Add Fields

Overview

The Add Fields processor adds new fields to incoming telemetry records. It can be used to enrich logs with static values before the data is forwarded downstream.

Supported types: Logs

Configuration

Parameter	Type	Default	Required	Description
ottl_expression	string	none	No	OTTL expression used to conditionally apply the field additions.

Rules

When building the ottl_expression, the UI exposes rule-based conditions.

Attributes

Parameter	Type	Description
Attribute Key	string	The attribute key to evaluate. Supported values: attribute; resource; log; span; metric (fields: aggregation_temporality; description; is_monotonic; name; type; unit); datapoint (fields: count; negative.offset; positive.offset; scale; sum; value_double; value_int; zero_count)
Operator	string	The operator to use for comparison. Supported values: equals; not equals; starts with; ends with; contains; regex; ==; !=; <; >; >=; <=; is boolean; is integer; is double; is map; is string; exists; not exists
Value	string	The value to compare against

Note: Multiple rules can be combined in the UI using logical operators such as AND or OR, and the resulting rule set is converted into the final ottl_expression.

Fields To Add/Modify

Each item in fields defines one field operation to apply.

Parameter	Type	Default	Required	Description
field_type	string	body	Yes	Target area where the field should be added or modified. Supported values: body attribute resource.
action	string	upsert	Yes	Operation to apply to the target field. Supported values: insert update upsert.
field	string	none	Yes	Field key or path to add or modify.
value	string	none	Yes	Value assigned to the target field.

Example Configuration

{
  "ottl_expression": "", // default: none
  "fields": [
    // required
    {
      "field_type": "body", // required, default: "body"
      "action": "upsert", // required, default: "upsert"
      "field": "", // required, default: none
      "value": "", // required, default: none
    },
  ],
}