Script processor
editScript processor
editRuns an inline or stored script on incoming documents. The
script runs in the ingest
context.
The script processor uses the script cache to avoid recompiling the script for each incoming document. To improve performance, ensure the script cache is properly sized before using a script processor in production.
Table 38. Script options
Name | Required | Default | Description |
---|---|---|---|
|
no |
"painless" |
|
|
no |
- |
ID of a stored script.
If no |
|
no |
- |
Inline script.
If no |
|
no |
- |
Object containing parameters for the script. |
|
no |
- |
Description of the processor. Useful for describing the purpose of the processor or its configuration. |
|
no |
- |
Conditionally execute the processor. See Conditionally run a processor. |
|
no |
|
Ignore failures for the processor. See Handling pipeline failures. |
|
no |
- |
Handle failures for the processor. See Handling pipeline failures. |
|
no |
- |
Identifier for the processor. Useful for debugging and metrics. |
Access source fields
editThe script processor parses each incoming document’s JSON source fields into a
set of maps, lists, and primitives. To access these fields with a Painless
script, use the
map access
operator: ctx['my-field']
. You can also use the shorthand ctx.<my-field>
syntax.
The script processor does not support the ctx['_source']['my-field']
or
ctx._source.<my-field>
syntaxes.
The following processor uses a Painless script to extract the tags
field from
the env
source field.
response = client.ingest.simulate( body: { pipeline: { processors: [ { script: { description: "Extract 'tags' from 'env' field", lang: 'painless', source: "\n String[] envSplit = ctx['env'].splitOnToken(params['delimiter']);\n ArrayList tags = new ArrayList();\n tags.add(envSplit[params['position']].trim());\n ctx['tags'] = tags;\n ", params: { delimiter: '-', position: 1 } } } ] }, docs: [ { _source: { env: 'es01-prod' } } ] } ) puts response
POST _ingest/pipeline/_simulate { "pipeline": { "processors": [ { "script": { "description": "Extract 'tags' from 'env' field", "lang": "painless", "source": """ String[] envSplit = ctx['env'].splitOnToken(params['delimiter']); ArrayList tags = new ArrayList(); tags.add(envSplit[params['position']].trim()); ctx['tags'] = tags; """, "params": { "delimiter": "-", "position": 1 } } } ] }, "docs": [ { "_source": { "env": "es01-prod" } } ] }
The processor produces:
{ "docs": [ { "doc": { ... "_source": { "env": "es01-prod", "tags": [ "prod" ] } } } ] }
Access metadata fields
editYou can also use a script processor to access metadata fields. The following
processor uses a Painless script to set an incoming document’s _index
.
response = client.ingest.simulate( body: { pipeline: { processors: [ { script: { description: 'Set index based on `lang` field and `dataset` param', lang: 'painless', source: "\n ctx['_index'] = ctx['lang'] + '-' + params['dataset'];\n ", params: { dataset: 'catalog' } } } ] }, docs: [ { _index: 'generic-index', _source: { lang: 'fr' } } ] } ) puts response
POST _ingest/pipeline/_simulate { "pipeline": { "processors": [ { "script": { "description": "Set index based on `lang` field and `dataset` param", "lang": "painless", "source": """ ctx['_index'] = ctx['lang'] + '-' + params['dataset']; """, "params": { "dataset": "catalog" } } } ] }, "docs": [ { "_index": "generic-index", "_source": { "lang": "fr" } } ] }
The processor changes the document’s _index
to fr-catalog
from
generic-index
.
{ "docs": [ { "doc": { ... "_index": "fr-catalog", "_source": { "lang": "fr" } } } ] }