.

The first successful match by grok will result in the task being finished. Set to false if you want the task to try all configured patterns.

keepEmptyCaptures

• Type: boolean
• Dynamic: ❌
• Required: ❌
• Default: false

If true, keep empty captures.

When an optional field cannot be captured, the empty field is retained in the output. Set false if you want empty optional fields to be filtered out.

namedCapturesOnly

• Type: boolean
• Dynamic: ❌
• Required: ❌
• Default: true

If true, only store named captures from grok.

pattern

• Type: string
• Dynamic: ❌
• Required: ❌

The Grok pattern to match.

patternDefinitions

• Type: object
• SubType: string
• Dynamic: ❌
• Required: ❌

Custom pattern definitions.

A map of pattern-name and pattern pairs defining custom patterns to be used by the current tasks. Patterns matching existing names will override the pre-existing definition.

patterns

• Type: array
• SubType: string
• Dynamic: ❌
• Required: ❌

The list of Grok patterns to match.

patternsDir

• Type: array
• SubType: string
• Dynamic: ❌
• Required: ❌

List of user-defined pattern directories.

Directories must be paths relative to the working directory.